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1

Baynham, Mark Kevin. "Gibberellin plant growth hormones." Thesis, University of Sussex, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328329.

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2

Weir, A. J. "#alpha#-ketogutarate dependent gibberellin hydroxylases and plant growth regultion." Thesis, University of Bristol, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233760.

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3

Zhang, Xunzhong. "Influence of Plant Growth Regulators on Turfgrass Growth, Antioxidant Status, and Drought Tolerance." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30739.

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A series of studies were conducted to examine the antioxidant status, drought and disease tolerance, and growth response to foliar application of soluble seaweed (Ascophyllum nodosum) extracts (SE) and humic acid (HA; 25% active HA or 2.9% active HA) in tall fescue (Festuca arundinacea Schreb), Kentucky bluegrass (Poa pratensis L.) and creeping bentgrass (Agrostis palusttis Huds.) grown under low (-0.5 MPa) and high (-0.03 MPa) soil moisture environments. Foliar application of humic acid (2.9 % active HA) at 23.7 and 47.4 l/ha improved leaf water status, shoot and root development in tall fescue, Kentucky bluegrass and creeping bentgrass grown under drought. Humic acid (2.9% active HA) at 15.5 l/ha or SE at 326 g/ha significantly reduced dollarspot incidence and improved turf quality in creeping bentgrass. Drought stress induced an increase of antioxidants alpha-tocopherol and ascorbic acid concentrations in the three turfgrass species. In the experiment with Kentucky bluegrass, drought stress increased beta-carotene concentration, but did not significantly influence superoxide dismutase (SOD) activity. Foliar application of humic acid (25% active HA) at 5 l/ha and/or SE at 326 g/ha consistently enhanced alpha-tocopherol and ascorbic acid concentrations, leaf water status, and growth in the three cool-season turfgrass species grown under low and high soil moisture environments. In the experiment with Kentucky bluegrass, application of HA at 5 l/ha plus SE at 326 g/ha also increased beta-carotene content and SOD activity under low and high soil moisture environments. There were close positive correlations between the antioxidant status and shoot or root growth in the three turfgrass species regardless of soil moisture levels. The antioxidant SOD activity, photosynthetic capacity in terms of Fvm690, and chlorophyll content in terms of Fm730/Fm690 exhibited a seasonal fluctuation in endophyte [Neotiphodium coenophialum (Morgan Jones and Gams) Glenn, Bacon, Price and Hanlin] -free and endophyte-infected tall fescue. Application of SE enhanced SOD activity, photosynthetic capacity, and chlorophyll content in tall fescue, especially at 4 weeks after SE treatment. The SOD activity, photosynthetic capacity and chlorophyll content were not significantly influenced by the endophyte infection. A close positive correlation between SOD and photosynthetic capacity during the summer was found in endophyte-free and endophyte-infected tall fescue.
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4

McCoy, Mark Christopher. "The effects of phytohormones on growth and artemisinin production in hairy root cultures of artemisia annua l." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0529103-162012/.

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5

Xing, Ti. "Hormone binding in plants." Thesis, De Montfort University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280511.

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6

Ververidis, Philippos. "Characterisation and partial purification of the enzyme responsible for ethylene synthesis from 1-aminocyclopropane-1carboxylic acid in plant tissues." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303175.

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7

Feys, Bart Julienne Frans. "Towards positional cloning of COI1, an arabidopsis gene controlling the response to coronatine and methyl jasmonate." Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317974.

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8

Yuan, Kun Wysocka-Diller Joanna Singh Narendra K. "Functional and genetic analysis of plant transcription factors involved in the plant growth under various environmental conditions." Auburn, Ala, 2008. http://repo.lib.auburn.edu/2007%20Fall%20Dissertations/Yuan_Kun_37.pdf.

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9

Guinn, Gene, and Donald L. Brummett. "Irrigation and Nitrogen Effects on Plant Hormones, Boll Retention, and Growth of Fruiting Branches." College of Agriculture, University of Arizona (Tucson, AZ), 1987. http://hdl.handle.net/10150/204460.

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An experiment was conducted in Phoenix in 1986 to determine effects of water and N deficits on ABA and IAA concentrations in young bolls and their abscission zones in relation to boll retention, and to determine the effects of N on growth of fruiting branches through the season. Water deficit decreased boll retention, decreased the concentration of free IAA in bolls and their abscission zones, and increased ABA in bolls and abscission zones. But, the concentration of ester IAA increased with water deficit (in contrast to free IAA). Because ester IAA resists degradation during stress, it may facilitate recovery when stress is relieved and some of it is converted to free IAA. N-deficiency symptoms were mild and did not appear early in the season. N had no effect on the ABA and IAA contents of bolls and their abscission zones, and had only a small effect on growth of fruiting branches. The N test is to be repeated in 1987 when N deficiency should be more severe.
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10

Wheelhouse, Nicholas Mark. "The effect of amino acids on growth hormone action in ovine hepatocytes." Thesis, University of Aberdeen, 1999. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=185765.

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Many of the anabolic effects of growth hormone (GH) are indirect, occurring through GH-stimulated production of insulin-like growth factor-I (IGF-I) by the liver. As well as being GH regulated, plasma IGF-I concentrations have been demonstrated to be dependent upon protein nutrition, with low protein diets being associated with reduced plasma IGF-I concentrations. This effect cannot be reversed by GH, suggesting that liver sensitivity to GH is impaired. To investigate the mechanisms through which protein supply affects GH sensitivity, primary cultures of ovine hepatocytes were grown in defined media. In a first experiment the media contained various fractions (0.2, 1.0, 5.0) of portal vein amino acid concentrations in fed sheep. In the second 24h incubation period, unstimulated IGF-I secretion was highly sensitive the concentration of amino acids in the media, with significantly greater release of basal IGF-I in 5x compared to either 1x (P<0.05) or 0.2x amino acid containing media. In a second series of experiments the effects of specific amino acid depletions was examined. Methionine depletion of 0.2x portal amino acid concentrations ablated the GH response second 24h of culture without affecting basal IGF-I release. By comparison 3H-leucine incorporation into secreted protein, following 20 hours of culture in defined media was significantly reduced in 0.2x aa (P<0.01) and 1.0x aa (P<0.05) media compared with 5.0x aa media, however secretory protein synthesis was unaffected by methionine depletion to 0.2x portal concentrations. The results suggest that amino acid availability regulates both basal and GH stimulated IGF-I release in ovine hepatocytes. Furthermore reducing methionine concentrations in the culture media to 0.2x portal concentrations diminishes GH response without compromising protein secretion.
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11

Santos, Valdinei Moreira dos. "Agrochemicals on growth and hormonal relations of \'Micro-Tom\' and Arabidopsis roots under water deficit conditions." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11144/tde-06012017-171318/.

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The increasing concerns launched by debates about climate changes added to the uncontrolled growth of world population have opened a market to natural inputs for a more sustainable agriculture. Taking those concerns together, it is very important to think in advance in terms of finding solutions to increase the food production, with improved quality and in a supposed changing environment. Natural substances such as seaweed biostimulants are coming up as inputs for crops yield and abiotic stress tolerance enhancement with increasing use in agriculture. In this scene, it is important to understand effects and mode of action of these substances on plant physiology to permit the development of consistent products and guarantee the delivery of solutions to growers that assist them in solving their needs. Therefore, this research was carried out aiming to understand the role of agrochemicals (classical plant growth regulators and seaweed biostimulants) on root development and hormonal relations of tomato \'Micro-Tom\' and Arabidopsis under water deficit conditions. Ascophyllum nodosum extracts (ANE) ability to stimulate endogenous hormonal responses in conditions of drought and osmotic stress was tested. We carried out experiments with two plant models: one is classically used in plant science studies and the other, a crop-like plant model whose scientific findings can be applied for several crops. We used tomato hormonal mutants and reporter lines grown in conditions of drought stress to study the effects of plant growth regulators and seaweed extracts on root growth and hormonal responses, respectively. Additionally, we tested in vitro the effects of these substances on root growth of Arabidopsis seedlings under osmotic stress conditions. The root development of tomato and Arabidopsis was negatively affected by the presence of water deficit caused by drought and osmotic stress, respectively. Gibberellins biosynthesis inhibitors only affected the root growth of gibberellin-deficient mutant (gib-3). Extracts of the same seaweed presented different effects on root growth of Arabidopsis seedlings and hormonal responsiveness in roots of tomato, possibly due to variability in their compositions. ANE A and B show opposite effects on root growth. ANE A promotes root growth, whereas ANE B shows inhibitory effects. These substances seem to have little influence on auxin responses in roots, however, they alter the balance between abscisic acid and ethylene under drought conditions. The standardization of the composition of seaweed extracts complemented with studies on their physiological and molecular effects in crops is crucial for the establishment of these agricultural inputs as one of the solutions for current and future requirements of food production.
As crescentes preocupações oriundas a partir dos atuais debates sobre mudanças climáticas somadas ao descontrolado crescimento da população mundial têm dado espaço para o uso de insumos agrícolas naturais, objetivando sustentabilidade na agricultura. Diante de tais preocupações, é importante pensar antecipadamente e encontrar maneiras de aumentar a produção e a qualidade de alimentos, em um ambiente de supostas mudanças climáticas. Substâncias naturais, como bioestimulantes à base de alga, estão ganhando relevância como melhoradores da produtividade e tolerância a estresses abióticos com crescentes usos na agricultura. Diante desse cenário, é importante compreender os efeitos e modos de ação dessas substâncias na fisiologia das plantas para permitir o desenvolvimento de produtos consistentes e garantir aos produtores soluções que atendam às suas necessidades. Portanto, este estudo foi realizado com o objetivo de entender o papel de agroquímicos (reguladores vegetais clássicos e biostimulantes à base da alga) sobre o desenvolvimento radicular e relações hormonais do tomateiro \'Micro-Tom\' e Arabidopsis sob condições de estresse hídrico. Foi testada a habilidade de extratos Ascophyllum nodosum (ANE) em estimular respostas hormonais em condições de seca e estresse osmótico. Foram realizados experimentos com duas plantas-modelo: Arabidopsis que é largamente utilizada em estudos científicos de plantas e o tomateiro \'Micro-Tom\', uma planta-modelo mais adequada para estudos aplicados à agricultura sob condições tropicais. Foram utilizados mutantes hormonais e linhas-repórter de tomate cultivadas em condições de seca para o estudo dos efeitos dos reguladores vegetias e extratos de alga no crescimento radicular e respostas hormonais, respectivamente. Além disso, foram testados in vitro os efeitos dessas substâncias no crescimento radicular de plântulas de Arabidopsis em condições de estresse osmótico. O desenvolvimento radicular do tomateiro e Arabidopsis foi negativamente afetado pela ocorrência do déficit hídrico causado por seca e estresse osmótico, respectivamente. Inibidores de giberelinas afetaram apenas o crescimento radicular do mutante com baixo nível endógeno giberelinas (gib-3). Extratos da mesma espécie de alga apresentaram diferentes efeitos no crescimento radicular de plântulas de Arabidopsis e resposta hormonal em raízes de tomateiro. ANE A e B aprensenta efeitos opostos no desenvolvimento de raízes. ANE A promove o crescimento radicular enquanto ANE A inibe. ANEs pouco influenciam as respostas auxínicas, contudo, essas substâncias alteram o balanço entre entre ácido abscísico e etileno sob condições de estresse hídrico por seca. A padronização da composição de extratos de alga somada aos estudos sobre os seus efeitos fisiológicos e moleculares em culturas é crucial para o estabelecimento desses insumos agrícolas como uma das soluções para as necessidades atuais e futuras da produção de alimentos.
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12

Binder, Bradley Fletcher. "The chemistry and biology of insect growth regulators from plants in the genus Nama (Hydrophyllaceae)." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184795.

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A strategy for the discovery of new insect growth regulators from arid lands plants was developed. Plant genera with a history of toxicity, medicinal use, or incorporation in native american cultures were selected. Forty-five species from twenty-one families were collected, extracted, and tested for biological activity on the large milkweed bug, Oncopeltus fasciatus. Eight extracts were toxic and the extract of Nama hispidum (Hydrophyllaceae) caused nymphs to undergo precocious metamorphosis to an adult. The active component of N. hispidum was precocene II (6,7-dimethoxy-2,2-dimethyl chromene). Nine Nama species, representing four of the five sections in the genus were gathered from Hawaii, California, Nevada, Arizona, New Mexico, and the Dominican Republic. In addition to the insect anti-hormone, precocene II (PII), present in N. hispidum, N. rothrockii contained at least two different insect juvenile hormone mimics, and N. sandwicense contained insect anti-hormone and insect juvenile hormone mimics. Fifth instar larvae of Heliothis zea were used as model insects to distinguish between post-ingestive intoxication and feeding deterrency during exposure to PII. Larvae fed artificial diet with PII were deterred from eating, and had retarded weight gain, growth, and development. Insects grown on diet with PII consumed less food, could not digest the food, or convert ingested food to body mass. in vivo radiotracer studies with the nutrient, ¹⁴C linoleic acid, show a lower rate of transport and incorporation of radioactivity into fat body tissue. A change in the midgut epithelial cells from PII resulted in reduced transport efficiency and retarded larval growth and development. Scanning electron microscopy of the midgut epithelia indicated that cytotoxic damage is induced by PII. Observed changes in the midgut epithelial cells are consistent with a destructive alkylation of cell structures by PII.
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13

Mendes, Luciane de Siqueira. "Efeitos de ethephon e giberelina no desenvolvimento inicial e em alguns parâmetros tecnológicos da cana-de-açúcar." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/11/11144/tde-11022011-090813/.

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A cana-de-açúcar é uma das principais e dos mais antigos cultivos do Brasil, ocupando lugar de destaque na economia do país devido à produção de açúcar e etanol. Atualmente, São Paulo é o principal estado produtor, impulsionando a economia brasileira devido as suas grandes áreas plantadas. O uso de reguladores vegetais vem se tornando uma prática rotineira, objetivando maximizar o potencial produtivo das culturas, promovendo melhorias na qualidade, otimizando os resultados agroindustriais e econômicos. Giberelina é um hormônio conhecido como promotor de crescimento e alongamento das plantas. O ethephon é um maturador vegetal muito utilizado na cultura da cana, promovendo a liberação de etileno quando em contato com o tecido vegetal. O objetivo do trabalho foi estudar a eficácia dos reguladores vegetais giberelina (GA) e ethephon (CEPA) aplicados em diferentes fases do desenvolvimento inicial, na morfologia e aspectos tecnológicos da cana-de-açúcar. Para isso foram efetuados quatro experimentos. As concentrações aplicadas de GA (0; 10; 25; 50 e 75 mg L-1) e CEPA (0; 225; 450; 900 e 1000 mg L-1), foram iguais nos dois primeiros experimentos. O primeiro experimento foi realizado no Horto Experimental do Departamento de Ciências Biológicas da ESALQ/USP, com a pulverização dos toletes, com dez repetições e o segundo foi realizado na Estação Experimental da Syngenta em Holambra com a pulverização de plantas jovens (na soqueira), com quatro repetições, sendo que os parâmetros biométricos foram avaliados quinzenalmente até aos 90 dias após o plantio (DAP). O terceiro experimento foi efetuado em casa de vegetação no Horto Experimental do Departamento de Ciências Biológicas da ESALQ/USP, sendo que para a avaliação dos parâmetros tecnológicos no início do desenvolvimento, pulverizaram-se toletes com GA 50 mg L-1 e CEPA 900 mg L-1 além do controle, utilizando-se de cinco repetições. As amostras foram coletadas e congeladas, para posteriores análises tecnológicas. No quarto experimento, avaliou-se a aplicação dos reguladores vegetais in vitro, onde se aplicou GA (0; 2,5; 5,0; 7,5 e 10 mg L-1) e CEPA (0; 25; 50; 100; 200 mg L-1), com 5 repetições. Os resultados foram submetidos a análise de variância pelo teste F, e comparados pelo teste de Tukey à 5% de probabilidade. No primeiro experimento, a aplicação de GA nos toletes reduziu de forma geral o desenvovimento inicial das plantas, enquanto os tratamentos com CEPA apresentaram resultados promissores ao desenvolvimento inicial, quando os parâmetros avaliados foram os perfilhos. No segundo experimento, a aplicação de GA em soqueira aumentou a altura da planta, sendo que CEPA retardou a altura das plantas e incrementou o número de perfilhos. No terceiro experimento, nas avaliações tecnológicas, GA e CEPA afetaram temporariamente os teores de açúcares totais produzidos nas folhas. No colmo, CEPA e GA afetaram de forma geral os parâmetros tecnológicos, reduzindo as atividades das invertases e os açúcares redutores e totais e No quarto experimento, a aplicação in vitro de GA, reduziu o número de perfilhos, enquanto aplicação de CEPA incrementou o número de perfilhos e reduziu a altura das plantas.
Sugarcane is one of the major and oldest crops in Brazil, taking a prominent place in the economy because of the production of sugar and ethanol. Currently, Sao Paulo is the main producing state, boosting the Brazilian economy due to its large planted areas. The use of plant regulators has become a routine practice, aiming to maximize the yield potential of crops, improving quality, optimizing results for the agroindustry and economy. Gibberellin is a plant hormone known as a regulator of plant growth and elongation. Ethephon is a growth regulator widely used in maturing sugarcane cultivation, allowing the release of ethylene when in contact with the plant tissue. This work aimed to evaluate the effectiveness of plant regulators gibberellin (GA) and ethephon (CEPA), applied at different stages of early development, on the morphology and technological aspects of sugarcane. To that end, four experiments were performed. The concentrations of GA (0; 10; 25; 50 and 75 mg L-1) and CEPA (0; 225; 450; 900 and 1000 mg L-1), were equal in the first two experiments. The first experiment was conducted in the Experimental Garden of the Department of Biological Sciences, ESALQ / USP, by spraying of cuttings, with ten repetitions. The second was conducted at Syngenta\'s experimental station in Holambra, by spraying the young plants (at stumps) with four replicates, and biometric parameters were measured fortnightly until 90 days after planting (DAP). The third experiment was conducted in a greenhouse at the Experimental Garden of the Department of Biological Sciences, ESALQ / USP, and for the evaluation of technological parameters in early development, cuttings were sprayed with GA 50 mg L-1 and CEPA 900 mg L-1 besides the control, using five replicates. Samples were collected and frozen for later technological analysis. In the fourth experiment, the application of plant regulators in vitro was evaluated, where GA (0; 2.5; 5.0; 7.5 and 10 mg L-1) and CEPA (0; 25; 50; 100; 200 mg L-1) were applied with five replicates. The results were submitted to variance analysis by F test and compared by Tukey test at 5% probability. In the first experiment, the application of GA reduced, in general terms, the initial development of plants whereas treatments with CEPA had promising results in early development, regarding the tillering. In the second experiment, the application of GA increased plant height, while the CEPA retarded plant height and increased the number of tillers. In the third experiment in technological assessments, GA and CEPA temporarily affected the contents of total sugars in the leaves. In the stem, GA and CEPA affected, in general, technological parameters, reducing the activities of invertase as well as those of the reducing and total sugars. In the fourth experiment, the application of GA in vitro decreased the number of tillers, while the treatment with CEPA increased the number of tillers and delayed the plant height.
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14

Wippermann, Barbara. "Functional characterisation of the TCTP gene : a role in regulation of organ growth." Thesis, Lyon, École normale supérieure, 2013. http://www.theses.fr/2013ENSL0814.

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La croissance d’un organisme multicellulaire pour atteindre une taille bien définie, nécessite une coordination de la prolifération cellulaire, de l’expansion et de la différentiation cellulaire ainsi que de la mort cellulaire. Ces processus sont sous l’influence de l’état nutritionnel de l’organisme, les conditions de son environnement et des signaux hormonaux. Translationally controlled tumor protein (TCTP) est un facteur essentiel à la croissance des plantes et des animaux. La protéine TCTP de plante contrôle la croissance mitotique, tandis que la protéine TCTP animale contrôle la croissance mitotique et post-mitotique. Une voie importante dans la régulation de la croissance en réponse aux nutriments est la voie Target of Rapamycin (TOR). Chez la Drosophile, il a été montré que dTCTP serait un régulateur positif en amont de TOR. Au cours de ma thèse, j’ai étudié le lien entre TCTP et la voie TOR, afin de savoir si, comme chez les animaux, AtTCTP agit en amont de la voie TOR pour contrôler la croissance des organes. Afin de savoir si la voie TCTP était liée à l’état nutritionnel, j’ai recherché l’impact du milieu de culture sur la létalité de la mutation tctp. J’ai ensuite caractérisé l’impact de la mutation tctp sur le transport et l’homéostasie de l’hormone auxine. J’ai enfin analysé pourquoi TCTP de plante ne contrôle pas la croissance post-mitotique par expansion cellulaire, contrairement à TCTP animale. Les données de la littérature montrent que chez les animaux TCTP est un activateur positif en amont de la voie TOR. Chez la plante Arabidopsis thaliana, mes données d’interactions génétiques sont en faveur d’un modèle dans lequel AtTCTP agit indépendamment de la voie TOR, contrairement de ce qu’il a été proposé chez les animaux. Chez les plantes, la perte de fonction de TCTP est associée à un retard du développement embryonnaire et à la mort. Cette létalité peut être complémentée par sauvetage des embryons sur du milieu riche en nutriments. J’ai montré que l’ajout de sucrose ou de glutamine dans le milieu de sauvetage des embryons tctp est nécessaire à leur développement. Ces données suggèrent qu’in vitro, AtTCTP n’est pas nécessaire à l’approvisionnement et à l’utilisation des nutriments sucrose, glucose ou glutamine. Dans leur ensemble, ces résultats réévaluent le rôle du régulateur de croissance TCTP en montrant que le gène AtTCTP régule la croissance mitotique indépendamment de la voie TOR et des voies de signalisation liées aux nutriments. L’observation des flux d’auxine en suivant la localisation de PIN1-GFP dans les embryons et les inflorescences du mutant tctp ne montre aucune altération par rapport au phénotype sauvage. De même, l’homeostasie de l’auxine, suivie à l’aide du rapporteur DR5::GFP n’est pas altérée dans les embryons tctp. Ceci suggère que le défaut de croissance du mutant tctp n’est pas lié à une altération du flux ou de l’homéostasie de l’auxine. La protéine TCTP de plante ne contrôle pas la croissance post-mitotique, contrairement à la protéine TCTP animale. J’ai réalisé un échange de domaines protéiques entre AtTCTP et Drosophila dTCTP. Le but était d’identifier les domaines protéiques de la protéine TCTP animale qui permettent la croissance post-mitotique. La plupart des protéines chimères étaient instables dans la Drosophile. Afin de comprendre pourquoi, j’ai réalisé du modelage par homologie et j’ai discuté la structure des chimères dans ma thèse.L’ensemble de mes résultats permet de mieux comprendre la fonction de TCTP chez les végétaux, en montrant que cette fonction s’exerce indépendamment de la voie TOR
The growth of a multicellular organism and its size determination require the tight regulation of cell proliferation, cell differentiation, cell growth and apoptosis. These processes are influenced by the nutritional state of the organism, its environmental conditions and hormonal signals. Translationally controlled tumor protein (TCTP) is an essential regulator of growth in plants and animals. In plants it controls mitotic growth, whereas in animals, it controls mitotic and post-mitotic growth. One of the important pathways involved in the control of growth in response to nutrients is the Target of Rapamycin (TOR) pathway. In Drosophila, dTCTP was proposed to act a positive regulator upstream of TOR, although this role remains a matter of debate in the animal field.During the past 3 years of my PhD. thesis, I addressed the question whether plant TCTP acts upstream of TOR to control organ growth. I studied the impact of nutrient availability and hormones on TCTP role to control growth in plants and vice versa. Finally, I examined why plant TCTP does not control post-mitotic cell expansion growth, conversely to animal TCTP using a structure-function approach.In animals, TCTP was proposed to act as a positive activator upstream of the TOR pathway. In plants, my data support a model in which AtTCTP acts independently from the plant TOR pathway, thus in contrast to what has been proposed in animals. TCTP loss of function leads to delay of embryo development and death. Nutrient supplement rescues this embryos lethality. First, I demonstrate that embryos grown on nutrients lacking sucrose or glutamine fail to develop correctly. My data demonstrate that in vitro AtTCTP is not essential to the uptake, the use of and the response to the nutrients glucose, sucrose or glutamine. Taken together, these results reevaluate the role of AtTCTP as a growth regulator controlling mitotic growth independently from the TOR pathway and likely from nutrient related signaling pathways. Interestingly, my data also show that AtTCTP controls growth independently from auxin flux or homeostasis and that auxin-induced growth can occur without TCTP. To address why plant TCTP do not control post-mitotic growth conversely to animal counterpart, I performed protein domain swaps and created chimera proteins between Arabidopsis AtTCTP and Drosophila dTCTP. The rational was to identify protein domains that differentiate plant and animal TCTPs with regard to post-mitotic growth control. Most of chimera proteins were instable and I was unable to complement tctp loss of function in Drosophila. I performed a structure based modeling to understand this phenotype and the outcome is discussed in my PhD thesis.Altogether my results improve the understanding of plant morphogenesis by reevaluating the role of the central growth regulator TCTP
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15

Monteiro, Giselle Gomes. "Desenvolvimento de micorrizas arbusculares em mutantes hormonais de tomateiro (Lycopersicon esculentum cv Micro-Tom)." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11138/tde-17032011-104351/.

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Os hormônios vegetais etileno e ABA são possíveis reguladores chave do desenvolvimento das micorrizas arbusculares (MAs). O primeiro objetivo deste trabalho foi avaliar o desenvolvimento da MA em mutantes superprodutores e insensíveis ao etileno (epinastic e Never ripe, respectivamente) e verificar se enzimas relacionadas ao sistema de defesa vegetal são reguladas diferencialmente pelo etileno durante o desenvolvimento da simbiose A colonização de raízes de epinastic (epi) por G. clarum foi significativamente reduzida quando comparada com Micro-Tom (MT), além disso, a funcionalidade da simbiose, demonstrada pelo acúmulo de transcritos de LePT4, foi fortemente reduzida quando comparada com MT. Por outro lado, o padrão de colonização e funcionalidade da simbiose no mutante Nr não diferiu de MT. Indução no acúmulo de transcritos de genes que codificam quitinases e enzimas relacionadas ao estresse oxidativo foi observada no mutante epi, enquanto o acúmulo de transcritos de uma -1,3-glucanase foi fortemente induzido no mutante Nr. O segundo objetivo foi verificar se a colonização reduzida observada em mutantes deficientes em ABA é dependente da produção do etileno. Para tanto, mutantes que diferem na deficiência de ABA e produzem diferentes quantidades de etileno (notabilis e sitiens) e o mutante epi foram inoculados com G. clarum e tratados com aminoethoxivinilglicina (AVG), um inibidor de etileno. A colonização intrarradicular de G. clarum nos mutantes epi e notabilis (not) foi significativamente reduzida quando comparada com MT, sendo que o mutante sitiens (sit) foi o menos susceptível à colonização em relação aos demais genótipos. A aplicação de AVG a 10 µM restaurou completamente a colonização em epi, mas não nos mutantes deficientes em ABA. O acúmulo de transcritos de LePT4 confirmou os resultados de colonização. Os genes que codificam enzimas chave na biossíntese do etileno, LeACS2 e LeACO4, foram regulados positivamente pela inoculação com G. clarum, e a restauração do desenvolvimento da MA observada em epi que recebeu AVG, provavelmente envolveu ACC oxidase (LeACO4). O acúmulo de transcritos dos genes que codificam ACC oxidase (LeACO1 e LeACO4) foi induzido significativamente em sit, mostrando que a superprodução de etileno observada neste mutante pode envolver a regulação da ACC oxidase. Por fim, indução no acúmulo de transcritos do gene LeNCED foi observada em todos os genótipos micorrizados e em raízes de epi que receberam AVG, demonstrando que LeNCED é regulado positivamente pela inoculação com G. clarum e que o etileno regula a expressão deste gene. Os resultados demonstram que etileno e ABA estão envolvidos na regulação do desenvolvimento de MA e que etileno modula a expressão de genes relacionados ao sistema de defesa vegetal permitindo o estabelecimento de uma simbiose funcional.
The plant hormones ethylene and ABA are probably key developmental regulators of arbuscular mycorrhizae (AM). The first objective of this work was to evaluate the development of MA in overproducing and insensitive mutants to ethylene (epinastic and Never ripe, respectively) and verify if enzymes related to plant defense system are differentially regulated by ethylene during the symbiosis development. The colonization of epinastic (epi) roots by G. clarum was significantly reduced when compared with Micro-Tom (MT), moreover, the functionality of the symbiosis as demonstrated by transcripts accumulation of LePT4, was strongly reduced when compared with MT. Still, the pattern of colonization and functionality of the symbiosis in the Nr mutant did not differ from MT. Induction in the transcripts accumulation of genes encoding chitinase and enzymes related to oxidative stress was observed in epi mutant, whereas transcripts accumulation of -1, 3-glucanase was strongly induced in the Nr mutant. The second objective was to determine whether the reduced colonization observed in mutants deficient in ABA is dependent on ethylene production. For this purpose, mutants that differ in ABA deficiency and produce different amounts of ethylene (notabilis and sitiens) and the epi mutant were inoculated with G. clarum and treated with an ethylene inhibitor called aminoethoxivinilglicin (AVG). The intraradical colonization of G. clarum in epi and notabilis (not) mutants was significantly reduced when compared with MT and sitiens mutant was less susceptible to colonization in comparison with other genotypes. The application of AVG to 10 µM completely restored the colonization in the epi but not in mutants deficient in ABA. The transcripts accumulation of LePT4 confirmed the results of colonization. The genes that encode key enzymes in the biosynthesis of ethylene, LeACS2 and LeACO4, were positively regulated by inoculation with G. clarum and the restoration in the development of MA observed in epi which received AVG probably involved ACC oxidase (LeACO4). Transcripts accumulation of genes that encode ACC oxidase (LeACO1 and LeACO4) were induced significantly in sit showing that overproduction of ethylene in this mutant can involve ACC oxidase. Finally, the induction in the accumulation of gene transcripts LeNCED was observed in all genotypes and mycorrhizal roots of epi which received AVG demonstrating that LeNCED is regulated positively by the inoculation with G. clarum and that ethylene regulates the expression of this gene. Results show that ethylene and ABA are involved in regulating of MA development and ethylene modulates the expression of genes related to the plant defense system allowing the establishment and functionality of the symbiosis.
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16

Truskina, Jekaterina. "The role of auxin in cell differentiation in meristems." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEN033/document.

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L'auxine régule la croissance et le développement des plantes grâce aux facteurs de transcription de la famille des "AUXIN RESPONSE FACTOR" (ARF). Chez Arabidopsis thaliana en particulier, ARF5, 6, 7, 8 et 19 activent l'expression de gènes cibles en réponse à l'auxine. Ces cinq ARF activateurs contrôlent de façon plus ou moins redondante des processus divers au cours du développement de la plante, notamment la régulation des croissances au niveau des méristèmes racinaires et aériens ainsi que la formation des racines latérales ou des méristèmes axillaires.Chacun de ces cinq ARF activateurs présente des patrons d'expression uniques dans chacun des tissus racinaires et aériens, en association avec leurs fonctions particulières. Il est probable que cette expression tissu-spécifique trouve son origine dans un contrôle différencié de leur transcription. Dans cette étude, des régulateurs amonts de la transcription de ARF5, 6, 7, 8 et 19 ont été identifiés par une méthode haut-débit de crible simple hybride en levure (Y1H). Une procédure d'expression transitoire en protoplastes a permis de confirmer que l'expression de chaque ARF activateur est contrôlée par des régulateurs spécifiques, dont la majorité se comportent comme des répresseurs de la transcription des ARF in planta. Parmi les régulateurs identifiés, les facteurs de transcription ont été étudiés grâce à des mutants pour préciser les interactions in planta. Ces mutants montrent des phénotypes développementaux typiques de perturbations de l'auxine dans les racines et les tiges : altérations des cinétiques de croissance, de l'émergence des organes latéraux ou de réponses à l'auxine et modification de l'expression des ARF activateurs.Par ailleurs, ce travail aborde également les dialogues entre les voies de signalisation de l'auxine et des cytokinines, et en particulier le rôle de ces interactions dans le développement des racines et des tiges. Une des interactions identifiées dans le crible Y1H est la répression de ARF7 par CRF10, un gène membre de la famille des "Cytokinin Response Factors". Nous avons mis en évidence l'importance de cette interaction pour le maintien de l'architecture du méristème apical racinaire, pour la sénescence des feuille et pour la réponse phototropique à la lumière bleue dans les hypocotyles
Auxin regulates plant growth and development through the transcription factors of the AUXIN RESPONSE FACTOR (ARF) gene family. Most notably in Arabidopsis thaliana ARF5, 6, 7, 8 and 19 activate expression of target genes in response to auxin. These five ARF activators control both variable and overlapping processes during plant development including regulation of growth at the root and the shoot apical meristems, lateral root and axillary shoot formation. Each of the five ARF activators shows unique tissue-specific expression patterns in the root and the shoot associated with their distinct functions. This tissue-specific expression is likely derived from the differences in the control of ARF activator transcription. In this study the upstream regulators of ARF5, 6, 7, 8 and 19 transcription were identified. This was achieved by utilizing a high-throughput yeast one-hybrid (Y1H) method. The transient protoplast assay revealed that each ARF activator is controlled by specific transcriptional regulators and that the majority of these regulators are repressors of ARF transcription in planta. Mutants of the regulatory transcription factors were utilized to additionally investigate the interactions in planta. These mutants display auxin-related developmental phenotypes in the root and the shoot including alternations in growth kinetics, emergence of lateral organs, responses to auxin and altered expression of ARF activators. Furthermore, this study additionally focuses on cross-talk between the auxin and cytokinin signaling pathways and its role in root and shoot development. One of the interactions identified in the Y1H screen is a repression of ARF7 by CRF10, a member of the Cytokinin Response Factors gene family. The importance of this interaction in maintaining architecture of the root apical meristem, in leaf senescence and in the phototropic response to blue light in hypocotyls is studied
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17

Puga, Freitas Ruben. "Effet du ver de terre Aporrectodea caliginosa sur la croissance des plantes, leur développement et leur résistance aux pathogènes : réponse physiologique et moléculaire de la plante à l'émission de molécules-signal." Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1158/document.

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Les plantes se développent et évoluent en interaction avec les organismes du sol. L'impact des vers de terre sur la croissance des plantes, généralement positif, a été attribué à des modifications physiques, chimiques ou biochimiques du sol, souvent sans démonstration rigoureuse. Dans ce travail, les techniques développées en sciences du végétal (culture in vitro, utilisation de mutants et transcriptomique) ont été utilisées afin de comprendre les mécanismes à l'origine de l'effet des vers de terre sur les plantes. Nos résultats apportent de nouvelles connaissances fondamentales: (1) la production de molécules-signal à l'intérieur des déjections de vers de terre a un impact significatif sur la croissance d'Oryza sativa et Lolium perenne. (2) Ces molécules agissent sur la voie de signalisation fortement liée à l'auxine, comme suggéré par l'effet significatif du ver de terre sur la croissance du double mutant d'A. thaliana aux1-7;axr4-2. (3) L'abondance de ces molécules-signal en présence de vers de terre pourrait être liée à la stimulation de certaines populations bactériennes capables de synthétiser de l'auxine. (4) Le ver de terre induit une accumulation de transcrits pour des gènes sous contrôle de l'acide jasmonique et de l'éthylène. Ces hormones sont notamment impliquées dans un mécanisme de résistance systémique induite (ISR), connu pour être induit par certaines rhizobactéries promotrices de la croissance des plantes. Enfin, (5) le piétin échaudage, maladie due à un champignon pathogène, déclenche chez le blé (Triticum aestivum) une réaction d'hypersensibilité et une modification de la signalisation hormonale, qui sont considérées comme des mécanismes de contrôle du métabolisme de la plante qui facilitent l'infection du pathogène. La sévérité de cette maladie est réduite en présence de vers de terre. La synthèse de ces résultats indique que les vers de terre, comme d'autres organismes du sol, modifient l'équilibre hormonal de la plante. L'homéostasie hormonale apparaît comme un élément incontournable pour prédire l'issue des interactions multiples que les plantes entretiennent avec les organismes du sol
Plants develop and evolve in interaction with soil organisms. The impact of earthworms, likely positive, has been attributed to modifications of physical, chemical or biochemical soil properties, without rigorous demonstration. In this work, techniques developed in plant science (in vitro culture, use of mutant plants and trancriptomic analysis) were used to understand the mechanism involved in the effect of earthworms on plants. Our results bring new fundamental knowledge: (1) production of signal-molecules within earthworm dejections has a positive impact on the growth of Oryza sativa and Lolium perenne. (2) These molecules act on auxin signaling, as suggested by the positive impact of the earthworm on the growth of A. thaliana double mutant aux1-7;axr4-2. (3) The abundance of these signal-molecules in presence of the earthworms could be related to the stimulation of bacterial communities able to produce auxin. (4) Earthworms induce an accumulation of gene transcripts known to be under control of jasmonic acid and ethylene. These two hormones are most notably involved in the defense mechanism called induced systemic resistance (ISR), known to be induced by plant growth promoting rhizobacteria. Finally, (5) Take-all disease, due to a pathogenic fungus, induced in wheat (Triticum aestivum) a hypersensitive response and a modification on hormone signaling, which are known as manipulations of plant metabolism in a way that facilitates pathogen infection. The severity of take-all disease was alleviated in the presence of earthworms. Synthesis of these results showed that earthworms, like other soil organisms, modify the hormone balance in the plant. Hormone homeostasis appeared to be an important element to predict the issue of the multiple interactions that plants established with soil organisms
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18

Perazza, Daniel. "Les hormones gibberellines et les gènes kaktus controlent les endoréplications dans les trichomes d'Arabidopsis thaliana." Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10058.

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Au terme d'une recherche de mutants affectes dans la reponse aux phytohormones gibberellines (ga) chez arabidopsis thaliana, une nouvelle fonction des ga dans la formation des trichomes et le controle des endoreplications a ete mise en evidence. Les trichomes foliaires sont des cellules epidermiques specialisees a trois branches qui demandent 4 endoreplications, ammenant l'adn nucleaire de 2c a 32c. Le developpement des trichomes est un modele pour l'etude de la specification et de la differenciation cellulaire chez les plantes. Chez le mutant gal-3, deficient dans la biosynthese des ga, les trichomes ne se developpent pas et les cellules epidermiques subissent moins d'endoreplications. Au contraire, le mutant spy-5, chez qui la reponse aux ga est activee, developpe des trichomes a branches surnumeraires ayant subi une endoreplication supplementaire (64c). La surexpression du facteur de transcription gl1 (de type myb) restaure la formation des trichomes et la polysomatie de l'epiderme chez le mutant gal-3, demontrant que les ga controlent ces processus via gl1. L'activation de gl1 est transcriptionnelle puisque le gene rapporteur gusa place sous le controle du promoteur pgl1 ne s'exprime qu'en presence de ga. Par contre, le facteur de transcription ttg, aussi implique dans l'initiation des trichomes, semble present chez les plantes gal-3. Les gibberellines controlent donc positivement l'initiation et la morphogenese des trichomes, ainsi que le niveau de polysomatie de l'epiderme via le gene gl1. De nouveaux mutants kaktus developpant des trichomes a branches surnumeraires ont ete isoles a partir d'une collection de graines d'arabidopsis traitees a l'ems. Le contenu en adn de ces trichomes mutants est de 64c, ce qui montre qu'ils ont subi une endoreplication supplementaire. La polysomatie des cellules foliaires des couches internes n'est pas alteree, ce qui indique que les genes kak sont specifiques des cellules epidermiques, voire des seuls trichomes. Les sept mutants kak etudies definissent au moins trois loci independants et deux d'entre eux ont ete cartographies. L'additivite de phenotype entre certaines mutations kak ainsi que l'additivite observee chez les doubles mutants kak,try indiquent l'existence d'au moins trois voies independantes d'inhibition d'une cinquieme endoreplication. Chacune de ces voies est dependante du gene gl3.
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19

Childerhouse, Emma. "The effect of a natural plant extract and synthetic plant growth regulators on growth, quality and endogenous hormones of Actinidia chinensis and Actinidia deliciosa fruit : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Horticultural Science at Massey University, New Zealand." Massey University, 2009. http://hdl.handle.net/10179/1052.

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Kiwifruit are of huge economic importance for New Zealand representing 29 percent of total horticultural exports. Fruit size is the biggest determinant of what consumers are willing to pay, and there is also a positive relationship between consumer preference for flavour and percentage dry matter. The two main cultivars exported from New Zealand are Actinidia chinensis ‘Hort 16A’ (gold kiwifruit) and A. deliciosa ‘Hayward’ (green kiwifruit). Under current commercial practice the only product allowed for use on kiwifruit to increase fruit size in New Zealand is Benefit®. Benefit® has been shown to induce different results when applied to A. chinensis and A. deliciosa, whereas synthetic plant growth regulators such as the cytokinin-like substance N-(2- chloro-4-pyridyl)-N’-phenylurea (CPPU) have been found to promote similar increases in fresh weight of fruit in both cultivars. Final fruit size is determined by both cell division and cell enlargement. It was been shown that fresh weight can be increased in both of the major Actinidia cultivars even though their physiology differs. Hormonal control of fruit size in relation to cell division and cell enlargement phases of fruit growth was studied in both A. chinensis and A. deliciosa. CPPU was applied to both cultivars in a growth response experiment where fruit were collected throughout the growing season. The objective of this experiment was to create growth curves, to compare and contrast the effect on A. chinensis and A. deliciosa, and to provide material for hormone analysis. Application of CPPU was found to significantly increase the fresh weight of both A. chinensis and A. deliciosa fruit (46.98 and 31.34 g increases respectively), and alter the ratio of inner and outer pericarps of A. chinensis fruit. CPPU and Benefit® were applied individually and together to both cultivars. It was found that only A. chinesis fruit were affected by the application of Benefit®; fresh weight was increased by 26.38 g, and percentage dry matter was significantly reduced. There was a statistically significant (p < 0.05) interaction between CPPU and Benefit® when applied to A. chinensis. 3,5,6-trichloro-2-pyridyloxyacetic acid (3,5,6-TPA) was applied to A. deliciosa on two application dates at three concentrations and was found to decrease fresh weight of fruit, but significantly increase percentage dry matter regardless of application date or concentration. Lastly CPPU and 1-naphthalene acetic acid (NAA) were applied to A. deliciosa at two application dates and in all combinations. Application date affected the response to both a low concentration of CPPU and NAA. A synergistic interaction was observed when CPPU was applied early plus NAA late (CPPU early (4.53 g increase) plus NAA late (13.29 g) < CPPU early plus NAA late (33.85 g). Finally endogenous hormone content was studied. Methods were developed and tested for the simultaneous analysis of both indole-3-acetic acid (IAA) and cytokinins. Freeze dried fruit were purified using Waters Sep-pak® cartridges and Oasis® columns then IAA was quantified by high pressure liquid chromatography. Preliminary results indicate a correlation between application of CPPU and endogenous IAA, high concentrations of IAA correlated well with periods of rapid fruit growth particularly for CPPU treated fruit.
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20

Pinto, Junior Artur Soares. "Doses de inoculante e estirpes de Azospirillum brasilense associadas à adubação nitrogenada na cultura do milho." Universidade Estadual do Oeste do Paraná, 2013. http://tede.unioeste.br:8080/tede/handle/tede/1448.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
This study aimed to evaluate under field conditions in different areas of southern Brazil, the effect associated with mineral fertilizers and different dosages of inoculant formulated from the strains Ab-V5, V6 and Ab-Ab-V7 of Azospirillum brasilense. The experimental design was randomized blocks with four blocks and ten treatments. The treatments were formed by the doses of 0, 60 and ha-1 of nitrogen without seed inoculation dose to 120 kg and 60 kg ha-1 nitrogen + individual inoculation and associated strains of Ab-V5, V6 and Ab-Ab -V7. Biometric evaluations were performed during the stage of eight mature leaves (V8), as well as assessments of components of production and productivity at the end of the crop cycle. Levels of N, P and K leaves in early female flowering were also evaluated as well, the levels of these nutrients in grains. The results indicate that regardless of the area evaluated, the use of inoculant base of A. brasilense associated with the dose of 60 kg ha-1 of nitrogen results in increases in growth, development and yield of corn
O presente trabalho teve por objetivo avaliar em condições de campo em diferentes áreas do Sul do Brasil, o efeito associado de fertilização mineral e diferentes dosagens de inoculante formulado a partir das estirpes Ab-V5, Ab-V6 e Ab-V7 de Azospirillum brasilense. O delineamento experimental utilizado foi de blocos ao acaso, com quatro blocos e dez tratamentos. Os tratamentos foram formados pelas doses de 0, 60 e 120 Kg ha-1 de nitrogênio, sem inoculação das sementes e a dose de 60 Kg ha-1 de nitrogênio + inoculação individual e associada das estirpes Ab-V5, Ab-V6 e Ab-V7. Foram realizadas avaliações biométricas durante o estádio de oito folhas definitivas (V8), bem como, avaliações dos componentes de produção e da produtividade no final do ciclo da cultura. Também foram avaliados os teores de N, P e K das folhas no início da floração feminina, bem como, os teores desses nutrientes presentes nos grãos. Os resultados obtidos indicam que, indiferente da área avaliada, a utilização de inoculante a base de A. brasilense associado à dose de 60 Kg ha-1 de nitrogênio resulta em incrementos no crescimento, desenvolvimento e produtividade do milho
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21

Lima, Luara Cistina de. "Bioestimulante e fertilizantes foliares no cultivo de Brachiaria híbrida." Universidade Federal de Uberlândia, 2016. https://repositorio.ufu.br/handle/123456789/17854.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Bioestimulantes proporcionam incrementos no desenvolvimento vegetal quando aplicados isolados ou em associação com outros produtos. Todavia poucos estudos abordam aspectos vegetativos e produtivos relacionados à aplicação desses em gramíneas forrageiras. Diante disso, o presente trabalho teve como objetivo o estudo das respostas de gramíneas submetidas à aplicação de Bioestimulantes e fertilização foliar. Instalou-se dois experimentos individuais, utilizando a Brachiaria híbrida Convert HD364, na Fazenda Capim Branco, pertencente à Universidade Federal de Uberlândia. O primeiro experimento foi conduzido em delineamento em blocos casualizados, com seis tratamentos e quatro repetições. Os tratamentos foram doses de bioestimulantes (0,25; 0,5; 0,75; 1,00 e 1,25 L ha-1 em cada aplicação) e a testemunha que constou-se da ausência de aplicação do Bioestimulante. O segundo experimento foi conduzido em delineamento inteiramente casualizados, com 7 tratamentos e 3 repetições. Os tratamentos utilizados foram: testemunha (ausência de adubação), aplicação de 30 Kg ha-1 de N (ureia); 30 Kg ha-1 de N (ureia) + 3,0 L ha-1 de Mastermins® Pastagem; 30 Kg ha-1 de N (ureia) + 3,0 L ha-1 de Starter®; 30 Kg ha-1 de N (ureia) + 0,5 L ha-1 de Bioestimulante; 30 Kg ha-1 de N (ureia) + 3,0 L ha-1 de Mastermins® Pastagem + 0,5 L ha-1 de Bioestimulante; 30 Kg ha-1 de N (ureia) + 3,0 L ha-1 de Starter® + 0,5 L ha-1 de Bioestimulante, aplicados em cada ciclo, após o corte. Para os dois experimentos utilizou-se os tratos culturais recomendados para a Brachiaria híbrida Convert. As avaliações realizadas foram: produção de forragem, valor nutritivo (PB, FDN e FDA), massa de raízes e análise foliar para teores de nutrientes. Realizou-se o teste de Regressão para o primeiro experimento e o teste de Tukey a 0,05 de significância para o segundo experimento. Para o primeiro experimento, concluiu que o bioestimulante promove aumento no acúmulo de MS e na taxa de acúmulo de forragem, folhas e colmos de Brachiaria híbrida, redução no percentual de material morto e na relação de F:C Brachiaria híbrida e não interfere nos teores de N, K, P, Ca, Mg, S, B, Cu, Fe, Mn e Zn, o acúmulo de K, P, Ca, Mg, S, B, Cu, Fe, Mn e Zn, o acúmulo de MS e a taxa de acúmulo de material morto, a densidade de raízes, e percentual de folha e as concentrações de FDA, FDN e PB de Brachiaria híbrida Convert HD364, a partir dos resultados encontrados recomenda-se a dose de 1,25 L ha-1 de bioestimulante para Brachiaria híbrida Convert HD364 e para o segundo experimento, concluiu que Starter N® associado ao bioestimulante e ureia promove maior acúmulo de MS de forragem. Starter N® associado a ureia, Mastermins Pastagens® associado a ureia e bioestimulante e Starter N® associado a ureia e ao bioestimulante promovem aumentos no acúmulo de MS de folhas e de colmos. Starter® associado a ureia, Mastermins Pastagens® associado a ureia, Mastermins Pastagens® associado a ureia e ao bioestimulante e Starter® associado a ureia e ao bioestimulante promove aumento no acúmulo de MS de material morto. Mastermins Pastagens® associado a ureia e ao bioestimulante e Starter® associado a ureia e ao bioestimulante promove aumento na taxa de acúmulo de folha. Starter® associado a ureia, Mastermins Pastagens® associado a ureia e ao bioestimulante e Starter® associado a ureia e ao bioestimulante promove aumento taxa de acúmulo de colmo.
Bioestimulants provide increments in plant development when applied alone or in combination with other products. However, few studies address aspects vegetative and productive, related to the application of these in forage grasses. In addition, the objective of this work was to study the responses of grasses, submitted the application of bioestimulants and fertilization. It was installed two experiments, using the Brachiaria hybrid Convert HD364, on the Capim Branco Farm, belonging to the Federal University of Uberlândia. The first experiment was conducted in randomized blocks with six treatments and four replications. The treatments were doses of biostimulation (0.25; 0.5; 0.75; 1.00 and 1.25 L ha-1 in each application) and the witness who appeared to be the lack of application of bioestimulant. The second experiment was conducted in a completely randomized block design, with seven treatments and three replications. The treatments were: control (absence of fertilization), application of 30 kg ha-1 N (urea); 30 kg ha-1 N (urea) + 3.0 L ha-1 of Mastermins® Pasture; 30 kg ha-1 N (urea) + 3.0 L ha-1 of Starter®; 30 kg ha-1 N (urea) + 0.5 L ha-1 bioestimulant; 30 kg ha-1 N (urea) + 3.0 L ha-1 of Mastermins® Pasture + 0.5 L ha-1 bioestimulant; 30 kg ha-1 N (urea) + 3.0 L ha-1 of Starter® + 0.5 L ha-1 of bioestimulant, applied in each cycle, after the cut. The evaluations were forage production, nutritive value (CP, NDF and ADF), and root mass and leaf analysis for nutrient content. There was a regression testing for the first experiment and the Tukey test at 0.05 significance for the second experiment. For the first experiment, concluded that the bioestimulant promotes an increase in the accumulation of MS and the rate of accumulation of grass, leaves and stems of Brachiaria hybrid, a reduction in the percentage of dead material and in relation to F:C Brachiaria hybrid and does not interfere in the contents of N, K, P, Ca, Mg, S, B, Cu, Fe, Mn and Zn, the accumulation of K, P, Ca, Mg, S, B, Cu, Fe, Mn and Zn, the accumulation of MS and the rate of accumulation of dead material, the density of roots, and percentage of leaf and the concentrations of ADF, NDF and PB, from the results it is recommended that the dose of 1.25 L ha-1 bioestimulant for Brachiaria hybrid, Convert HD364. For the second experiment, concluded that Starter N® associated with the bioestimulant and urea promotes greater accumulation of MS of forage. Starter N® associated with urea, Mastermins Pastureland® associated with urea and biostimulating and Starter N® associated with urea and the bioestimulant promote increases in accumulation of MS from leaves and stems. Starter® associated with urea, Mastermins Pastureland® associated with urea, Mastermins Pastureland® associated with urea and the bioestimulant and Starter® associated with urea and the bioestimulant promotes an increase in the accumulation of MS of dead material. Mastermins Pastureland® associated with urea and the bioestimulant and Starter® associated with urea and the bioestimulant promotes an increase in the rate of accumulation of leaf. Starter® associated with urea, Mastermins Pastureland® associated with urea and the bioestimulant and Starter® associated with urea and the bioestimulant promotes increased rate of accumulation of stalk rot.
Dissertação (Mestrado)
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22

Lacasse, Pierre. "Influence of plane of nutrition, growth hormone and growth factors on mammary gland development and function." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41650.

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Dairy heifers were submitted to high or moderate plane of nutrition before and during first gestation. High plane of nutrition did not increase milk production but negatively affected reproduction and health. In addition, high plane of nutrition decreased growth hormone (GH) concentration and increased prolactin concentration during gestation. There was no effect of previous plane of nutrition on peripartum concentrations of hormones. Milk production was positively correlated with GH concentrations, but was negatively correlated to concentrations of insulin-like growth factor-1(IGF-1) concentrations postpartum.
The effect of GH administration on mammary vasculature and on paracrine secretion of growth factors was investigated in lactating and non-lactating dairy cows. The injection of GH induced a linear increase of IGF-1 concentration in blood and mammary primary lymph, but did not affect concentrations of prostaglandin E$ sb2$ (PGE$ sb2$) concentrations. However, the rate of IGF-1 increase was slower in lymph than in blood, suggesting that blood is the source of most lymph IGF-I. Therefore, GH did not seem to affect paracrine secretion of IGF-1 and PGE$ sb2$ by the bovine mammary gland. Growth hormone administration induced a gradual increase in mammary blood flow in lactating cows while it remained constant in non-lactating animals. Changes in lymphatic, but not blood, concentrations of a stable metabolite of the vasodilatator prostacyclin I$ sb2$ parallelled the changes in blood flow. This indicates that local secretion of this vasodilatator may be responsible for the effect of GH on mammary blood flow.
Mitogenic activity of mammary primary lymph samples taken at different physiological stages was evaluated on mammary epithelial and mammary fibroblast cell lines. The results indicate that the mitogenic activity of lymph in epithelial cells was not related to physiological stage but to PGE$ sb2$ concentration. In fibroblasts, mitogenic activity of lymph was not related to physiological stage or to the content in any of the growth factors assayed.
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23

Fong, Denise Lynn. "Enhancing herbicide efficacy on reed canary grass (Phalaris arundinacea) by testing a plant growth hormone, application times, and herbicide type." Wright State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=wright1368657077.

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24

Pitelli, Angelica Maria de Campos Machado. "Controle hormonal do crescimento de raízes de tomateiro (Lycopersicon esculentum cv. Micro-Tom) em condições de déficit hídrico." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-05042006-163611/.

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A deficencia hídrica é o principal fator de estresse para o crescimento vegetal. Dentre os mecanismos de resistência à seca tem-se a resposta de crescimento radicular sob condições de déficit hídrico. Esta resposta assume-se ser regulada por hormônios vegetais. Uma abordagem interessante para o estudo de processos regulados por hormônios é a utilização de mutantes hormonais em um modelo genético. O tomateiro cv. Micro-Tom por seu porte reduzido e ciclo de vida curto constitui em bom modelo genético. Mutantes hormonais em tomateiro com baixo nível endógeno de ABA (sit, flacca), insensível a etileno (Nr), com superprodução de etileno (epi) e insensível à auxina (dgt) constituem-se valiosas ferramentas para o estudo da ação hormonal na regulação de processos fisiológicos. O presente trabalho teve como objetivo estudar a interação hormonal na regulação do processo de crescimento radicular em condições de déficit hídrico no cultivar Micro-Tom de tomateiro. Sementes germinadas de MT e dos mutantes sit, dgt, epi, e Nr foram colocadas em caixas Gerbox pretas contendo água e soluções de PEG apresentando potenciais de – 0,3; -0,6; -0,9; -1,2 MPa. Após cinco dias foi avaliado o comprimento da raiz e do hipocótilo. Também foram realizados experimentos com sementes de MT e dos mutantes em Gerbox contendo inibidores da biossíntese de ABA (fluridone), da ação do etileno, o tiossulfato de prata (STS) e um liberador desse mesmo hormônio, o ácido 2-cloro-etil-fosofonico (CEPA) em água e em solução de PEG com potencial osmótico de – 0,6 MPa. O comprimento das raízes foi avaliado após cinco dias. O potencial osmótico de – 0,6 MPa favoreceu o crescimento radicular nos genótipos MT, dgt e epi e em menor grau em Nr. Esse crescimento não ocorreu nos genótipos sit. No mutante sit há um inchaço semelhante ao provocado por excesso de etileno. Quando foi adicionado o CEPA (etileno), houve inibição severa do crescimento radicular em água em MT e em sit. A inibição foi menor em dgt. Em potencial de -0,6 MPa a inibição foi mais severa do que em água no MT. A inibição do etileno provocada pelo STS, causou uma maior diferença entre o crescimento em água e no potencial de -0,6 MPa no MT à medida em que se aumentava a concentração de STS. Em dgt tais diferenças não foram observadas. Quando se adicionou fluridone, à medida que se aumentou a dose, houve uma maior inibição do crescimento radicular, sendo que esta inibição foi menos acentuada em Nr e dgt. Em potencial de – 0,6 MPa a inibição foi mais acentuada mas seguiu a mesma tendência observada em água. Em altas concentrações de fluridone houve ramificação das raízes, interferindo no comprimento radicular. Pode-se concluir que em condições de déficit hídrico moderado há um aumento do crescimento radicular quando comparado a condições normais de suprimento hídrico. Esse crescimento provavelmente é controlado por um balanço ABA/IAA, o qual modula a resposta ao etileno.
Drought is the major abiotic plant stress factor. Among the mechanisms of water deficit resistance the root growth response has expressive importance. This response seems to be regulated by hormones. An interesting method to study hormone regulated processes is the use of hormonal mutants. The tomato cultivar Micro-Tom (MT) have reduced size and short life cycle and therefore constitutes an excellent genetic model for physiology studies. Hormonal mutants in MT with low endogenous ABA (sit and flc), ethylene insensitivity (Nr), ethylene overproduction (epi) and auxin insensitivity (dgt) constitute valuable tools to study hormone action in plant development.The present work aimed to study the hormonal interaction in the control of root growth of tomato MT subjected to water deficit. Germinated seeds of MT and mutants epi, sit, Nr, e dgt were placed in a black Ger-Box containing water and PEG 6000 solutions with potentials of - 0,3; -0,6; -0,9 e 1,2 MPa. After 5 days the length of root and hypocotyls were measured. Others experiments were conducted in Ger-Box containing ethylene action inhibitor, silver thiosulphate (STS), ABA biosynthesis inhibitor (Fluridone) and an ethylene releaser, 2-chloroethyl-phosphonic acid (CEPA) in different concentrations in water and in a -0,6 MPa osmotic potential PEG solution. After 5 days the length of the roots were measured. The PEG solution of – 0,6 MPa promoted root growth in MT, dgt, epi and in with less intensity in Nr . The promotion of root growth did not occur in sit. In the mutant sit, low potential caused a swelling in the roots similar to excess ethylene symptoms. When CEPA was used, a severe inhibition of root growth occurred. The inhibition was less intense in dgt. In the – 0,6 MPa solution the inhibition was more severe than occurred in water in MT. When ethylene action was inhibited by the application of STS, a greater difference of root growth between water and – 0,6 MPa PEG solution occurred as the STS concentration increased. In the mutant dgt these differences were not observed. In the experiment with fluridone as the dose increased the inhibition in the root growth increased concomitantly. The inhibition was less severe in Nr and dgt. In higher doses of fluridone root ramification occurred, interfering in the primary root length. By these results it can be concluded that a moderate water deficit promotes root growth better than in a normal water supply condition. Probably this growth is regulated by an ABA/IAA balance which modulates ethylene response.
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25

Sa, Ariadne Felicio Lopo de. "Mutations affecting tomato (Solanum lycopersicum L. cv. Micro-Tom) response to salt stress and their physiological meaning." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11144/tde-26092016-125619/.

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Salinity is a challenge for crop productivity. Hence, plants exposed to saline environments reduce their vegetative and reproductive growth due to adverse effects of specific ions on metabolism and water relations. In order to cope with salinity, plants display physiological mechanisms based on three main aspects: i) source-sink relationships, ii) resource allocation and iii) alterations in endogenous hormone levels. The roles of developmental and hormonal mechanisms in salt response were investigated here. We employed mutants and transgenic tomato plants affecting different aspects of plant development and hormone response in the same genetic background (cultivar Micro-Tom). The following genotypes were used: Galapagos dwarf (Gdw), Lanata (Ln), lutescent (l), single flower truss (sft), sft heterozygous (sft/+), diageotropica (dgt), entire (e), Never ripe (Nr), epinastic (epi), procera (pro), notabilis (not), anti sense Chloroplastic carotenoid cleavage dioxygenase 7 (35S::asCCD7) and Salicylate hydroxylase (35S::nahG). Among the developmental genotypes studied, sft and l, involved in flower induction and senescence, respectively, were less affected when exposed to salt stress. Although l is considered deleterious due to its precocious senescence, it presented greater shoot biomass and leaf area during salinity. The heterozygous sft/+, whose high productivity was recently linked to an improved vegetative-to-reproductive balance, changed this balance and lowered its yield more than the control MT upon salt treatment. In the analysis of genotypes affecting hormonal status/signaling four kinds of salt responses among the genotypes were observed: i) High shoot growth in spite of high Na:K ratio presented by the strigolactone deficient and high branching CCD7 transgene; ii) High shoot growth and reduced accumulation of Na in tissues (probably due to dilution) presented by the auxin constitutive response e mutant; iii) The opposite response observed in \"ii\" presented by the low auxin sensitivity dgt mutant and iv) growth inhibition combined with reduced levels of Na and higher accumulation of K presented by the not mutant, which produces less ABA. Taken together, the results presented here points to novel developmental mechanisms, such as the promotion of moderate senescence and vegetative growth, and hormonal imbalances to be explored in the pursuing of crops resistant to salt stress.
A salinidade é um desafio para a produtividade agrícola, uma vez que plantas expostas à salinidade tem o crescimento vegetativo e reprodutivo reduzido devido aos efeitos adversos de íons específicos no metabolismo e nas relações hídricas. A fim de lidar com a salinidade, as plantas desempenham mecanismos fisiológicos baseados em três principais características: i) relações fonte-dreno; ii) alocação de reservas e iii) alterações nos níveis endógenos de hormônios. Nesse trabalho, investigamos a relação entre os processos de desenvolvimento e de regulação hormonal com a resposta à salinidade. Para tanto foram usados genótipos de tomateiro com alteração em diferentes vias de desenvolvimento e de produção ou sinalização de hormônios vegetais. Os seguintes genótipos foram usados: Galapagos dwarf (Gdw), Lanata (Ln), lutescent (l), single flower truss (sft), sft heterozygous (sft/+), diageotropica (dgt), entire (e), Never ripe (Nr), epinastic (epi), procera (pro), notabilis (not), anti sense Dioxigenase cloroplastídica de carotenoide 7 (35S::asCCD7) e Salicilato hidroxilase (35S::nahG). Entre os genótipos de desenvolvimento estudados, sft e l, relacionados à menor indução floral e senescência respectivamente, foram os menos afetados quando expostos à salinidade. O genótipo l acumulou maior biomassa e área foliar, apesar de ser considerado deletério devido à senescência precoce. As plantas heterozigotas, sft/+, cuja maior produtividade foi recentemente relacionada a um melhor balanço vegetativo/reprodutivo, alteraram esse balanço sob salinidade e reduziram sua produtividade mais que o controle MT sob estresse salino. Na análise dos genótipos com alteração hormonais foram observados quatro tipos de respostas à salinidade: i) elevado crescimento da parte aérea, apesar da razão Na:K ser alta no genótipo CCD7 cujo transgene induz deficiência de estrigolactona e excessiva ramificação; ii) elevado crescimento e acúmulo reduzido de Na nos tecidos (devido provavelmente a diluição) apresentada pelo mutante de resposta constitutiva a auxina e; iii) o oposto da resposta anterior foi apresentado pelo mutante pouco sensível à auxina , dgt; iv) inibição do crescimento combinado com nível reduzido de Na e alto acúmulo de K apresentada pelo mutante not que produz menos ácido abscísico. Considerados em conjunto, os resultados apresentaram temas para novos mecanismos de desenvolvimento, como a promoção moderada de senescência e do crescimento vegetativo além dos desbalanços hormonais, para serem explorados na busca de culturas resistentes ao estresse salino.
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26

Collins, Melissa. "Effects of plant sterols and exercise training on apolipoprotein A and B, adiponectin, growth hormone and ghrelin in hypercholesterolemic sedentary adults." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99331.

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Plant sterols (PS) lower total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and inflammatory markers, and decrease risk of atherosclerotic cardiovascular disease (CVD). Exercise increases high density lipoprotein cholesterol (HDL-C) levels and decreases triglycerides (TG) and inflammation, also reducing the risk of CVD. The study objective was to investigate the combined effects of PS and exercise on apolipoproteins (apo) A and B, adiponectin, growth hormone (GH) and ghrelin, in context of previously obtained lipid data. In an 8-wk, placebo-controlled, parallel-arm clinical trial, 84 subjects were randomly assigned to: (1) combination of PS and exercise, (2) exercise, (3) PS, or (4) control group. PS increased (P=0.04) adiponectin values by 15%. ApoA was associated with HDL and apoB with LDL values at baseline. ApoA %change was correlated to HDL %change in the exercise group. ApoB, GH and ghrelin were unchanged. The capability of PS to increase adiponectin values reinforce their role in preventing inflammation, atherosclerosis, and CVD.
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27

Battistus, Andre Gustavo. "Inoculação via semente e foliar de Azospirillum brasilense associado ao tratamento de sementes com bioativador na cultura do milho." Universidade Estadual do Oeste do Paraná, 2015. http://tede.unioeste.br:8080/tede/handle/tede/1259.

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The maize is a cereal with high economic importance due to its magnitude forms of use. Increasing productivity levels, promoting substances plant development are highlighted role in contemporary agriculture, arising from biological or chemical origin. However, the lack of results regarding the joint use of these promoters leads to the need for information on their simultaneous use. In this context, this work aimed to evaluate the effects of joint use of thiamethoxam combined with seed inoculation and foliar spray Azospirillum brasilense on physiological quality of corn seeds and its agronomic performance in two environments in the growing field. Initially, we tested bacterial growth in culture medium containing increasing concentrations of thiamethoxam. It was also evaluated the initial development and physiological quality of seedlings by morphometric measurements, emergency speed index and SPAD index through factorial 2 x 3 with seed inoculation with A. brasilense (100 mL per 25 kg seeds) thiamethoxam and three doses (0, 28 and 42 mg per 60,000 seeds). In the field, factorial 2 x 4 was composed by the presence and absence of chemical seed treatment with bioactivator of thiamethoxam plants (28 mg per 60,000 seeds), while the second factor comprised seeds without inoculation; seed inoculation with A. brasilense (100 mL per 60,000 seeds), foliar spray inoculant base A. brasilense (300 mL ha-1) and associated with the seed inoculated with A. brasilense foliar spray, tested in high ambient and applying average production technology. The treatments were evaluated by morphometric analysis, nutrient content in plant tissues, components production and crop yield. The bacterial population showed a linear decrease with increasing doses of thiamethoxam. The dose of 42 mg of thiamethoxam caused reduction in emergence speed, SPAD index, shoot length and root, root volume, root/shoot and dry matter of shoots, while inoculation showed activity positive physiological quality of seedlings. Thus, combined with inoculation dose of 28 mg thiamethoxam demonstrates synergistic effect in the early development of maize seedlings. In the field, thiamethoxam, as well as seed inoculation + foliar spray promote increase in plant length, stem diameter, leaf and mass accumulation area throughout the plant cycle in both environments. Reduction in moisture content, impurities and discounts of grain mass, as well as increases in leaf phosphorus levels are the result of inoculation, yet without deterioration in corn yields. Thiamethoxam also reduced the moisture of the grain mass. Productivity was increased by the presence of thiamethoxam on average productive technology environment
O milho é um cereal de elevada importância econômica devido à sua magnitude de formas de utilização. Incrementando os níveis de produtividade, substâncias promotoras de desenvolvimento vegetal ganham papel de destaque na agricultura contemporânea, advindas de origem biológica ou química. Contudo, a escassez de resultados a respeito da utilização conjunta desses promotores leva à necessidade de informações sobre sua utilização simultânea. Neste contexto, esta obra buscou avaliar os efeitos da utilização conjunta de tiametoxam aliado à inoculação via semente e pulverização foliar de Azospirillum brasilense na qualidade fisiológica de sementes de milho e seu desempenho agronômico em dois ambientes de investimento em cultivo a campo. Inicialmente, testou-se o crescimento bacteriano em meio de cultura contendo concentrações crescentes de tiametoxam. Avaliou-se também o desenvolvimento inicial e qualidade fisiológica de plântulas por medidas morfométricas, índice de velocidade de emergência e índice SPAD, por meio de arranjo fatorial 2 x 3, com inoculação de sementes com A. brasilense (100 mL por cada 25 kg de sementes) e três doses de tiametoxam (0, 28 e 42 mg por 60.000 sementes). À campo, esquema fatorial 2 x 4 foi composto pela presença e ausência de tratamento químico de sementes com o bioativador de plantas tiametoxam (28 mg por 60.000 sementes), enquanto o segundo fator englobou sementes sem inoculação; inoculação de sementes com A. brasilense (100 mL por 60.000 sementes), pulverização foliar de inoculante a base de A. brasilense (300 mL ha-1) e inoculação de sementes associado à pulverização foliar com A. brasilense, testados em ambientes de alta e média aplicação de tecnologia de produção. Os tratamentos foram avaliados por análises morfométricas, teor de nutrientes nos tecidos vegetais, componentes da produção e produtividade da cultura. A população bacteriana mostrou redução linear de acordo com o aumento das doses de tiametoxam. A dose de 42 mg de tiametoxam causou redução na velocidade de emergência, índice SPAD, comprimento de parte aérea e de raiz, volume de raiz, relação raiz/parte aérea e massa da matéria seca de parte aérea, enquanto que, a inoculação evidenciou atividade positiva na qualidade fisiológica das plântulas. Deste modo, a inoculação combinada com dose de 28 mg de tiametoxam demonstra efeito sinérgico no início do desenvolvimento de plântulas de milho. À campo, o tiametoxam, assim como a inoculação via semente + pulverização foliar, promoveram incrementos no comprimento das plantas, diâmetro de colmo, acúmulo de massa e área foliar ao longo do ciclo vegetal em ambos os ambientes. Redução no teor de umidade, impurezas e descontos da massa de grãos, assim como incrementos nos níveis foliares de fósforo são resultados da inoculação, contudo sem apresentar alterações na produtividade do milho. Tiametoxam também reduziu a umidade da massa de grãos. A produtividade foi incrementada pela presença do tiametoxam em ambiente de média tecnologia produtiva
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28

Westerlund, Stephanie. "Measuring juvenile hormone and ecdysteroid titers in insect haemolymph simultaneously by LC-MS the basis for determining the effectiveness of plant-derived alkaloids as insect growth regulators /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972100164.

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29

Dall'Orto, Luigi Tancredi Campo. "Auxinas e tipos de estacas no enraizamento de Camellia sinensis." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/11/11136/tde-21092011-104432/.

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Com o objetivo de avaliar a influência de cultivares, tipos de estacas de Camellia sinensis e doses de ácido indolbutírico no enraizamento de estacas, dois experimentos foram conduzidos em casa de vegetação, no delineamento experimental em blocos ao acaso com 16 tratamentos, no esquema fatorial 2 x 2 x 4, ou seja, tipos de estaca (herbácea e lenhosa), cultivares (Camellia sinensis IAC 259 e Yabukita) e quatro doses de ácido indolbutírico (AIB) (0, 30, 60 e 90 mg L-1), com quatro repetições. Cada repetição foi composta por 20 estacas da porção mediana dos ramos das plantas matrizes, coletadas em duas épocas do ano (verão e inverno). As estacas foram cortadas em bisel e mantidas com uma gema e uma folha inteira, com 5 a 7 cm de comprimento. A região basal das estacas recebeu ou não tratamento com ácido indolbutírico (AIB), através da imersão de 2,5 cm da base em solução aquosa do produto por 24 horas. Posteriormente, elas foram colocadas em bandejas de isopor de 72 células contendo vermiculita de grânulos médios. As estacas herbáceas apresentaram maior porcentagem de enraizamento com a aplicação de AIB comparada às estacas lenhosas, sendo que as estacas coletadas no período do verão apresentaram maior porcentagem de enraizamento em menor espaço de tempo, quando comparadas com as estacas coletadas no período do inverno. Estacas da cultivar Yabukita apresentaram maior potencial de enraizamento em relação às estacas da cultivar IAC 259. As concentrações recomendadas de AIB para o enraizamento de estacas de Camellia sinensis variaram de 56 a 83 mg L-1 em função da cultivar.
Aiming to evaluate the influence of Camellia sinensis cultivars, types of cuttings and doses of IBA on rooting, two experiments have been conducted in a green house in the experimental design in blocks randomized with 16 treatments, arranged in a 2 x 2 x 4, that is, cutting types (herbaceous and woody), cultivars (Camellia sinensis \'IAC 259\' and \'Yabukita\') and four doses of butyric acid (IBA) (0, 30, 60 and 90 mg L -1) with four replications. Each replication consisted of 20 cuttings from the middle portion of the branches from the mother plants, collected in two seasons (summer and winter). The cuttings were cut in bevel and maintained with a bud and a leaf, with 5-7 cm long. The basal cuttings have received or not treatment with indol butyric acid (IBA) by immersion of 2.5 cm from the base in an aqueous solution of the product for 24 hours. Later, they have been placed in trays with 72 cells containing medium granules of vermiculite. Herbaceous cuttings have presented higher percentages of rooting with IBA application compared to hardwood cuttings, and cuttings collected in summer have showed the highest percentage of rooting in the shortest time compared with the cuttings collected in winter. Yabukita cultivars cuttings had higher rooting potential in relation to the IAC 259 cuttings. IBA level to the rooting of Camellia sinensis varied from 56 to 83 mg L-1 according to cultivars
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30

Guyon, Jean-Baptiste. "Développement technologique et bioproduction d’actifs pour la cosmétique à l'aide de cultures cellulaires végétales indifférenciées." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0300.

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Les premières cultures cellulaires végétales in vitro ont été développées à partir de carotte, grâce à Gautheret en 1939. Il a obtenu ce résultat par la découverte au préalable du pouvoir de totipotence des cellules végétales (Haberland 1902). Afin d’obtenir les cellules indifférenciées Gautheret a utilisé des milieux de culture contenant des macroéléments (K, N et P), des microélements (Mg, B,…), des vitamines, du sucre et des phytohormones. Dans la littérature, plusieurs compositions sont souvent utilisées comme White (1934), Murashige and Skoog (1962)) ou Gamborg, Miller et Ojima (1970). Les nuances entre ces milieux se basent sur des concentrations modifiées en phosphates, nitrates ou en phytohormones (auxine/cytokinine). Chaque espèce a besoin d’un milieu particulier pour induire la callogénèse. En effet, selon l’origine (géographique) et le type d’explant (feuilles, racines, tiges,…) traité les conditions d’induction de la callogénèse varieront. De nombreuses personnes portent un intérêt aux cultures cellulaires pour leur utilisation en cosmétique ou en pharmacie. Actuellement, deux entreprises produisent ces cellules à l’échelle industrielle. Ainsi, Phyton Biotech (entreprise allemande) purifie du taxol à partir d’If (Taxus baccata) et Mitsui petrochemical produit de la skinonine à partir de grémils (Lithospernum erythrorizon)
The first plant cell culture has been developed by Gautheret in 1939 based on carrot plant cell tissus. He obtained these results through the discovery of the plant totipotency power (Haberland, 1902). He used for cal production a culture medium composed by macroelements (K, N, P…) and microelements (Mg, B …), vitamin, sugar. Later on, several mediums were used like and described in literature i.e. Murashige and Skoog (1962), White (1934) or Gamborg, Miller and Ojima (1970). The differences between such medium consisted mainly concentrations especially of phosphates, nitrates or auxin/cytokinine balance. However, each species needs specific medium for growth. Any people works of this subject and the interest for pharmaceutical and cosmetical industry grow up. Plant cell culture is a difficult technology an industrial use. Recently, two companies performed industrial production of taxol (Taxus baccata) and shikonin (Lithospernum erythrorizon) respectively PhytonBitotech and Mitsui petrochemical. My thesis work was to develop plant cell cultures fom unusual plants which can be used for the industrial production of cosmetics
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31

Beraud, Jacky Gilbert. "Contribution à l'étude du contrôle hormonal du transport des nutriments : valeurs et limites de la feuille isolée de pelargonium zonale comme matériel expérimental." Brest, 1988. http://www.theses.fr/1988BRES2006.

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32

Henning, Penelope Anne. "The effects of some selected herbicides and plant hormones on the growth of Prototheca wickerhamii." Thesis, 2015. http://hdl.handle.net/10539/16771.

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33

Madlung, Andreas. "Interactions of auxin with ethylene and gravity in regulating growth and development in tomato (Lycopersicon esculentum, Mill.)." Thesis, 2000. http://hdl.handle.net/1957/32601.

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Plant growth, development, and environmental responsiveness are dependent on hormone-induced gene expression. This dissertation reports multiple interactions between the plant hormones auxin and ethylene and investigates their contribution to the gravitropic response, elongation growth, adventitious root formation, callus and tracheary element initiation and growth, and flower development. Four mutants of tomato (Lycopersicon esculentum, Mill.) altered in either hormone production or hormone response were used to test the involvement of ethylene and auxin. These mutants included diageotropica (dgt) which is auxin-resistant, Never-ripe (Nr), which is ethylene-resistant, epinastic (epi), which overproduces ethylene and lazy-2 (lz-2), which exhibits a phytochrome-dependent reversed-gravitropic response. Additionally, a double mutant between Nr and dgt was constructed and tested. Gravitropism was studied as an exemplary process involving both auxin and ethylene. Mutant analysis demonstrated that ethylene does not play a primary role in the gravitropic response via the currently known ethylene response pathways. However, ethylene can modify the gravitropic response, e.g. the delayed gravitropic response of the dgt mutant can be restored with exceedingly low concentrations of ethylene and ethylene synthesis- and ethylene-action inhibitors can partially inhibit the graviresponse. The role of gravity in tracheary element (TE) production was tested in microgravity (during a space shuttle flight) and in hypergravity (centrifugation). A correlation was found between gravitational force and the production of TEs, with decreased numbers of TEs produced in microgravity and increased numbers produced in response to hypergravity. Increased production of TEs by dgt in both increased and reduced gravity indicates that gravity regulates vascular development via a DGT-dependent pathway involving auxin. Combination of both the Nr and dgt mutations in a double mutant leads to plants which exhibit the reduction of auxin-sensitivity typical of dgt as well as a delay in fruit ripening typical of Nr. The reduced gravitropic response of the dgt mutant was restored to wild-type levels in the double mutant confirming a complex role for ethylene in the gravitropic response. Abnormal floral organ development was observed in a subset of double mutant flowers.These data demonstrate multiple connections between auxin and ethylene during development and provide further insight into their cellular interactions.
Graduation date: 2001
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34

Du, Plessis Sandra. "Physiological and molecular characterization of habituated and non- habituated soybean callus lines (Glycine max (L.) Merr cv. Acme)." Thesis, 1998. http://hdl.handle.net/10413/10286.

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A cytokinin habituated soybean callus has been isolated, utilizing the cytokinin soybean bioassay. The habituated callus line was subsequently characterized with a non-habituated callus line in relationship to levels of endogenous growth substances, ultrastructure, nitrogen metabolism and pattern of gene expression. The cytokinin habituated soybean callus contained a higher level of endogenous cytokinin-like activity in comparison to the non-habituated callus. This higher level of cytokinin present is in part due to a lower rate of degradation. The habituated callus tissue produced very low levels of ethylene, while the non-habituated callus produced ethylene at a much higher rate (57 fold higher), than the habituated callus. In contrast to what was found in habituated sugarbeet callus, only low levels of putrescine could be detected in both callus types. The putrescine content of habituated callus tissue was lower than that of non-habituated callus tissue. The ultrastructure of habituated callus cells exhibited several differences to what was observed in the non-habituated callus. Habituated callus cells appeared to have a thinner cell wall than that of the non-habituated callus cells. The cristae of the mitochondria in habituated cells were thicker than that of the non-habituated callus cells, indicating a lower metabolic activity. On day 14 of the growth period the nuclei of habituated callus demonstrated active RNA synthesis as indicated by the presence of several vacuolated nucleoli. Although no significant differences between proline levels of habituated callus and proline levels of non-habituated callus were observed, it was demonstrated that there was a difference in proline metabolism between the habituated and non-habituated calli. Utilizing an inhibitor of OAT, gabaculine, it was shown that in habituated callus tissue proline originated from ornithine during the first 14 days of growth. During the second half of the growth period, which characteristically consists of tissue with low biosynthetic activity, proline originated from glutamate. The production of proline in habituated callus from ornithine also corresponded to a period of high NH₄⁺ content in both callus types, while the production of proline from glutamate corresponded to a period of low NH₄⁺ content in the cells of both callus types. No such correlation was observed in proline metabolism of non-habituated callus. A similar turning point was observed in the activity of OAT of both callus types. Although the specific activity of OAT in both callus types mirrored their changes in RNA concentration, the percentage inhibition of OAT by gabaculine was not significant from day 14 in both callus types. This may indicate a change in the catalyzing properties of OAT in both callus types. It was further demonstrated that the non-habituated callus tissue contained some inhibitor inactivating OAT activity. With the use of gabaculine it was further shown that, in contrast to what was found in other habituated calli, there is no metabolic link between proline metabolism and putrescine synthesis. Both the habituated callus and the non-habituated callus exhibited a high nitrogen influx during the first 14 days of the growth period. The low NH₄⁺ content present in both callus types during the second half of the growth period coincided with higher levels of amino acids present in both callus types. The levels of precursor amino acids (glutamate, aspartate and alanine) did not fluctuate during the growth period, indicating a tight control on amino acid pools. Levels of amino acids further down the path of metabolism did not fluctuate drastically and there appeared to be very little difference between the levels of different amino acids measured in the habituated and nonhabituated calli. Serine was the dominant amino acid in both callus types. Total RNA concentrations of habituated callus were low in comparison to that of the non-habituated callus, except for a striking 12 fold increase on day 14 of the growth period. RNA concentrations of non-habituated callus increased gradually during the growth period and the highest concentration was recorded 21 days after subculturing. Several polypeptides were observed in the habituated callus that were not present in the non-habituated callus, utilizing IEF. Three polypeptides exhibited a change in concentration from day 6 to day 14 of the growth period in both the habituated and nonhabituated callus. These polypeptides appeared to decrease in nonhabituated callus, while they increased in the habituated callus. A complete cDNA library was constructed for both of the habituated and nonhabituated callus lines. Six different clones, that were over expressed in the habituated callus tissue, were isolated via subtractive techniques. One clone was characterized and showed homology to the glutamate/aspartate transport protein, the membrane component, of E. coli.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1998.
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35

Mikasi, Masiza Samuel. "The evaluation of the nutritive value of Baobab seed cake and Macadamia oil cake as feed for ruminants." Thesis, 2018. http://hdl.handle.net/11602/1199.

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PhD (AGR) (Animal Science)
Department of Animal Science
Horticultural by-products such as seed and nut oil residues have the potential to replace conventional protein and energy sources in diets for ruminants. The objective of the study was to evaluate the nutritive value of Macadamia oil cake and Baobab seed cake as nutrient supplements for feedlot animals. Several experiments were carried-out to evaluate the nutritive value of Macadamia oil cake and Baobab seed cake as feed for ruminants. The nutrient composition of the cakes were determined using both proximate and modern methods of analysis of feeds and a t-test was used to compare the means of Macadamia oil cake and Baobab seed cake. The in sacco technique was used to determine the rumen degradability parameters of dry matter, crude protein and Amino acids of the cakes. This experiment was conducted using a completely randomized design. A three step-in vitro technique was used to conduct a post ruminal digestibility trial and the study was arranged in a completely randomized design. An apparent digestibility trial was conducted using metabolism cages and fecal bags to avoid the mixing of urine and faeces and the experiment was carried out as a completely randomized design arranged in a 2 x 2 factorial. A growth trial was conducted using a completely randomized block design arranged in a 2x2 factorial with two protein supplements and two inclusion levels as factors and blocked by sex of the lambs. The two cakes had similar (P>0.05) dry matter, fat, hemicellulose and gross energy contents. Baobab seed cake had significantly (P<0.05) higher ash, crude protein, acid detergent lignin and nitrogen free extract than macadamia oil cake. Macadamia oil cake had significantly (P<0.05) higher crude fiber, acid detergent fiber, neutral detergent fiber and cellulose concentrations. Baobab seed cake had significantly (P<0.05) higher calcium, magnesium, potassium, phosphorus (macroelements), zinc, and copper than macadamia oil cake. Macadamia oil cake was significantly (P<0.05) higher in manganese and iron contents than Baobab seed cake. Sodium content was not significantly (P>0.05) different between the two cakes. Baobab seed cake had more (Tryptophan, Cysteine, Arginine, Aspartic acid, Glutamic acid, Valine, Phenylalanine, Isoleucine, Leucine) Amino acids which were significantly (P<0.05) higher in quantity than macadamia oil cake with the two cakes having similar (P>0.05) remaining Amino acids contents. Generally Macadamia oil cake had more (P<0.05) saturated and mono-unsaturated fatty acids than Baobab seed cake whereas Baobab seed cake had more (P<0.05) poly-unsaturated fatty acids. v The in sacco rumen degradability characteristics of baobab seed cake and macadamia oil cake were estimated for dry matter and crude protein of the cakes. Macadamia oil cake had significantly (P<0.01) higher a value for dry matter than boabab seed cake. Baoaba seed cake had significantly (P<0.01) higher a value for crude protein than macadamia oil cake. the b, c, and a+b values for dry matter of both Baobab seed cake and Macadamia oil cake were not significantly (P>0.05) different form each other. However, the potential degradability (a+b) value for crude protein of baobab seed cake was significantly (P<0.01) higher than that of macadamia oil cake. The b and c constants of the two cakes for crude protein were not significantly (P>0.05) different from each other. The ED (Effective degradability) values calculated at three outflow rates (0.02, 0.05, 0.08) were estimated for dry matter and crude protein of Baobab seed cake and macadamia oil cake. The ED of the two cakes calculated at 0.02 outflow rate did not significantly (P>0.05) differ from each other. However, baobab seed cake had significantly (P<0.05) higher ED value at outflow rate of 0.05 whereas macadamia oil cake had significantly (P<0.05) higher ED value calculated at outflow rate of 0.08. The ED values of baobab seed cake for crude protein calculated at the three outflow rate were significantly (P<0.01) higher than those of macadamia oil cake. The two cakes did not significantly (P>0.05) differ in dry matter ruminal degradability but baobab seed cake had significantly (P<0.05) higher ruminal crude protein disappearance from 16 to 72 hours of incubation than macadamia oil cake. The in situ Amino acid degradation was determined on 0, 12, 16, 24, and 48 hour of ruminal incubation of the cakes’ samples and generally they were significant (P<0.05) differences for both cakes according to different incubation periods. The 3-step in vitro digestibility trial revealed that baobab seed cake had significantly (P<0.05) higher dry matter, crude protein and Amino acids digestibility values than macadamia oil cake. Apparent digestibility study revealed that nutrient intake, faecal and urine outputs, and digestibility of nutrients were not significantly (P>0.05) different between baobab seed cake and macadamia oil cake. However, lambs on 10% macadamia cake having retained significantly (P<0.05) more nitrogen than the lambs on 15% macadamia oil cake, 10% and 15% baobab seed cakes diets. However, the inclusion of either baobab seed cake or macadamia oil cake at 10% or 15% in the diets of lambs did not significantly (P>0.05) affect the DOMR, microbial protein yield and purine derivates output. For the growth trial the lambs were offered four diets formulated to contain 10% MOC (control), 15% MOC, 10 BSC and 15% BSC. The inclusion of 15% MOC and 10% BSC in the diets of lambs did not significantly (P>0.05) affect their final body weight, total weight gain, average daily feed intake, average daily weight gain, warm and cold carcass masses between these two vi groups. The inclusion of 10% MOC and 15% BSC in the diets of lambs did not significantly affect average daily feed intake and animal performance between these two groups. However, lambs on 10% MOC and 15% BSC had significantly (P<0.05) higher average daily feed intake and animal performance compared to lambs on 15% MOC diet. The feed conversion efficiency and of the lambs in the four diets were not significantly (P>0.05) different. The dressing percentage, carcass length, neck weight, fat thickness, body weight thickness and rib eye area of the carcasses of lambs in this trial did not differ significantly (P>0.05) except for spleen and skin with lambs on 10% BSC diets having the least skin weight and lambs on 10% MOC diet having heaver spleens. Generally BSC had higher (P<0.05) nutrient content than MOC. BSC and MOC were highly degradable in the rumen whereas BSC was higly digestible post-ruminally compared to MOC. The diets of fattening lambs formulated to include 10% or 15% of BSC or MOC as protein supplements did not affect the apparent digestibility of the diets. Macadamia oil cake can be incomporated in the diet of finishing lambs as a protein supplement at 10% inclusion level without compromising the growth and carcass characteristics of the lambs. Baobab seed cake as a protein supplement can be included in the diet of finishing lambs at up to 15% inclusion level without deleteriously compromising on the growth and carcass characteristics of the animals. ______________________________________
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36

Bao, Yanghuan. "Genome scale transcriptome analysis and development of reporter systems for studying shoot organogenesis in poplar." Thesis, 2008. http://hdl.handle.net/1957/8329.

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Vegetative propagation allows the amplification of selected genotypes for research, breeding, and commercial planting. However, efficient in vitro regeneration and genetic transformation remains a major obstacle to research and commercial application in many plant species. Our aims are to improve knowledge of gene regulatory circuits important to meristem organization, and to identify genes that might be useful for improving the efficiency of in vitro regeneration. In this thesis, we have approached these goals in two ways. First, we analyzed gene expression during poplar (Populus) regeneration using an AffymetrixGeneChip® array representing over 56,000 poplar transcripts. We have produced a catalog of regulated genes that can be used to inform studies of gene function and biotechnology. Second, we developed a GUS reporter system for monitoring meristem initiation using promoters of poplar homologs to the meristem-active regulatory genes WUSCHEL (WUS) and SHOOTMERISTEMLESS (STM). This provides plant materials whose developmental state can be assayed with improved speed and sensitivity. For the microarray study, we hybridized cDNAs derived from tissues of a female hybrid poplar clone (INRA 717-1 B4, Populus tremula x P. alba) at five sequential time points during organogenesis. Samples were taken from stems prior to callus induction, at 3 days and 5 days after callus induction, and at 3 and 8 days after the start of shoot induction. Approximately 15% of the monitored genes were significantly up-or down-regulated based on both Extraction and Analysis of Differentially Expressed Gene Expression (EDGE) and Linear Models for Microarray Data (LIMMA, FDR<0.01). Of these, over 3,000 genes had a 5-fold or greater change in expression. We found a very strong and rapid change in gene expression at the first time point after callus induction, prior to detectable morphological changes. Subsequent changes in gene expression at later regeneration stages were more than an order of magnitude smaller. A total of 588 transcription factors that were distributed in 45 gene families were differentially regulated. Genes that showed strong differential expression encoded proteins active in auxin and cytokinin signaling, cell division, and plastid development. When compared with data on in vitro callogenesis from root explants in Arabidopsis, 25% (1,260) of up-regulated and 22% (748) of down- regulated genes were in common with the genes that we found regulated in poplar during callus induction. When ~3kb of the 5' flanking regions of close homologs were used to drive expression of the GUSPlus gene, 50 to 60% of the transgenic events showed expression in apical and axillary meristems. However, expression was also common in other organs, including in leaf veins (40% and 46% of WUS and STM transgenic events, respectively) and hydathodes (56% of WUS transgenic events). Histochemical GUS staining of explants during callogenesis and shoot regeneration using in vitro stems as explants showed that expression was detectable prior to visible shoot development, starting 3 to 15 days after explants were placed onto callus inducing medium. Based on microarray gene expression data, a paralog of poplar WUS was detectably up-regulated during shoot initiation, but the other paralog was not. Surprisingly, both paralogs of poplar STM were down-regulated 3- to 6-fold during early callus initiation, a possible consequence of its stronger expression in the secondary meristem (cambium) than in shoot tissues. We identified 15 to 35 copies of cytokinin response regulator binding motifs (ARR1AT) and one copy of the auxin response element (AuxRE) in both promoters. Several of the WUS and STM transgenic events produced should be useful for monitoring the timing and location of meristem development during natural and in vitro shoot regeneration.
Graduation date: 2008
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37

Westerlund, Stephanie [Verfasser]. "Measuring juvenile hormone and ecdysteroid titers in insect haemolymph simultaneously by LC-MS : the basis for determining the effectiveness of plant-derived alkaloids as insect growth regulators / vorgelegt von Stephanie Westerlund." 2004. http://d-nb.info/972100164/34.

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38

Ojelade, Babatube Solomon. "Regeneration potential of selected medicinal plants used to treat human and livestock diseases in Limpopo Province of South Africa." Diss., 2017. http://hdl.handle.net/11602/1069.

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MSCAGR ( Plant Production)
Many high valued tree species of medicinal significance in the Limpopo Province, South Africa exhibit seed dormancy, and also contain aromatic oils which inhibit rooting of their stem cuttings. These plant species are under pressure due to human over-exploitation. The main objective of this study was to investigate effects of rooting hormones on the rooting ability that will help in domesticating some of the selected high valued medicinal plants, Elaeodendron transvaalense (bushveld saffron), Brackenridgea zanguebarica (yellow peeling plane), and Warburgia salutaris (pepper-bark tree). Stem cuttings of these plant species were prepared and treated with various concentrations (500, 1000 and 2000 ppm) of IBA, IAA and NAA in different growth media (Natural soil, farm soil and hygromix) at a nursery house. 180 experimental units were sown and arranged in Randomized Complete Block Design (RCBD), each treatment replicated five times and then monitored for a period of three months. Data were only obtained from Brackenridgea zanguebarica as other species dried up two weeks after sprouting. The two variables measured from the experiments were sprouted stems and number of leaves. The data obtained were subjected to analysis of variance and least significant difference (LSD) at 5% probability level was used to compare treatment using STATISTICA software analysis package. The hormone, hormone concentration, growth media and their interactions had effect on sprouted stems and number of leaves produced on Brackenridgea zanguebarica cuttings, with no record of rooting ability. IBA (500 ppm and 1000 ppm) and control (without rooting hormone) showed high significant results with natural soil and farm soil in terms of leaf production compared to the hygromix, which is significantly lower from others. IBA at the various concentrations (500, 1000 and 2000 ppm) and the control gave the highest percentage sprouted stem on both natural soil and farm soil as compared with other hormones at the same
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