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Abd, Razak Shamsul Bahri B. "Development and distribution of laticifers in plants." Thesis, Durham University, 2000. http://etheses.dur.ac.uk/4485/.
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Distribution, cytological organization and development of laticifers In some latex bearing plants were studied by the use of optical and electron microscopy. Seven species from five different families were used In a comparative study, which were Meconopsis cambrica & Papaver rhoeas (Papaveraceae), Hevea brasiliensis & Euphorbia wulfenii (Euphorbiaceae), Musa acuminata (Musaceae), Mandevilla splendens (Apocyanaceae) & Taraxacum officinale (Compositae/Asteraceae). Several preparation procedures have been compared and optimised for the structural preservation of the laticifers and for examination of their distribution in these taxa. Methods of fixation have been studied. Fresh unfixed samples showed good structural information and laticifer distribution in the tissue. This technique was also very fast and convenient to use. In practice this protocol can be applied in monitoring and screening bulk samples in a breeding program, where speed and convenience are very important. Samples fixed with aldehyde fixative gave reasonably good results for histology study but not at the electron microscope level. The samples fixed with this fixative however, were highly suited to Immunohistochemical work. This information is invaluable and will be used and adapted for Hevea study in Malaysia. Both osmium and a combination of osmium tetroxide and zinc iodide were superior in term of ultrastructural preservation. Embedding media for laticifers were compared. For histological and immunohistochemical studies, Paraplast wax was used. The preparation procedure was easy and convenient, and overall structural information of laticifers was good. Spurr resin and araldite are both epoxy resins, but samples embedded in araldite gave better, more acceptable results. The carcinogenic nature of Spun- resin means that it must be handled with extreme caution, making it a less convenient embedding medium. The only acrylic resin was LR White, which was initially Intended for an immunocytochemistry study where the priority was to retain antigenic sites. Samples embedded with this resin did not show good structural information. The final set of procedures evaluated was staining methods. The staining procedure has to be fast, must differentially stain laticifers and must be reliable. These stains can be grouped into two categories; standard histological stains such as Toluidine Blue and Safranin O with Astra Blue, and fluorescent stains such as Calcofluor, ANS and Acridine Orange. However almost all stains tested failed to differentially stain latex or laticifers. They however did assist in clarifying for identification the location and distribution of laticifers in the tissues. Using Toluidine Blue was very fast and easy, but all the fluorescent stains are faster and easier to use. Laticifers in all species examined, exhibited a similar pattern of distribution. They were located in the cambial regions of stems, petioles, leaves and roots, or closely located within the vascular bundle.
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Silva, Rayanne Farias da. "Histological analysis of tissues cultured in vitro laticÃferas plants, soluble protein profile and action against plant pathogens." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14733.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorLaticifers plants have been studied by presenting a wide range of proteins related to plant defense in its latex. The aim of this study was to investigate, in tissue cultured in vitro, proteins and activities described for latex laticÃferas two species. Tissue callus and roots of Cryptostegia grandiflora were obtained by in vitro tissues culture protocols and subjected to histological analysis for laticifers characterization. Cultured tissue of Calotropis procera were used as comparative reference in the analysis. There wasnât any laticifer structure in callus or roots of C. grandiflora while in C. procera laticifers are formed in the roots. Soluble proteins were extracted from the cultured tissue and characterized using enzymatic assays, biochemical, immunological techniques and mass spectrometry. The presence of activity against phytopathogenic fungi was investigated and all data obtained were compared with the previously one determined for the plants studied latex. Callus and roots proteins of C. procera showed antifungal activity against pathogenic fungi. The percentage inhibition of the vegetative hyphae growth in the presence of callus and roots C. procera protein respectively were 75.5% and 82.6% for Fusarium solani, 76.7% and 57.1% for Rhizoctonia solani, 88.8% and 79.8% for Fusarium oxysporum, 93.7% and 90.2% for Colletotrichum lindemuthianum and 80.2% and 79.7% for Colletotrichum gloesporioides, however, showed no effect on Mucor sp. Callus and roots proteins of C. grandiflora showed no inhibitory effect on the hyphae growth or spores germination of assayed fungi. Through assays using fluorescent markers, it was demonstrated that proteins extracted from in vitro culture of C. procera interact with the membrane of C. gloesporioides causing leakage of cytoplasmic contents, possibly suggesting that its mechanism of action against fungi is related to the change in plasma membrane permeability. Also oxidative stress was observed in C. gloesporioides spores treated with callus and roots protein C. procera by hydrogen peroxide production. Protease inhibitors, chitinases, osmotins and proteases were detected in the C. procera callus and roots samples, however, osmotins and proteases were not observed in C. grandiflora callus and roots. The activity of antioxidant enzymes APX, G-POD and catalase were observed in tissue cultured in vitro of C. grandiflora. Considering that C. grandiflora laticifers proteases were demonstrated exert action against fungi, the results observed in this study suggest that the absence of antifungal activity in C. grandiflora cultured tissue is due to the absence of proteases in these tissues as well exclude chitinases and proteases inhibitors as antifungal proteins. The study concludes that the use of cultured tissues that do not differentiate laticifers is an interesting model to study activities associated to proteins founded in latex. Antifungal proteases present in C. grandiflora latex were not found in the tissues without laticifer formation.
Plantas laticÃferas tÃm sido estudadas por apresentarem uma grande diversidade de proteÃnas relacionadas à defesa vegetal em seu lÃtex. O objetivo deste trabalho foi pesquisar em tecidos cultivados in vitro, proteÃnas e atividades descritas para o lÃtex de duas espÃcies laticÃferas. Tecidos de calos e raÃzes de Cryptostegia grandiflora foram obtidos atravÃs de protocolos de cultura in vitro de tecidos e submetidos à anÃlise histolÃgica para caracterizaÃÃo de laticÃferos. Tecidos cultivados de Calotropis procera foram utilizados como referencial comparativo nas anÃlises. NÃo foi detectada qualquer estrutura laticÃfera em calos ou raÃzes de C. grandiflora enquanto que em C. procera laticÃferos se formam nas raÃzes. ProteÃnas solÃveis foram extraÃdas dos tecidos cultivados e caracterizadas por meio de ensaios enzimÃticos, tÃcnicas bioquÃmicas, imunolÃgicas e espectrometria de massas. A presenÃa de atividade contra fungos fitopatogÃnicos foi investigada e todos os dados obtidos foram comparados com dados previamente determinados para os lÃtex das espÃcies estudadas. ProteÃnas dos calos e raÃzes de C. procera, apresentaram atividade antifÃngica sobre fungos fitopatogÃnicos. Os percentuais de inibiÃÃo do crescimento vegetativo de hifas na presenÃa de proteÃnas de calos e raÃzes de C. procera, respectivamente, foram: 75,5% e 82,6% para Fusarium solani, 76,7% e 57,1% para Rhizoctonia solani, 88,8% e 79,8% para Fusarium oxysporum, 93,7% e 90,2% para Colletotrichum lindemuthianum e 80,2% e 79,7% para Colletotrichum gloesporioides, no entanto, nÃo demonstraram nenhum efeito sobre Mucor sp. As proteÃnas de calos e raÃzes de C. grandiflora nÃo apresentaram qualquer efeito inibitÃrio sobre o crescimento de hifas ou germinaÃÃo de esporos dos fungos avaliados. Por meio de ensaios com marcadores de fluorescÃncia, foi possÃvel demonstrar que as proteÃnas extraÃdas da cultura in vitro de C. procera interagem com a membrana de C. gloesporioides causando extravasamento do conteÃdo citoplasmÃtico, sugerindo que possivelmente seu mecanismo de aÃÃo contra fungos esteja relacionado à alteraÃÃo na permeabilidade da membrana plasmÃtica. TambÃm foi observado estresse oxidativo em esporos de C. gloesporioides tratados com proteÃnas de calos e raÃzes de C. procera atravÃs da produÃÃo de perÃxido de hidrogÃnio. Inibidores de proteases, quitinases, osmotinas e proteases foram detectados nas amostras de calos e raÃzes de C. procera, porÃm, osmotinas e proteases nÃo foram observadas em calos e raÃzes de C. grandiflora. A atividade das enzimas antioxidantes APX, G-POD e catalase foram observadas nos tecidos cultivados in vitro de C. grandiflora. Considerando que proteases laticÃferas de C. grandiflora foram demonstradas exercer aÃÃo contra fungos, os resultados observados nesta pesquisa sugerem que a ausÃncia de atividade antifÃngica em tecidos cultivados de C. grandiflora deve-se a ausÃncia de proteases nestes tecidos e ainda excluem quitinases e inibidores de proteases presentes como proteÃnas antifÃngicas. Em calos e raÃzes de C. procera, alÃm de proteases, outras proteÃnas tais como, quitinases, inibidores de proteases e osmotinas detectadas podem estar envolvidas na atividade antifÃngica observada, e/ou agir sinergicamente na defesa contra fungos. O estudo conclui que o uso de tecidos cultivados que nÃo diferenciam laticÃferos à um interessante modelo para estudar atividades associadas Ãs proteÃnas encontradas no lÃtex. Proteases antifÃngicas presentes no lÃtex de C. grandiflora nÃo foram encontradas nos tecidos sem formaÃÃo laticÃfera.
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Ducos, Jean-Paul. "Croissance et metabolisme primaire de suspensions heterotrophes de catharanthus roseus en fermenteur : importance de la phase gazeuse." Toulouse, INSA, 1986. http://www.theses.fr/1986ISAT0031.
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Agostini, Deuber Lincon da Silva [UNESP]. "Estudo dos componentes não isoprênicos do látex de Hevea brasiliensis indutores de angiogênese." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/103766.
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agostini_dls_dr_bauru.pdf: 1803645 bytes, checksum: 1ba74c4c9393d0cd53d03478b6fe2f01 (MD5)Atualmente é comprovado o poder de indução de angiogênese e neoformação tecidual através de membranas de borracha natural de Hevea brasiliensis. Este trabalho apresenta um estudo sobre as propriedades e a caracterização das frações não isoprênicas, separadas por centrifugação do látex, utilizado como biomaterial na indução de angiogênese e de neoformação. As frações constituintes, F2 e F3 sem o tradicional agente estabilizante de hidroxido de amônio (NH4OH), foram liofilizadas para a redução da quantidade de água e estabilização, em seguida tratadas termicamente a temperatura de 40,60,80, 100, 120 e 140ºC e novamente liofilizadas, sendo caracterizada através das técnicas de Kjeldahl, Soxhlet, de espectroscopia de absorção no infravermelho (FT-IR), Ressonância Magnética Nuclear (RMn-13C). Difração de raios x (DRX), termogravimetria (TG) acoplado ao FT-IR (IG/FT-IR), calorimetria exploratória diferencial (DSC), eletroforese, dosagens de citocinas e síntese de óxido nítrico considerando o fator limitate do uso do látex como um material bioativo, que é a temperatura de tratamento térmico, realizado para a obtenção das membranas de borracha natural, em torno de 85ºC. Foi possível verificar que a fração F3 constituinte do látex, tem propriedades anti-inflamatórias e que a fração F2 possui propriedades pró-inflamatórias
Currently it is proven the hability of inducing angiogenesis and tissue neoformating through membranes of natural rubber Hevea brasiliensis, so this work presents a study on the properties and characterization of non-isoprene fractions, separated by centrifugation, the latex used as biomaterial for induction and neoformation of angiongenesis and lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized to reduce the amount of water and stabilization, and then heat treated at temperature of 40, 60, 80, 100, 120 and 140ºC bieng characterized by the techniques of kjeldahl, Soxhlet, of absorption spectroscopy infrared (FT-IR), Nuclear Magnetic Resonance (NMR-13C), X-ray Diffraction (XRD), thermogravimetry (TG) coupled to FT-IR (TG-IR), differential scanning calorimetry (DSC), electrosphoresis, serum cytokines and oxide nitric (NO) considering the limiting factor in the use of latex as a bioactive material, which is the thermal treatment temperature, held for obtaining membranes of natural rubber, about 85ºC. It was possible to verify that the fraction F3 constituent latex has anti-inflammatory and the fraction F2 take inflammatory properties
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Agostini, Deuber Lincon da Silva. "Estudo dos componentes não isoprênicos do látex de Hevea brasiliensis indutores de angiogênese /." Bauru, 2013. http://hdl.handle.net/11449/103766.
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Orientador: Aldo Eloizo JobBanca: Mariselma Ferreira
Banca: Ivan Helmuth Bechtold
Banca: José Antonio Malmonge
Banca: Eduardo René Perez
Resumo: Atualmente é comprovado o poder de indução de angiogênese e neoformação tecidual através de membranas de borracha natural de Hevea brasiliensis. Este trabalho apresenta um estudo sobre as propriedades e a caracterização das frações não isoprênicas, separadas por centrifugação do látex, utilizado como biomaterial na indução de angiogênese e de neoformação. As frações constituintes, F2 e F3 sem o tradicional agente estabilizante de hidroxido de amônio (NH4OH), foram liofilizadas para a redução da quantidade de água e estabilização, em seguida tratadas termicamente a temperatura de 40,60,80, 100, 120 e 140ºC e novamente liofilizadas, sendo caracterizada através das técnicas de Kjeldahl, Soxhlet, de espectroscopia de absorção no infravermelho (FT-IR), Ressonância Magnética Nuclear (RMn-13C). Difração de raios x (DRX), termogravimetria (TG) acoplado ao FT-IR (IG/FT-IR), calorimetria exploratória diferencial (DSC), eletroforese, dosagens de citocinas e síntese de óxido nítrico considerando o fator limitate do uso do látex como um material bioativo, que é a temperatura de tratamento térmico, realizado para a obtenção das membranas de borracha natural, em torno de 85ºC. Foi possível verificar que a fração F3 constituinte do látex, tem propriedades anti-inflamatórias e que a fração F2 possui propriedades pró-inflamatórias
Abstract: Currently it is proven the hability of inducing angiogenesis and tissue neoformating through membranes of natural rubber Hevea brasiliensis, so this work presents a study on the properties and characterization of non-isoprene fractions, separated by centrifugation, the latex used as biomaterial for induction and neoformation of angiongenesis and lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized to reduce the amount of water and stabilization, and then heat treated at temperature of 40, 60, 80, 100, 120 and 140ºC bieng characterized by the techniques of kjeldahl, Soxhlet, of absorption spectroscopy infrared (FT-IR), Nuclear Magnetic Resonance (NMR-13C), X-ray Diffraction (XRD), thermogravimetry (TG) coupled to FT-IR (TG-IR), differential scanning calorimetry (DSC), electrosphoresis, serum cytokines and oxide nitric (NO) considering the limiting factor in the use of latex as a bioactive material, which is the thermal treatment temperature, held for obtaining membranes of natural rubber, about 85ºC. It was possible to verify that the fraction F3 constituent latex has anti-inflammatory and the fraction F2 take inflammatory properties
Doutor
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Clark, L. J., R. Walser, and E. W. Carpenter. "Fall Planted, Late Maturing Onion Variety Trial." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/220391.
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Thirteen late maturing onion varieties were planted in the fall of 1998 and grown in a replicated small plot trial on the Safford Agricultural Center. Bulbs were pulled and the tops removed in early June. Three NuMex varieties, Mesa, Starlite and BR1, produced the best yields. Yields are shown in tabular form together with size distribution and quality characteristics.
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Sow, Demba. "Contribution à l'étude expérimentale et à la modélisation de la digestion anaérobie de Euphorbia tirucalli et d'autres plantes à latex sahéliennes : euphorbia balsamifera et calotropis procera." Châtenay-Malabry, Ecole centrale de Paris, 1993. http://www.theses.fr/1993ECAP0323.
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Le présent travail a consisté à fermenter des plantes à latex pour la production de biogaz. Ainsi, Euphorbia tirucalli, coupé en morceaux ou broyé, est digéré à 37°C puis à 48°C dans différents réacteurs. Les rendements varient de 0,301/l. J a 0,891/l. J. La meilleure productivité en biogaz est obtenue avec la plante coupée en morceaux. La digestion anaérobie de Euphorbia balsamifera et de Calotropis procera, avec des réacteurs de 1,5 l incubés à 37°C puis à 48°C, a donné des rendements variant de 0,30 l/l. J à 0,78 l. J. Notre modèle de simulation de la digestion anaérobie est basé sur l'acétate, le propionate et le glucose. Grâce aux équations mathématiques proposées et aux résultats expérimentaux, nous avons déterminé les constantes des équations. Ainsi, nous avons validé le modèle pour différents fermenteurs de Euphorbia tirucalli.
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Dusotoit-Coucaud, Anaïs. "Caractérisations physiologique et moléculaire des transporteurs de sucres et de polyols des cellules laticifères chez "Hevea brasiliensis", en relation avec la production de latex." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2009. http://tel.archives-ouvertes.fr/tel-00725589.
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L'hévéa est un arbre qui revêt un fort intérêt à l'échelle mondiale. Il représente la seule source de caoutchouc naturel commercialement exploitée. La demande grandissante de cette matière première a conduit à l'initiation de nombreuses recherches visant à augmenter la production de latex. La biosynthèse du caoutchouc à partir du saccharose se déroule dans le cytoplasme (latex) des cellules laticifères, hétérotrophes et dépourvues de plasmodesmes, les cellules laticifères disposeraient d'un équipement membranaire de transporteurs actifs spécifiques, afin de répondre à leurs besoins importants en photoassimilats.Toutefois, le rôle de ces transporteurs dans la physiologie des cellules laticifères n'a jamais été élucidé. Ce travail propose la première étude moléculaire des co-transporteurs H+ / sucres solubles et H+ / polyol (quebrachitol) au sein des cellules laticifères, en relation aves la production de latex. Ce travail a permis l'identification des premiers co-transpoteurs de saccharose d'hexoses et de polyols chez l'hévéa. Dix gènes de trasporteurs ont été clonés dans les cellules laticifères : 7 transporteurs putatifs de saccharose (HbSUT1A, HbSUT B, HbSUT2A, HbSUT2B, HbSUT2C, HbSUT4, HbSUT5), 1 transporteur putatif d'hexoses (HbHXT1) et 2 transporteurs putatifs de polyols (HbPLT1, HbPLT2). Ensuite les caractérisations physiologiques et moléculaires fines de ces transporteurs ont permis la mise en evidence du rôle potentiel et complémentaire de HbSUT1B, HbHXT1et HbPLT2 dans la production de latex, HbSUT1B et HbHXT1 seraient impliqués dans la régulation de la régénération du latex, alors que HbPLT2 interviendrait dans le contrôle de l'écoulement. Ces trois gènes sont proposés en tant que marqueurs moléculaires potentiels de production.
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Titchener, Frederick Robert. "Plant-arthropod interactions in the late Tertiary." Thesis, Royal Holloway, University of London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.482120.
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Rethwisch, M. D., M. Reay, G. Chaffin, R. Perez, J. Grudovich, J. Wellman, and E. Hawpe. "Late Planted DPL451BR Cotton Responses to Plant Growth Enhancement Products Applied at Three Crop Development Stages in Palo Verde Valley, 2003." College of Agriculture, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/198128.
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An experiment to investigate the effects of several plant growth enhancement products (AuxiGro7 WP, FirstChoice7 Bollster, CalMax, FoliGro7 BollSet) on DPL 451BR was conducted in the Palo Verde Valley. The cotton field chosen for this project was planted in April 2003, and flowering and boll/lint production was highly affected by summer heat, therefore product effectiveness was tested under the extreme high temperatures conditions that existed in 2003. Products were applied July 11 (shortly after first bloom), August 1st and/or August 15. Three rates (1, 2, 4 oz./acre) of AuxiGro7 WP were applied at each date, although just a single rate of other products was evaluated. Data collected included plant mapping following the first two application dates as well as lint yield and quality at harvest on October 20-23. Data indicated rate effects for treatments containing AuxiGro7 WP as noted in response to applications on August 1 (retention rates) and August 15 (cotton quality factors). These responses were signficantly different than the untreated check, and were often signficantly different than the Bollster fertilizer treatment itself as though Bollster was also included with AuxiGro7 WP treatments. Although yields for any treatment and the untreated check were not significantly different, previously noted differences for retention for the AuxiGro7 WP treatments may not have been realized due to the high temperatures and extended periods of not only Level 1 but Level 2 stress during the course of the experiment. Cotton values per acre were highest ($609.85/acre) in the 4 oz/acre of AuxiGro7 applied on August 15, due to highest valued lint as a result of micronaire of 5.2 combined with increased fiber strength and fiber length. Application of CalMax resulted in a significant increase in fiber strength following two applications of 4 oz./acre of AuxiGro7 + Bollster, but CalMax following two applications of Bollster did not affect fiber strength when compared with each of the two application treatments. A third application of FoliGro7 BollSet was detrimental for cotton yields and strength compared with only two applications of this product, although both treatment regimens resulted in shorter fibers that were not quite as strong as the untreated check.
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Amara, Imen. "Abiotic stress in plants: Late Embryogenesis Abundant proteins." Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/83820.
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In order to improve our understanding on LEA proteins and their molecular functions in drought tolerance, the present work analyzes in the first place, the composition of LEA subproteomes from Arabidopsis seeds and maize embryos; second, three maize embryo LEA proteins from groups 1, 2, and 3 are analyzed in order to detect functional differences among them and finally, transgenic maize plants over-expressing group 5 “rab28” lea gene are characterized. The following results are presented:
- Chapter 1. Proteomic approach to analyze the composition of LEA subproteomes from
Arabidopsis seeds by mass spectrometry. The main objective was the development and isolation method to obtain enriched LEA populations from Arabidopsis seeds. LEA subproteomes were obtained using an extraction procedure that combines heat stability and acid solubility of LEA proteins. To identify the protein content, we followed two approaches: first, a classical 1D (SDSPAGE) gel-based procedure associated with MS analysis using an electrospray ionization source coupled on-line to liquid chromatography (LC-ESI-MSMS) and second, a gel-free protocol associated with an off-line HPLC and analysis via matrix assisted laser desorption/ionization (LC-MALDI-MSMS).
- Chapter 2. Proteomic analysis of LEA proteins accumulated in maize mature seeds. Identification of LEA protein content by mass spectrometry and selection of three LEA proteins, Emb564, Rab17 and Mlg3, as representatives of groups 1, 2 and 3 for further study. Comparative functional analysis covering different aspects of maize Emb564, Rab17 and Mlg3 proteins, posttranslational modifications, subcellular localization and their properties in in-vitro and in- vivo assays.
- Chapter 3. Characterization of transgenic maize plants expressing maize group 5 rab28 LEA gene under the ubiquitin promoter. Evaluation of Rab28 transcripts and protein levels, phenotype and stress tolerance traits of transgenic plants under drought stress. Investigation of the subcellular localization of transgenic and wild-type Rab28 protein using immunocytochemical approaches.Las proteínas LEA, originalmente fueron descritas en las semillas de algodón; se acumulan en grandes cantidades en estructuras tolerantes a la desecación (semillas, polen) y en tejidos vegetativos sometidos a estrés abiótico, sequía, salinidad y frío. También se hallan en organismos anidrobióticos, en plantas de resurrección, algunos invertebrados y microorganismos. La presencia de proteínas LEA se correlaciona con la adquisición de tolerancia a la desecación. Desde un principio se les atribuyó un papel en las respuestas de las plantas en la adaptación al estrés (revisado en Bartels and Salamini 2001, Tunnacliffe 2007, Shih et al. 2010, Tunnacliffe 2010, Hand et al. 2011). Las proteínas LEA se clasifican en diversos grupos en función de dominios y secuencias de aminoácidos específicos (Wise 2010, Batagglia et al 2008, Bies-Ethève et al 2008). Los grupos 1, 2 y 3 son los más relevantes ya que abarcan la mayoría de las proteínas de la familia LEA. Una característica general de estas proteínas es su elevada hidrofilicidad, alto contenido de aminoácidos cargados y su falta de estructura en estado hidratado. A pesar de encontrarse mayoritariamente en forma de “random coil”, algunas adquieren un cierto grado de estructura durante la deshidratación o en la presencia de agentes promotores de α-hélices (Shih et al. 2010, Hand et al. 2011). A nivel celular se han hallado en todas las localizaciones, citosol, núcleo, nucleolo, mitocondria, cloroplasto, vacuola, retículo endoplásmico, peroxisoma y membrana plasmática, donde se supone ejercen su función protectora frente al estrés (Tunnacliffe and Wise 2007, Hundertmark and Hincha 2008). En relación a las modificaciones post-traduccionales, algunas se hallan fosforiladas (Jiang and Wang 2004; Plana et al. 1991, Heyen et al. 2002, Rohrig et al. 2006). Los efectos protectores de las varias proteínas LEA se han demostrado mediante ensayos in vitro y en aproximaciones transgénicas que han dado lugar a fenotipos resistentes a la sequía, sal y frío. Por lo general, se considera que estas proteínas contribuyen a la protección y a la estabilización de macromoléculas y estructuras celulares en las respuestas de adaptación al estrés en plantas; sin embargo, sus funciones específicas aún no han sido esclarecidas. A nivel molecular se ha propuesto que las funciones de las proteínas LEA pueden ser variadas: estabilización y renaturalización de proteínas, mantenimiento de membranas, en combinación, o no, con azúcares, tampones de hidratación (substitución de moléculas de agua), afinidad por iones y función antioxidante (Tunnacliffe and Wise 2007, Shih et al. 2010, Batagglia et al. 2008). Para finalizar, diremos que los objetivos principales de esta tesis consisten en ampliar los conocimientos sobre las proteínas LEA y sus funciones relativas a la tolerancia a la sequía. Los resultados están presentados en forma de capítulos.
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DiCenzo, Gregory Lawrence. "Elucidation of late steps in pisatin biosynthesis." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282830.
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Many plant species, in response to stresses, accumulate low molecular weight secondary metabolites called phytoalexins. Pea (Pisum sativum ) makes a pterocarpanoid phytoalexin called pisatin which is relatively unique among pterocarpans because its stereochemical configuration is different at two adjacent carbons from the corresponding carbons in pterocarpan phytoalexins synthesized by alfalfa, soybean, clover and other legumes. Previous research demonstrated that an (-) isoflavanone-synthesizing isoflavone reductase (EFR) is induced during (+) pisatin biosynthesis and the final step in the biosynthesis is the methylation of (+) cis-6a-hydroxymaackiain (HMK) by 6a-hydroxymaackiainmethyltransferase (HMM). And, contrary to a predominant model of (+) pisatin biosynthesis, the 6a-OH of pisatin was shown to involve oxygen from H₂O rather than O₂. This work describes the role of (-) isoflavanone (sophorol) in (+) pisatin biosynthesis. Radioactive tracer techniques were used both in vivo and in vitro to analyze metabolism of (-) sophorol and related isoflavonoids. I have found that, in vivo, the incorporation of (-) sophorol into (+) pisatin is more efficient than the incorporation of (+) sophorol and (+) maackiain, suggesting that the normal biosynthetic route to (+) pisatin utilizes (-) and not (+) sophorol and does not use maackiain. (+) Sophorol is not metabolized in vitro by pea protein extracts, although isoflavene, 7,2 '-Dihydroxy-4',5'-methylenedioxyisoflavanol (DMDI) and a novel diastereomer of HMK, trans-HMK, accumulate when (-) sophorol is used as substrate. A cDNA from pea, which encodes sophorol reductase (SOR), was cloned by homology to an alfalfa cDNA coding for isoflavanone reductase. The SOR cDNA was found to be transcribed in response to CuCl₂ treatment of pea seedlings, as was previously found for cDNAs of IFR and HMM, which are involved in pisatin biosynthesis. The SOR cDNA gene product specifically reduces (-) and not (+) sophorol in vitro. DMDI, the product formed by the activity from the recombinant protein, is incorporated in vivo into (+) pisatin. My current model of (+) HMK synthesis proposes that (-) sophorol and (3R) DMDI are normal in vivo pathway intermediates. However, trans-HMK is likely an artifact as it is a poor pisatin intermediate in vivo and is also a poor substrate in vitro for HMM.
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Cambon, Emmanuelle. "Plantes laticifères : mise en évidence et applications des activités lipasiques de Carica pentagona et Plumeria rubra." Montpellier 2, 2008. http://www.theses.fr/2008MON20010.
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À l'heure actuelle, les lipases généralement utilisées dans l'industrie sont d'origine microbienne. Cependant, en raison de leur large disponibilité et de leur possible utilisation sous forme brute, les lipases végétales s'avèrent être des biocatalyseurs prometteurs. Dans cette optique, les activités lipasiques des latex de Carica pentagona et de Plumeria rubra ont été caractérisées. Les tracés des isothermes de sorption du latex de C. Pentagona et la mise en œuvre de ce latex préincubé à différentes aw (activité thermodynamique de l'eau) ont révélé que l'état d'hydratation optimal du biocatalyseur, en réactions de transfert d'acyles, est obtenu pour des couples (aw, teneurs en eau) compris entre (0,33 ; 4,7 %) et (0,44 ; 6,4 %). En parallèle, un phénomène d'hystérèse marqué entre les phases de sorption et de désorption d'eau du latex de P. Rubra complique la détermination de son état d'hydratation optimal en vue de son utilisation dans des réactions de transfert d'acyles. Par la suite, l'extraction partielle des lipases des latex de C. Pentagona et de P. Rubra dans l'hexane a conduit à poser l'hypothèse d'une immobilisation de ces enzymes sur un support naturel par une possible encapsulation dans des vésicules hydrophobes. Enfin, une caractérisation plus poussée du latex de C. Pentagona a permis de mettre en évidence des applications possibles dans des procédés de transformation des huiles et corps gras. D'une part, ce latex est apparu sn-1,3-régioselectif en réaction de lipolyse, et typosélectif, en réactions d'hydrolyse et de transfert d'acyles, des triacylglycérols présentant des acides gras à chaînes courtes et polyinsaturées ; il pourrait alors être valorisé dans la production de triacylglycérols restructurés présentant une valeur nutritionnelle accrue. D'autre part, par le biais de réactions de méthanolyse mises en oeuvre par des ajouts fractionnés de méthanol, le latex de C. Pentagona biocatalyse la dérivation de 70 % des triacylglycérols de l'huile de tournesol en esters méthyliques, ce qui le conduit à être potentiellement utilisable à l'avenir dans des procédés de production d'esters alkyliques déstinés à l'industrie lipochimiqueTo date, the lipases that have been generally used in industry have come from microbial or animal sources. Owing to their large availability and their possible use without any purification, plant lipases may be cheaper biocatalysts. In this study, the lipolytic activities of Carica pentagona and Plumeria rubra latex were identified and characterized in hydrolysis and acyl transfer reactions. Firstly, the influence of thermodynamic water activity on reaction yields in acyl transfer reactions was determined and correlated with the water sorption and desorption isotherms of the latex. With respect to C. Pentagona, the optimal latex hydration state was obtained for the values of the couple (aw, water content) of (0. 33, 4. 7 %) and (0. 44, 6. 4 %). For P. Rubra, a large hysteresis between the moisture sorption and desorption of the latex complicated the evaluation of its optimal hydrate state. Secondly, based on a partial extraction of both latex lipases in hexane, it was suggested that these enzymes are immobilized on a natural hydrophobic support similar to polyisoprens. Attempts to identify this lipase support were conducted and discussed. Finally, the further characterization of C. Pentagona latex as a lipolytic biocatalyst was conducted in order to identify potential applications. On one hand, the biocatalyst appeared to be sn-1,3-regioselective in hydrolysis reactions, and displayed a higher activity on triacylglycerols with short and unsaturated fatty acids. Consequently, this lead to the conclusion that C. Pentagona latex extract could be used in customizing lipids to obtain nutritionally improved triacylglycerols. On the other hand, in methanolysis reactions conducted by adding methanol stepwise, C. Pentagona latex biocatalyzed the conversion of 70 % of sunflower triacylglycerols in methyl esters and thus, may have potential applications in the fabrication of alkyl esters for the lipochemical industry
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Clark, Lee, and Max Thatcher. "Late-Planted Barley Variety Trial, Safford Agricultural Center - 1986." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200571.
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Stevens, Laura J. "Engineering durable late blight resistance to protect solanaceous plants." Thesis, University of Dundee, 2016. https://discovery.dundee.ac.uk/en/studentTheses/27fe2bc9-ac18-4000-a3cf-9bb895cabe3a.
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Phytophthora infestans, the oomycete pathogen responsible for late blight of potato and tomato, is regarded as the biggest threat to global potato production and is thought to cost the industry around £6 billion annually. Traditionally, fungicides have been used to control the disease, but this is both economically and environmentally costly, as multiple chemical applications may be required during a single growing season. P. infestans has rapidly overcome genetic resistances introduced into cultivated potato from wild species. This provides the rationale for developing artificial resistance genes to create durable resistance to late blight disease.Phytophthora species secrete essential effectors into plant cells that target critical host cellular mechanisms to promote disease. One such P. infestans effector is AVR3aKI which is recognised by the potato R3a protein, a member of the CC-NB-LRR type resistance gene family. However, the closely related virulent form, AVR3aEM, which is homozygous in more than 70% of wild P. infestans isolates, evades this recognition. Domain swapping experiments have revealed that the LRR domain of R3a is involved in recognition of AVR3aKI, as the CC-NB domain of an R3a-paralog which does not mediate recognition of AVR3aKI, is able to induce a HR when combined with the LRR of wild-type R3a. However, a chimeric protein consisting of the CC-NB domain of a more distantly-related homolog of R3a and the LRR of domain of R3a, is unable to recognise AVR3aKI, suggesting that function is achieved only when the different domains of an R protein are attuned to recognition and signalling. Gain-of-function variants of R3a (R3a*), engineered by an iterative process of error-prone PCR, DNA fragmentation, re-assembly of the leucine rich repeat (LRR)-encoding region of R3a, are able to recognise both forms of AVR3a. This gain-of-recognition is accompanied by a gain-of-mechanism, as shown by a cellular re-localisation from the cytoplasm to prevacuolar compartments upon perception of recognised effector forms. However, R3a* variants do not confer resistance to AVR3aEM-carrying isolates of P. infestans.Future efforts will target the NB-ARC domain of R3a, in a bid to fine-tune the intra-cellular signalling of gain-of-recognition R3a* variants. It is hoped that a shuffled R3a* gene, capable of conferring resistance to P. infestans isolates harbouring AVR3aEM, will provide durable late blight resistance when deployed in the field in combination with other mechanistically different R proteins.
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Silva, Maria Zelandia Rocha. "Insulation immunoaffinity chromatography and antifungal activity osmotinas of latex fluid." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14503.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorPlants are constantly exposed to a variety of stresses conditions. However, they react to biotic stresses by triggering a set of defense mechanisms including the synthesis of defensive substances as the pathogenesis-related (PR) proteins. The PR-protein named osmotin can be induced under osmotic stress and water shortage conditions. Osmotin-like proteins have been purified from latex and some of them are related to antifungal activity. The aim of this study was to investigate the osmotin in the following species laticifers: C. grandiflora, P. rubra, T. peruviana, H. drasticus and C. papaya to isolate and evaluate its antifungal activities. Immunoaffinity column chromatography with anti-CpOsm antibodies were performed in order to purify these osmotin-like. They were detected in latex of C. grandiflora and P. rubra by immunoassays the ELISA, Dot Blot and Western Blot using anti-CpOsm antibody (the osmotin of C. procera latex). Osmotin of C. procera, C. grandiflora, P. rubra and H. drasticus were identified by mass spectrometry. However, the osmotin from C. procera was co-purified with cysteine proteases. The co-purified cysteine protease from C. procera was identified as Procerain B. The alignment and the 3-D structure analysis of Procerain B and CpOsm revealed the presence of a similar sequence in both proteins. This sequence might be an epitope which allows the anti-antibody recognition. The osmotin from C. grandiflora, and P. rubra did not show antifungal activity against Fusarium solani and Colletotrichum gloesporioides. Since no correlation between the antifungal activity and the presence of these osmotins were found, the proteolytic activities of these latex protein fractions were evaluated in order to correlate with the antifungal activity C. procera and C. grandiflora showed a strong proteolytic activity. In latex, the cysteine proteases are more often related to antifungal activity than osmotin, which might explain, at least in part, the antifungal activity performed by C. grandifora and not for its osmotin. Further studies on the role of osmotin in physiology laticifers plants are needed.
As plantas estÃo constantemente sujeitas a diversos tipos de estresse, tanto biÃticos como abiÃticos, resultando em respostas de defesa. Decorrente disto, os vegetais sintetizam certas proteÃnas denominadas de proteÃnas relacionadas à patogÃnese (PR proteÃna). As Pr-proteÃnas chamadas de osmotinas podem ser induzidas sob condiÃÃes de estresse osmÃtico, frio e escassez de Ãgua. Osmotinas tem sido purificadas de fluidos laticÃferos e algumas delas estÃo relacionadas com a atividade antifÃngica. O objetivo do presente trabalho foi prospectar osmotinas, bem como isolÃ- las e avaliar suas atividades antifÃngicas, nos fluidos laticÃferos das seguintes espÃcies: C. grandiflora, P. rubra, T. peruviana, H. drasticus e C. papaya. Nos lÃtex de C. grandiflora e P. rubra foram detectadas osmotinas atravÃs de imunoensaios em placa de ELISA, Dot Blot e Westen Blot, utilizando os anticorpos anti-CpOsm (osmotina do lÃtex de C. procera). Cromatografia de imunoafinidade em coluna com anticorpos anti-CpOsm foram realizadas com o intuito de purificar estas osmotinas. AnÃlises por meio de espectrometria de massas, revelaram a presenÃa de osmotina em C. procera, C. grandiflora, P. rubra e H. drasticus. No entanto, a osmotina de C. procera foram co-purificadas com proteases cisteÃnicas. A protease cisteÃnica co- purificada no lÃtex de C. procera foi identificada como Proceraina B. O alinhamento e a anÃlise da estrutura tridimensional da Proceraina B e CpOsm revelaram a presenÃa de uma sequÃncia semelhante em ambas as proteÃnas, que pode ser um epÃtopo disponÃvel ao reconhecimento do anticorpo anti-CpOsm. As osmotinas isoladas de C. grandiflora e P. rubra nÃo apresentaram atividade antifÃngica contra F. solani e C. gloesporioides. Desde que nÃo houve correlaÃÃo entre a atividade antifÃngica e à presenÃa destas osmotinas, as atividades proteolÃticas das fraÃÃes proteicas foram avaliadas a fim de correlaciona-las à atividade antifÃngica. Nos fluidos laticÃferos, as proteases cisteÃnicas estÃo mais frequentemente relacionadas à atividade antifÃngica do que as osmotinas. Estudos mais aprofundados sobre a funÃÃo das osmotinas na fisiologia de plantas laticÃferas sÃo necessÃrios.
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Gilbert, Jennie S. "Late-Hercynian volcanism of the Pyrenees." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302843.
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Clayton, Robert Charles. "Integrated control of potato late-blight (Phytophthora infestans)." Thesis, Bangor University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357249.
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Fanning, U. "Late Silurian - Early Devonian plant assemblages in the Welsh borderland." Thesis, Bucks New University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376410.
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King, Sarah Caroline. "Late Palaeozoic wetland plant communities : palaeoecological, palaeobiogeographic and evolutionary significance." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3565/.
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The late Palaeozoic marked the beginnings of fully established, global terrestrial ecosystems as we know them today. Large-scale provinciality of vascular plants had developed by this time, and four global phytogeographic provinces were named, superimposed on the converging Pangaean landmass: Angara (mid-high latitude north), Gondwana (mid-high latitude south), Euramerica (low latitude west) and Cathaysia (low latitude east). The low latitude provinces supported vast swathes of the famous ‘coal swamp’ wetland flora at this time. Delineation of these provinces has never been formally ratified due to most palaeobotanical work being on a local to regional scale, and results of this work being presumed as representative of a wide area. This thesis examines the wetland flora of the most contentious, low latitude provinces, and aims to assess the widely cited proposal of linkage and substantial interchange between Euramerica and Cathaysia. The proposal is upheld, specifically during the Stephanian (~305-300 Ma), when the well established flora in Euramerica migrated along a pathway through the tectonically complex Angara region and quickly colonised North Cathaysia,where it flourished and diversified after the extirpation of the source flora in Euramerica. Connections between the regions at other times are also found to be highly likely,although the complexity of the tectonic backdrop, and difficulties with characterisation of highly dynamic wetland floras, lead to ultimate recommendations to analyse the floras as fully and in as wide a context as possible, and to utilise all avenues of evidence, in order to progress in uncovering their full histories.
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Vouri-Richard, Derek S. "A Spatial Plane of Immanence: American Cinema in Late Capitalism." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1443712775.
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Yates, David Ira. "Latex of Sciadopitys verticillata (Thunb.) Siebold and Zuccarini: Antibiotic Properties, Phytochemistry, and Inhibition of Adventitious Rooting of Stem Cuttings." Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etd/2228.
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Sciadopitys verticillata was subjected to three propagation treatments designed to inhibit coagulation of its latex-like sap at the cut ends of the stem cuttings. Twenty-four hour soaking in water prior to rooting hormone application significantly enhanced production of adventitious roots. Old wood stem cuttings from shade-grown trees rooted at higher proportions than stem cuttings collected from sun-grown trees. Height, age, and place of origin of the source trees were not important factors in successful rooting. Antibacterial activity against some human pathogens and soil bacterial species was detected in latex application trials but the antibiotic activity was not related to the bacterial Gram reaction. The latex-like sap inhibited none of four plant pathogens tested. A suspension of the water insoluble latex-like sap of S. verticillata had a pH of 5.8. Antibacterial activity of S. verticillata sap was heat stable, which indicates the activity was not protein-based.
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DeRosa, Edith, Lee Clark, and David Parsons. "Late Corn Variety Trial, Greenlee County - 1985." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/200574.
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Benedictow, Ole Jørgen. "Plague in the late medieval nordic countries : epidemiological studies /." Oslo : Middelalderforlaget, 1992. http://catalogue.bnf.fr/ark:/12148/cb35552740m.
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Björkblom, Inger. "The Plane of Uncreatedness : A Phenomenological Study of Anita Brookner's Late Fiction." Doctoral thesis, Stockholms universitet, Engelska institutionen, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-21953.
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The investigation maintains that the late fiction of Anita Brookner exhibits an autonomous region of auto-affective experience. This region shapes the materialization of subjectivity in the artifact. The study proposes that the autonomy of the region establishes the ontological nature of Brooknerian reality as a priority of the uncreated over the created. Using Michel Henry's Eckhartian phenomenology of auto-affection as a methodological and philosophic rationale, the study begins by exploring the experience of emptiness and boredom in the late Brookner novels: Lewis Percy, Visitors, Fraud, Falling Slowly, A Closed Eye, Altered States, Undue Influence, Incidents in the Rue Laugier, Brief Lives, A Family Romance, and A Private View. After excluding extrinsic considerations by means of phenomenological reduction, the study investigates the aesthetic and ontological implications furnished by the tension in the late Brookner novel s between autonomous and non-autonomous spheres of phenomenalization. Following the terminological usage set up in the 14th century by the controversial writings of Meister Eckhart, these two spheres are identified as those of the uncreated and the created. This non-dialectical model of phenomenalization, refined in the phenomenology of Michel Henry, is used in the study for the purpose of clarifying the nature of abstraction in the late Brookner novel: it is demonstrated, especially in close readings of Lewis Percy, Visitors and Falling Slowly, that the extreme experiential reduction accomplished in the Brookner novel through ruthless abstraction of subjectivity leaves an experiential remainder which, in so far as it is a plane of emptiness or a plane of uncreatedness, is analogous to the non-figurative frontality forwarded in the paintings and writings of Wassily Kandinsky as the abstract but material origin of a realm of pure worldlessness. The study shows that the latent excitement discovered in the hidden truth of this plane is descriptively graspable in terms of an understanding of a key factor in Brooknerian real ity: the absence of transcendence. Although subjectivity's reality is firmly situated on the hither side of the world, and although that worldless sphere is essentially one of non-difference, subjective life is nevertheless crucially attuned to a sense of the contrast between two modes of non-difference: the empty and the uncreated. However, these two modes are not experienced as transcendent to each other; they are not two different phenomena, and the passing from the one to the other is not a transcending of a phenomenon but a discovery of its depth.
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Stephenson, Jonathan. "Evidence of plant insect interactions in the late Cretaceous and early Tertiary." Thesis, Royal Holloway, University of London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508107.
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Björkblom, Inger. "The plane of uncreatedness : a phenomenological study of Anita Brookner's late fiction /." Stockholm : Almqvist & Wiksell international, 2001. http://catalogue.bnf.fr/ark:/12148/cb39903711g.
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Oliveira, Jefferson Soares de. "MÃltiplas proteÃnas estÃo envolvidas nas atividades antiinflamatÃria e antinociceptiva do lÃtex da planta medicinal Calotropis procera (AIT.) R. Br." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3377.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorA planta Calotropis procera, pertencente à famÃlia Apocinaceae, tem como uma de suas principais caracterÃsticas a produÃÃo constitutiva de lÃtex. Este fluido à amplamente utilizado na medicina popular, principalmente da Ãndia, por apresentar diversas propriedades curativas. Na literatura, o produto da extraÃÃo do lÃtex Ãntegro com solvente aquoso e/ou orgÃnico desta planta à citado por apresentar atividade antinociceptiva e antiinflamatÃria. Por outro lado, a mesma preparaÃÃo do lÃtex tambÃm à relatada por induzir processos inflamatÃrios. O presente trabalho teve como objetivo fracionar o lÃtex da planta Calotropis procera para separar as atividades prÃ- e antiinflamatÃria; caracterizar estes mecanismos e avanÃar na identificaÃÃo das molÃculas envolvidas na atividade antiinflamatÃria e antinociceptiva. O lÃtex coletado em Ãgua destilada (1:1; v/v) foi submetido Ãs etapas de centrifugaÃÃo e diÃlise e trÃs fraÃÃes foram obtidas (FD, PL e B) e inicialmente avaliadas quanto à presenÃa de atividade prÃ- e antiinflamatÃria, utilizando o modelo de peritonite em ratos. A fraÃÃo FD, rica em compostos de massa molecular inferior a 8.000 Da, nÃo se mostrou antiinflamatÃria quando administrada por via endovenosa nos animais. Por outro lado, uma forte atividade prÃ-inflamatÃria foi observada quando esta foi injetada na cavidade peritoneal de ratos. A resposta inflamatÃria induzida por FD foi dependente de tempo e dose e parece estar relacionada com a presenÃa de peptÃdeos detectados na fraÃÃo, jà que esta atividade foi diminuÃda quando a fraÃÃo foi tratada com pronase durante 24 horas antes de sua administraÃÃo nos ratos. A inflamaÃÃo induzida por FD foi inibida por Dexametasona, Talidomida e Meclizina sugerindo um processo inflamatÃrio induzido por vias de liberaÃÃo de histamina e TNF-α. A fraÃÃo PL, rica em proteÃnas, e a fraÃÃo borracha (B) nÃo foram prÃ-inflamatÃrias e apresentaram forte atividade antiinflamatÃria por via endovenosa. A atividade promovida por B parece estar relacionada à presenÃa de proteÃnas pertencentes à fraÃÃo PL, como observado em ensaio de detecÃÃo imunolÃgica. PL inibiu o processo inflamatÃrio induzido por FD. A atividade antiinflamatÃria promovida pela fraÃÃo PL parece ser um evento promovido pela aÃÃo de proteÃnas, visto que a atividade antiinflamatÃria da fraÃÃo foi perdida apÃs aquecimento ou tratamento com pronase, e permaneceu ativa apÃs precipitaÃÃo com acetona. TrÃs novas sub-fraÃÃes (PI, PII e PIII) foram obtidas apÃs aplicaÃÃo da fraÃÃo PL em coluna de troca iÃnica (CM-Sepharose Fast Flow) em pH 5,0. As sub-fraÃÃes, distintas entre si, como observado atravÃs de eletroforese em gel de poliacrilamida, foram igualmente capazes de reverter a inflamaÃÃo induzida por carragenina no modelo de peritonite em ratos, bem como reduzir as contorÃÃes abdominais induzidas por Ãcido acÃtico, evidenciando o envolvimento de mÃltiplas proteÃnas na resposta antiinflamatÃria e antinociceptiva produzida pela fraÃÃo PL. Ensaio de microscopia intravital revelou que PI, PII e PIII inibem o rolamento e a adesÃo leucocitÃria no mesentÃrio de camundongos. Somente PI induziu intensa produÃÃo de Ãxido nÃtrico em ratos alÃm de ter sido a Ãnica sub-fraÃÃo capaz de reverter a resposta prÃ-inflamatÃria promovida pela fraÃÃo FD, evidenciando diferentes mecanismos antiinflamatÃrios promovidos por diferentes proteÃnas do lÃtex. A atividade antiinflamatÃria nÃo foi observada quando a fraÃÃo PL foi administrada por via oral nos animais. Este à o primeiro trabalho que confirma a presenÃa de duas atividades antagonistas no lÃtex de C. procera e que estas sÃo promovidas por molÃculas distintas passÃveis de serem separadas com base em seu tamanho molecular. O conjunto de resultados aqui apresentados mostra que a atividade antiinflamatÃria e antinociceptiva do lÃtex foram promovidas por molÃculas protÃicas
Latex is a general term used to describe fluid exudates from plants after mechanical injury. Latex from Calotropis procera is well known for its medicinal properties mainly in Indian traditional medicine. Moreover, it has been experimentally shown that it exhibits interesting biological activities such as anti-inflammation. However its latex has been reported to induce proinflammatory responses. In the present work, (1) the latex was fractionated to segregate pro- and anti-inflammatory activities; (2) assays were carried out to characterize the mechanism of action of active fractions and (3) attempts were done to identify molecules involved in anti-inflammatory and antinociceptive activities. First, the latex was collected in distilled water (1:1; v/v) and submitted to centrifugation and dialysis steps to obtain three different fractions (FD, PL and B). These fractions were evaluated to pro- and anti-inflammatory activities using peritonitis model in rats. FD, constituted by compounds with molecular mass lower than 8,000 Da, did not exhibited anti-inflammatory activity, however induced intense neutrophil migration into peritoneal cavity of rats. The inflammation induced by FD was time and dose dependent. Moreover, it was seen that previous injection of Dexamethasone, Thalidomide and Meclizine in animals inhibited FD inflammatory responses suggesting that inflammation triggered by this fraction occurs through histamine and TNF-α release. Peptides, present in FD as shown in electrophoresis, should be involved in inflammation responses displayed by FD since such activity was diminished after 24 hour pronase treatment. Fractions PL, and B did not induce inflammatory response when injected into peritoneal cavity of animals, however intravenous injection displayed strong anti-inflammatory activity against inflammation induced by carrageenan. The anti-inflammatory activity promoted by B seems to be related to PL proteins present in B. PL fraction inhibited neutrophil migration trigged by FD. PL anti-inflammatory activity ought to be related to proteins since such activity was completely abolished after heat or pronase treatment and it still remained after acetone precipitation. Three protein sub-fractions (PI, PII and PIII) were recovered after PL chromatography on ion-exchange column (CM-Sepharose Fast flow) at pH 5.0. In spite of the fact that PI, PII e PIII were seen to be different by electrophoresis they were equally able to inhibit neutrophil migration induced by carrageenan in rats as well as abdominal writhes stimulated by acetic acid in mice. Intravital microscopy assay revealed that, PI, PII and PIII inhibit both leucocyte rolling and adhesion in mice mesenteric tissues. In addition, PI was able to induce nitric oxid production and inflammation induced by FD. These results show that multiples proteins in PL display anti-inflammatory activity and they act at different pathway of inflammation. Several experiments were performed aiming to detect the anti-inflammatory activity of PL when it was administered by oral route however, we did not obtain success. This is the first report which confirms the presence of pro- and anti-inflammatory activities and it shows that such activities are displayed by compounds suitable to be fractionated on the basis of their molecular size. In addition, these results show that anti-inflammatory and antinociceptive activities are displayed by proteins present in the latex
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Oliveira, Jefferson Soares de. "Múltiplas proteínas estão envolvidas nas atividades antiinflamatória e antinociceptiva do látex da planta medicinal Calotropis procera (AIT.) R. Br." reponame:Repositório Institucional da UFC, 2009. http://www.repositorio.ufc.br/handle/riufc/18176.
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OLIVEIRA, Jefferson Soares de. Múltiplas proteínas estão envolvidas nas atividades antiinflamatória e antinociceptiva do látex da planta medicinal Calotropis procera (AIT.) R. Br. 2009. 101 f. Dissertação (Mestrado em Bioquímica) - Universidade Federal do Ceará, Fortaleza-CE, 2009.Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-05-25T13:19:57Z No. of bitstreams: 1 2009_dis_jsoliveira.pdf: 2272072 bytes, checksum: 0182fc53b1ceb0d4a37902cd816bcd13 (MD5)
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Latex is a general term used to describe fluid exudates from plants after mechanical injury. Latex from Calotropis procera is well known for its medicinal properties mainly in Indian traditional medicine. Moreover, it has been experimentally shown that it exhibits interesting biological activities such as anti-inflammation. However its latex has been reported to induce proinflammatory responses. In the present work, (1) the latex was fractionated to segregate pro- and anti-inflammatory activities; (2) assays were carried out to characterize the mechanism of action of active fractions and (3) attempts were done to identify molecules involved in anti-inflammatory and antinociceptive activities. First, the latex was collected in distilled water (1:1; v/v) and submitted to centrifugation and dialysis steps to obtain three different fractions (FD, PL and B). These fractions were evaluated to pro- and anti-inflammatory activities using peritonitis model in rats. FD, constituted by compounds with molecular mass lower than 8,000 Da, did not exhibited anti-inflammatory activity, however induced intense neutrophil migration into peritoneal cavity of rats. The inflammation induced by FD was time and dose dependent. Moreover, it was seen that previous injection of Dexamethasone, Thalidomide and Meclizine in animals inhibited FD inflammatory responses suggesting that inflammation triggered by this fraction occurs through histamine and TNF-α release. Peptides, present in FD as shown in electrophoresis, should be involved in inflammation responses displayed by FD since such activity was diminished after 24 hour pronase treatment. Fractions PL, and B did not induce inflammatory response when injected into peritoneal cavity of animals, however intravenous injection displayed strong anti-inflammatory activity against inflammation induced by carrageenan. The anti-inflammatory activity promoted by B seems to be related to PL proteins present in B. PL fraction inhibited neutrophil migration trigged by FD. PL anti-inflammatory activity ought to be related to proteins since such activity was completely abolished after heat or pronase treatment and it still remained after acetone precipitation. Three protein sub-fractions (PI, PII and PIII) were recovered after PL chromatography on ion-exchange column (CM-Sepharose Fast flow) at pH 5.0. In spite of the fact that PI, PII e PIII were seen to be different by electrophoresis they were equally able to inhibit neutrophil migration induced by carrageenan in rats as well as abdominal writhes stimulated by acetic acid in mice. Intravital microscopy assay revealed that, PI, PII and PIII inhibit both leucocyte rolling and adhesion in mice mesenteric tissues. In addition, PI was able to induce nitric oxid production and inflammation induced by FD. These results show that multiples proteins in PL display anti-inflammatory activity and they act at different pathway of inflammation. Several experiments were performed aiming to detect the anti-inflammatory activity of PL when it was administered by oral route however, we did not obtain success. This is the first report which confirms the presence of pro- and anti-inflammatory activities and it shows that such activities are displayed by compounds suitable to be fractionated on the basis of their molecular size. In addition, these results show that anti-inflammatory and antinociceptive activities are displayed by proteins present in the latex
A planta Calotropis procera, pertencente à família Apocinaceae, tem como uma de suas principais características a produção constitutiva de látex. Este fluido é amplamente utilizado na medicina popular, principalmente da Índia, por apresentar diversas propriedades curativas. Na literatura, o produto da extração do látex íntegro com solvente aquoso e/ou orgânico desta planta é citado por apresentar atividade antinociceptiva e antiinflamatória. Por outro lado, a mesma preparação do látex também é relatada por induzir processos inflamatórios. O presente trabalho teve como objetivo fracionar o látex da planta Calotropis procera para separar as atividades pró- e antiinflamatória; caracterizar estes mecanismos e avançar na identificação das moléculas envolvidas na atividade antiinflamatória e antinociceptiva. O látex coletado em água destilada (1:1; v/v) foi submetido às etapas de centrifugação e diálise e três frações foram obtidas (FD, PL e B) e inicialmente avaliadas quanto à presença de atividade pró- e antiinflamatória, utilizando o modelo de peritonite em ratos. A fração FD, rica em compostos de massa molecular inferior a 8.000 Da, não se mostrou antiinflamatória quando administrada por via endovenosa nos animais. Por outro lado, uma forte atividade pró-inflamatória foi observada quando esta foi injetada na cavidade peritoneal de ratos. A resposta inflamatória induzida por FD foi dependente de tempo e dose e parece estar relacionada com a presença de peptídeos detectados na fração, já que esta atividade foi diminuída quando a fração foi tratada com pronase durante 24 horas antes de sua administração nos ratos. A inflamação induzida por FD foi inibida por Dexametasona, Talidomida e Meclizina sugerindo um processo inflamatório induzido por vias de liberação de histamina e TNF-α. A fração PL, rica em proteínas, e a fração borracha (B) não foram pró-inflamatórias e apresentaram forte atividade antiinflamatória por via endovenosa. A atividade promovida por B parece estar relacionada à presença de proteínas pertencentes à fração PL, como observado em ensaio de detecção imunológica. PL inibiu o processo inflamatório induzido por FD. A atividade antiinflamatória promovida pela fração PL parece ser um evento promovido pela ação de proteínas, visto que a atividade antiinflamatória da fração foi perdida após aquecimento ou tratamento com pronase, e permaneceu ativa após precipitação com acetona. Três novas sub-frações (PI, PII e PIII) foram obtidas após aplicação da fração PL em coluna de troca iônica (CM-Sepharose Fast Flow) em pH 5,0. As sub-frações, distintas entre si, como observado através de eletroforese em gel de poliacrilamida, foram igualmente capazes de reverter a inflamação induzida por carragenina no modelo de peritonite em ratos, bem como reduzir as contorções abdominais induzidas por ácido acético, evidenciando o envolvimento de múltiplas proteínas na resposta antiinflamatória e antinociceptiva produzida pela fração PL. Ensaio de microscopia intravital revelou que PI, PII e PIII inibem o rolamento e a adesão leucocitária no mesentério de camundongos. Somente PI induziu intensa produção de óxido nítrico em ratos além de ter sido a única sub-fração capaz de reverter a resposta pró-inflamatória promovida pela fração FD, evidenciando diferentes mecanismos antiinflamatórios promovidos por diferentes proteínas do látex. A atividade antiinflamatória não foi observada quando a fração PL foi administrada por via oral nos animais. Este é o primeiro trabalho que confirma a presença de duas atividades antagonistas no látex de C. procera e que estas são promovidas por moléculas distintas passíveis de serem separadas com base em seu tamanho molecular. O conjunto de resultados aqui apresentados mostra que a atividade antiinflamatória e antinociceptiva do látex foram promovidas por moléculas protéicas
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Yin, Wenzhe. "Arabidopsis MS1 functions as a hub in the transcriptional regulatory network of late tapetum development." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/43214/.
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The development of the pollen grains within the anther locule relies upon the nourishing and secretory properties of a tissue layer termed tapetum. The transition of the post-meiotic phase of tapetum development depends on the MALE STERILITY 1. In the ms1 mutant tapetum development is arrested post-meiosis and lacks subsequent biological processes, such as biosynthesis and secretion of pollen wall/coat components and the tissue programmed cell death process. MS1 exhibits a transient expression pattern, which is tightly regulated and critical for tapetum development and viable pollen formation. Therefore, understanding the genetic control of MS1 is key to uncover the regulation of post-meiotic tapetum development. During this project, three regulation levels of MS1 were studied: (i) transcriptional activation, (ii) auto-repression and (iii) post-translational proteolysis. Phylogenetic footprinting analysis and molecular promoter dissection was used to investigate the transcriptional control of expression and a distal upstream sequence (−2900 to −2066 bp) was found to be essential for the activation of MS1. Three evolutionarily conserved non-coding sequences (CNS), enriched with unusually long consensus motifs, and binding site combinations of MS1 upstream transcription factors (TFs) were found within the −2 kb MS1 upstream sequence. These may serve as essential cis-regulatory elements (CREs) for MS1 expression. ChIP experiments were used to investigate MS1 autorepression; the MS1 protein was shown to bind to the second exon of its genomic locus and to repress its own expression. Post-translational proteolysis was investigated using a triple mutant of the MS1 interacting gene that encodes for an E3 ubiquitin ligase LRB1 and its two paralogs LRB2 and LRB3; which exhibits a novel tapetum phenotype that may be induced by altered removal of MS1 protein in the lrb123 tapetum. The MS1 protein possesses a Plant Homeotic Domain (PHD) finger and belongs to a plant-specific C-terminal PHD contained protein (CPCP) family. Although extensive research has been carried out on the tapetum regulation role of MS1, very little is known about the underlying molecular mechanism. A series in-silico comparative analysis of the CPCP sequences in this thesis found that this family originated from green algae. Besides the PHD, two evolutionarily conserved domains, termed MS1/MMD1 Associated Domain 1 (MAD1) and MAD2, were identified in the protein. Molecular modelling of the MS1 PHD domain predicted a histone reader role with high affinity to H3K4me2/3 histone peptides. Super-resolution STED confocal observation showed that subnuclear localisation of the MS1 protein is distinctive with canonical TFs and aggregates at rounded speckles that resemble Polycomb bodies. A meta-data-analysis of MS1 microarrays found that most MS1 immediately responding genes are repressed by MS1, which is on the contrary to the previously proposed activator role of MS1. MS1 may therefore be a unique plant-specific histone reader family protein that participates in gene repression as a co-repressor. MYB99 has previously been hypothesised to be a direct target of MS1, regulating late tapetum development. Comprehensive phenotyping was carried out on two MYB99 null alleles; however, no defects were identified, probably due to high function redundancy among the MYB family TFs. In addition, no evidence of direct activation by MS1 was observed by yeast one-hybrid and ChIP analysis. Interestingly, a PCD indicator gene was down-regulated in the myb99 mutant, suggesting a tapetal PCD regulatory role for MYB99.
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Hobbs, Richard. "Late Roman precious metal deposits, c. AD 200-700 : changes over time and space." Thesis, University College London (University of London), 1997. http://discovery.ucl.ac.uk/1317814/.
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This thesis draws together more than 1,800 deposits of late Roman precious metals, namely coins, plate, jewellery, and bullion items, over a 500 year period (c. AD200- 700). Deposits from both West and East of the Empire, and beyond the frontiers, are included. Comparisons between these finds are made by focusing on three main aspects: spatial distribution, size, and date range of items within finds, by dividing the material into 22 deposition phases. A methodology has been developed allowing the size of each find to be compared, regardless of its internal structure and precious metal content (i.e. gold or silver), by assigning each find an Equivalent Gold Weight. Hence it is made possible to compare, for instance, a deposit of base metal silver coinage with a deposit of church silver plate, at least in terms of size, which previously has not been attempted. Past approaches to the interpretation and presentation of these finds are examined, with the aim of this research being to move away from traditional foci of study, namely the internal structure of hoards, epigraphy and iconography, and towards producing a background picture on a far broader level, chronologically and spatially. The deposition phases are surveyed in isolation, and then compared: changes in the focus of deposition activity are thus highlighted. The value of the approach adopted by this study with regard to our understanding of late Roman precious metal deposition is tested by comparing the recent late Roman find from Patching, West Sussex, with the database. Previous theoretical interpretations of hoard deposition are examined in the light of this body of evidence, for example, the question of the relationship between hoarding and social unrest, and the evidence for social traditions of deposition and ritual use of material in different areas within the study region. Finally, other areas of potentially productive future research, in addition to the themes explored in the previous chapters, are discussed.
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Kuswanhadi. "Isolement et caractérisation des gènes ACS et ACO impliqués dans la biosynthèse de l’éthylène chez Hevea brasiliensis : évaluation de leur rôle dans la production de caoutchouc naturel." Montpellier 2, 2006. http://www.theses.fr/2006MON20201.
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Camp, Ann Elizabeth. "Predicting late-successional fire refugia from physiography and topography /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/5556.
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Harwood, Eric D. "Improving the yields of late-planted winter wheat with seeding rate and phosphorus fertility." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/e_harwood_120309.pdf.
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Thesis (M.S. in soil sciences)--Washington State University, December 2009.Title from PDF title page (viewed on Jan. 25, 2010). "Department of Crop and Soil Sciences." Includes bibliographical references.
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Gomez-Alpizar, Luis E. "Molecular Evolution of Phytophthora infestans (Mont.)de Bary, the late blight pathogen." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-11302004-224228/.
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Phytophthora infestans (Mont.) de Bary causes late blight of potato and tomato and is one of the world?s most devastating plant diseases. P. infestans left its footprint in human history when, in the 19th century, it was responsible for the Irish Potato Famine. Nuclear and mitochondrial DNA variability was used to examine the population history of P. infestans. DNA sequence data from three nuclear regions (Intron Ras, Ras, and â-tubulin) and two mitochondrial regions (P3 and P4) were obtained from ninety isolates from various locations including Brazil, Bolivia, Ecuador, Peru, Costa Rica, Mexico (Toluca Valley), the USA and Ireland. Population summary statistics show that the Mexican population from the presumed center of origin of P. infestans, harbored less nucleotide and haplotype diversity than South American populations, and was genetically differentiated from other populations, particularly at the mitochondrial loci. Coalescent-based genealogies of mitochondrial (rpl14, rpl5, tRNAs, cox1) and nuclear (Intron Ras+Ras) loci were congruent and demonstrated the existence of two lineages leading to the present day haplotypes of P. infestans associated with potatoes. A third lineage, associated with a group of isolates from Solanum tetrapetalum collected in the Andean Highlands of Ecuador was also found. In the mitochondrial genealogy the two potato lineages corresponded to the mitochrondrial haplotypes Type I and Type II described elsewhere. Mitochondrial haplotypes were associated with different nuclear backgrounds. Haplotypes found in the Toluca Valley population were derived from only one of the two lineages in both mitochondrial and nuclear genealogies, whereas haplotypes found in South American populations (Peru and Ecuador) were derived from both lineages. Haplotypes found in USA and Ireland populations were also derived from both lineages and these populations were not genetically differentiated from the Peruvian populations, suggesting a common ancestry among these populations. Evidence for recombination was found for Mexican and USA populations. Solanum tetrapetalum isolates were highly polymorphic within the regions analyzed and may be a new species. The results support a South American origin of P. infestans and are discussed in relation of previous hypotheses regarding the geographic origin of this plant pathogen.
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Chiew, Ivan Kar Mun. "Resistant starch from underutilised legumes as prebiotic and its effect on the growth of Danio rerio and Lates calcarifer." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/51752/.
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Aquaculture is an important protein source for Malaysia. However, the susceptibility of fish to disease leads to heavy losses and hinders production. A potential solution is the supplementation of diets with prebiotics: non-digestible carbohydrates which improve growth and health by modulating gut microbiota to favour beneficial bacteria. Resistant starch (RS) is a prebiotic commonly fed to terrestrial animals, but little work has been performed on aquatic animals. Therefore, this study investigated the use of RS isolated from underutilized crops as a prebiotic in fish. Six species of underutilised legumes (adzuki beans, mung beans, black-eyed peas, pigeon peas, Bambara groundnuts and red lentils) were used for starch isolation via alkaline steeping, followed by processing involving enzyme or acid hydrolysis, and lastly gelatinisation and retrogradation to increase RS yield. Starch was isolated with yields of 25 – 40%, while enzyme hydrolysis pre-treatment was more effective and improved RS content up to 18.06% in most legumes. The starch and RS samples were then supplemented at 5% (w/v) in nutrient broth to investigate their prebiotic effect on fish gastrointestinal lactic acid bacteria. Enzyme pre-treatment improved the growth of W. cibaria, L. garvieae and E. gilvus by up to 43.9% for most legumes tested. Red lentil and adzuki bean enzyme-RS showed highest prebiotic potential and was applied in the zebrafish growth trial, while only red lentil was used in the Asian sea bass growth trial. Supplementation of diets with RS from legumes provided no significant difference in the growth and performance parameters measured in both zebrafish and Asian sea bass when supplemented at 2.5% and fed for five and six weeks respectively. Further studies involving analysis of immune parameters is necessary to identify prebiotic potential on targeted fish. Nevertheless, this study contributed to promote future work in using underutilised legumes as prebiotic source to improve the fish health under commercial conditions of rearing.
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Huet, Joëlle. "Etude structurale relative au protéome présent dans les cellules laticifères de Carica papaya." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210052.
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Le latex de Carica papaya est un milieu riche en cystéine protéinases. Celles-ci ont été régulièrement utilisées en cosmétique ou pour l’attendrissement de la viande. Mais ces protéines ont aussi un intérêt pharmaceutique. En effet, le latex est bien connu pour posséder une activité antifongique mais aussi une activité anthelminthique. Ces effets sont régulièrement attribués aux cystéine protéinases qui se trouvent en concentration importante dans le latex. Malgré ces concentrations importantes en protéinases, d’autres protéines restent actives dans ce milieu. C’est le cas de la glutamine cyclase, qui a été extraite intacte de ce milieu et cristallisée. Sa structure nous a révélé une architecture particulière en ‘’&61538;-propeller‘’ à cinq pales avec double fermeture. Cette structure lui confère sa très grande stabilité. Les industries pharmaceutiques sont aussi à la recherche de protéines très stables et résistantes aux protéinases endogènes. Nous avons donc entrepris l’étude du protéome de Carica papaya afin de mettre en évidence d’autres protéines minoritaires relativement stables pouvant conférer au latex son activité anthelminthique. Cette analyse a permis la mise en évidence de différentes protéines appartenant à diverses familles des « pathogenesis related protéins » (PR-proteins): une &61538;-1,3 glucosidase, une analogue à la barwin, une thaumatine et deux chitinases.
Nous nous sommes particulièrement intéressés à ces deux dernières au cours de cette thèse. Une caractérisation de ces deux protéines a permis de montrer que celles-ci étaient bien deux protéines distinctes, identifiées comme chitinases majeure et mineure selon leur abondance dans le latex. Elles sont relativement stables et résistantes à la protéolyse. Une analyse de la séquence de la chitinase majeure a montré que celle-ci était homologue à la chitinase issue de l’orge et une analyse de sa structure révèle la présence d’une grande concentration en prolines localisées principalement dans les neuf boucles de sa structure. Cela pourrait expliquer sa grande résistance vis à vis des cystéine protéinases.
La cristallisation de cette même chitinase en présence de N-acétyl-glucosamine comme additif, a conduit à une structure contenant trois molécules de GlcNac, deux dans le centre actif de notre protéine et une participant au réseau cristallin. Aucune structure de chitinase n’avait encore pu être obtenue en co-cristallisation avec un substrat. A partir des deux GlcNac observés dans le centre actif, nous avons reconstruit un complexe chitinase/(GlcNac)4. L’analyse de ce complexe a permis de mettre en évidence de nouvelles interactions entre (GlcNac)4 et les acides aminés du centre actif ainsi que de confirmer le mécanisme de la famille GH 19.
Des tests préliminaires sur nématodes ont finalement confirmé l’activité anthelminthique du latex et montré que la chitinase pouvait aussi être un bon nématocide
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Wang, Guangyao (Sam), Mario Gutierrez, Michael J. Ottman, and Kelly Thorp. "Durum wheat yield prediction at flowering stage for late N management." College of Agriculture, University of Arizona (Tucson, AZ), 2010. http://hdl.handle.net/10150/203775.
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Managing late N application effectively in durum wheat is important to reach desirable protein content. Yield prediction at anathesis is needed to estimate N requirement for the crop and N application rate. In this project, we use canopy reflectance and image processing, measured at anthesis, to estimate yield at harvest. Our results of the growing season 2009-2010 suggested that the canopy reflectance index ‘NWI-4’ and the spike pixel size obtained from image processing at anthesis are potential approaches to predict durum wheat yield at harvest. The final goal of this research is to find a simple and rapid method to manage late N fertilizer to reach desirable grain protein content.
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Widmark, Anna-Karin. "The late blight pathogen, Phytophthora infestans : interaction with the potato plant and inoculum sources /." Uppsala : Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, 2010. http://epsilon.slu.se/201002.pdf.
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Church, M. J. "Plants and people in the later prehistoric and Norse periods of the Western Isles of Scotland." Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/24455.
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The first millennia BC and AD were a key period in the settlement history of Atlantic Scotland. There is a dramatic increase in the number and diversity of archaeological monuments, many of which are domestic in nature. The sites contain thousands of ecofacts and artefacts, allowing detailed insights into the workings and developments in everyday life across many different sites for the first time. The use of plants by humans would have been an essential component in many of these developments. Prior to this study, little direct evidence for human/plant interactions was available in the Western Isles, a pivotal location in the wider North Atlantic realm. The research focuses analysing and interpreting new carbonised plant macrofossil assemblages from nine multi-period sites in Lewis, the largest island in the Western Isles. A regional sampling strategy was employed, allowing direct statistical comparison of the archaeobotanical remains. Due consideration is given to the taphonomy of the carbonised plant assemblages. A generic model is proposed for most remains, involving the carbonisation of the plant material on household fires, followed by the spread of the ash and the carbonised material across the sites by various anthropogenic and natural transforms. Measurement of the mineral magnetic signatures of on-site sediments supports this model, highlighting both the distribution of ash and its correlation with macrofossil concentration in the stratigraphy. A new technique was also developed, using mineral magnetic measurements of experimental fire ashes to source the fuels used in the household fires. Application of this technique to ash from the archaeological sites indicated that well-humified peat was the principal fuel employed. Four interpretative research themes relating to the use of plants are then addressed. These include the arable economy, the management and procurement of wood and timber, the deliberate gathering of plants and the social dimension of plant use. Integration of these research themes resulted in the construction of a generic annual cycle of the human/plant interaction, requiring sophisticated systems of social co-operation, territoriality and land-division. Comparative analysis demonstrates that the cycle varied over time and space and also changed subtly over the wider region. Finally, various aspects of the cycle are highlighted with regard to the broader social developments occurring during the first millennia BC and AD.
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McCarron, Joseph John. "Evolution and tectonic implications of late Cretaceous - early Tertiary fore-arc magmatism : Alexander Island, Antarctica." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389878.
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Lavagi, Irene. "Transport of proteins and polysaccharides between the late Golgi and the plasma membrane in plants." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.530826.
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Valamoti, Soultana Maria. "Plants and people in late Neolithic and early Bronze age Northern Greece : an archaeobotanical investigation /." Oxford : Archaeopress, 2004. http://catalogue.bnf.fr/ark:/12148/cb39228431p.
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Ottman, Michael J., Michael D. Sheedy, and Richard W. Ward. "Can Yield of Late-planted Small Grains be Compensated by Water and Nitrogen Rates, 2016?" College of Agriculture, University of Arizona (Tucson, AZ), 2016. http://hdl.handle.net/10150/625422.
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8 pp.Wheat and barley are often planted later than optimum due to the timing of the previous crop or to reduce the risk of frost damage. It may be possible to partially compensate for lower yield potential of late plantings by increasing water and nitrogen rates beyond what would have an effect at more optimal plantings. The objective of this study is to evaluate the effects of nitrogen and water rates on late planted wheat and barley. A trial testing water and nitrogen rates for small grains planted late and at the optimal time was established at the Maricopa Ag Center. The experimental design was a split-split plot with main plots as input levels of water and nitrogen (low, medium, and high), subplots as varieties (Tiburon durum and Chico barley), sub-subplots as planting dates (15 December 2015 and 1 February 2016, and 3 replications. In this study, higher levels on inputs of water and nitrogen did not increase yield at later planting dates as we hypothesized. In fact, the highest yields were obtained at medium inputs of water and nitrogen regardless of planting date. The yields of the later planting date were not depressed as we expected due to unusually mild temperatures later in the spring which favored a later planting date this season.
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Wang, Guangyao (Sam), Michael Ottman, and Kelly Thorp. "Late N management in durum wheat using crop models and canopy reflectance." College of Agriculture, University of Arizona (Tucson, AZ), 2012. http://hdl.handle.net/10150/211156.
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Optimizing late N applications in durum wheat is highly needed to obtain adequate protein levels without affecting grain yield. A simple and rapid method for estimating crop yield at flowering stage and crop N status is required to make immediate N application decisions for increasing grain protein content. There were significant differences in grain yield and grain protein among N treatments and durum varieties. Using information on soil properties, weather data, crop management, and variety growth, DSSAT crop model predicted durum grain yield accurately. Canopy reflectance index NDVI at flowering time were closely correlated with crop yield and protein content. The results indicate the potential of using crop models and canopy reflectance index in durum wheat yield prediction and N management.
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Ottman, M. J., T. A. Doerge, and E. C. Martin. "Late Season Water and Nitrogen Effects on Durum Quality, 1995 (Preliminary)." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/201443.
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Durum grain quality is affected by many factors, but water and nitrogen are factors that the grower can control. The purpose of this research was to determine 1) the nitrogen application rate required at pollen shed to maintain adequate grain protein levels if irrigation is excessive or deficient during grain fill and 2) if nitrogen applications during grain fill can elevate grain protein. Field research was conducted at the Maricopa Agricultural Center using the durum varieties Duraking, Minos, and Turbo. The field was treated uniformly until pollen shed when nitrogen was applied at rates of 0, 30, and 60 lbs /acre. During grain fill, the plots were irrigated based on 30, 50, or 70% moisture depletion. In a separate experiment, nitrogen fertilizer was applied at a rate of 30 lbs N /acre at pollen shed only, pollen shed and the first irrigation after pollen shed, and pollen shed and the first and second irrigation after pollen shed. Irrigation had no effect on grain protein level, although increasing nitrogen rates at pollen shed from 0 to 30 and 30 to 60 lbs N /acre increased protein by 1 percentage point. Nitrogen fertilizer application at the first irrigation after pollen shed increased grain protein content from 10.4 to 11.4% and application at the first and second irrigation after pollen shed increased grain protein content further to 11.9% averaged over varieties. Irrigation management during grain fill may not play as large a role in controlling grain protein content as was originally thought except perhaps on heavy soils, and nitrogen fertilizer application during grain fill may not be too late to increase grain protein content.
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Jaime-Garcia, Ramon 1959. "The spatial and temporal analysis of Phytophthora infestans genetic diversity and its influence on late blight epidemics at a regional scale." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288801.
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The temporal and spatial population genetics of Phytophthora infestans, the causal agent of the potato and tomato late blight, was analyzed in a mixed potato and tomato production area in the Del Fuerte Valley, Sin., Mexico. Isolates of P. infestans were characterized by mating type, allozyme analysis at the glucose-6-phosphate isomerase (GPI) and peptidase (PEP) loci, restriction fragment length polymorphism (RFLP) with probe RG57, metalaxyl sensitivity, and aggressiveness to tomato and potato. Spatial patterns of P. infestans genotypes were analyzed using Geographical Information Systems (GIS) and Geostatistics during the seasons 1994-1995 to 1996-1997. A temporal analysis of the P. infestans genetic structure from 1990-1991 to 1996-1997 suggests an asexual or clonal population with frequent introductions from outside the valley. In the period from 1990-1991 to 1994-1995, the A2 mating type was predominant in both tomato and potato crops, with a very low frequency of the A1 mating type occurring either on tomato or on potato. Conversely, by the 1995-1996 season the predominant mating type was the A1, with low frequency of the A2 on tomato. By 1996-1997 only the A1 mating type was found. This suggests sexual reproduction is unlikely to be occurring in this area. Genotype variation, based on mating type, allozymes, and RFLP was, in general, very low with one predominant genotype affecting both crops each year. These predominant genotypes were highly aggressive to both tomato and potato in an in vitro detached leaf aggressiveness test. Other genotypes found on either potato or tomato, but not on both hosts, were non-aggressive to either tomato or potato. Data on metalaxyl sensitivity indicates that allozyme analysis can accurately discriminate between sensitive and resistant isolates. RFLP analysis showed that, in 1995-1996, there was greater diversity than could be determined by allozyme analysis alone. Spatial analysis of the genetic structure of P. infestans indicates that geographic substructuring of this pathogen does occur in this area. Maps displaying the probabilities of occurrence of mating types and genotypes of P. infestans, and of disease severity in a regional scale were obtained. Some genotypes, which exhibited differences in epidemiologically important features such as metalaxyl sensitivity and aggressiveness to tomato and potato, had a restricted spread and were localized in separated areas. Analysis of late blight severity demonstrates recurrent patterns such as the early onset of the disease in the area where both potato and tomato are growing, strengthening the hypothesis that infected potato tubers are the main source of primary inoculum. The information that geostatistics can provide together with the power of GIS and molecular biology techniques can help improve management programs for late blight in the Del Fuerte Valley.
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Wilson, Dale 1972. "Early-flowering mutants of a late-flowering ecotype of Arabidopsis thaliana." Monash University, Dept. of Biological Sciences, 2001. http://arrow.monash.edu.au/hdl/1959.1/8976.
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Rethwisch, Michael D., Jessica Grudovich, Steven Bennett, and Mark Reay. "Evaluation of Various Insecticides for Late Winter/Early Spring Insect Control, 2004." College of Agriculture, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/203838.
Full textAbstract:
Nine insecticides were applied on March 10, 2004, to alfalfa that had been water stressed prior to irrigation on March 6. These actions were thought to have resulted in treatments means with less distinct differences than usually noted for these treatments at 7-14 days post treatment. All pyrethroid treatments as well as Lorsban® and Steward® treatments resulted in significant reductions of alfalfa weevil larvae at four days post treatment. The Trilogy® treatment did not result in acceptable control of this pest. Significant increases in adult alfalfa weevils were noted at 10-14 days post treatment in pyrethroid treated alfalfa, perhaps due to increased production of certain plant volatiles in response to this class of insecticides. Low numbers of blue alfalfa aphids were noted in this study partially due to insecticide control as well as numerous beneficial insects. Fewest damsel bugs were noted from alfalfa treated with MustangMAXTM and Warrior® insecticides.
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Viana, Carolina de AraÃjo. "CaracterizaÃÃo bioquÃmica e atividades biolÃgicas de quitinases laticÃferas de Calotropis procera." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15513.
Full textAbstract:
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorCalotropis procera à uma planta laticÃfera, pertencente à famÃlia Apocynaceae. ProteÃnas de defesa foram descritas no lÃtex com atividade contra insetos fitÃfagos e fungos fitopatogÃnicos. A fraÃÃo proteica do lÃtex tambÃm apresenta atividades farmacolÃgicas, dentre tais efeito citotÃxico seletivo em cÃlulas carcinogÃnicas. A partir da fraÃÃo proteica efetiva sobre cÃlulas neoplÃsicas, o trabalho teve por meta central identificar proteÃna(s) citotÃxica(s) e proceder a sua caracterizaÃÃo bioquÃmica, biolÃgica e suas perspectivas biotecnolÃgicas. As proteÃnas solÃveis do lÃtex (PL) foram fracionadas em matriz de troca iÃnica e a fraÃÃo proteica detentora da citotoxicidade foi refracionada em outra matriz de troca iÃnica (Mono-Q) acoplada a sistema de mÃdia pressÃo. P4 foi identificado como a fraÃÃo citotÃxica, apresentando uma IC50 de 2,2, 1,2 e 2,9 Âg/mL para as linhagens celulares HCT-116, Ovcar-8 e SF-295, respectivamente. A anÃlise proteÃmica da fraÃÃo citotÃxica por eletroforese bidimensional permitiu identificar 15 spots, contendo proteÃnas Ãcidas (pI entre 4 e 6) e com massa molecular aparente de 30 kDa. Quando avaliados por espectrometria de massas todos esses spots foram identificados como quitinases e apresentaram massa intacta de 27,4 kDa. A amostra reagiu positivamente ao reagente de Schiff, sugerindo glicosilaÃÃes. O teor de carboidratos foi estimado em 12,8%. A sequÃncia amino terminal obtida (1QPVMNLEYPRYLNDINDYRDDNNYD28) revelou 50% de similaridade com quitinases de Solanum lycopersicum, Oryza sativa, Nicotiana tomentosiformes dentre outras. As enzimas apresentaram forte atividade quitinolÃtica, com pH Ãtimo variando entre 5-6 e temperatura Ãtima de 25 ÂC. A atividade quitinolÃtica foi reduzida quando tratada com concentraÃÃes crescentes de DTT (3, 10 e 30 mM) o que sugere a presenÃa de pontes dissulfeto estabilizadoras da enzima. AnÃlises por dicroÃsmo circular indicam a presenÃa majoritÃria de alfa-hÃlices na estrutura e que as isoformas se mostraram pouco resistentes a variaÃÃes de temperatura e pH. Imagens de alta resoluÃÃo geradas por microscopia de forÃa atÃmica sugeriram homogeneidade na amostra e um arranjo hexamÃrico foi evidenciado. As quitinases nÃo inibiram o crescimento micelial dos fungos fitopatogÃnicos Fusarium oxysporum e Colletotrichum gloeosporioides, mas reduziram a germinaÃÃo de esporos de C. gloeosporioides. Em consonÃncia as quitinases nÃo induziram estresse oxidativo nos esporos, mas causaram leves alteraÃÃes na permeabilidade membranar dos esporos avaliados. As quitinases laticÃferas (0,1 % m/m) apresentaram forte efeito deletÃrio sobre o inseto fitÃfago Callosobruchus maculatus. Os efeitos produziram 57% de reduÃÃo na sobrevivÃncia larval, reduÃÃo do peso de larvas (7,8 mg  0,2 /4,0  0,8) e emergÃncia de insetos adultos (50%), alÃm de prolongar de 28 para 33 dias o tempo mÃdio de desenvolvimento de insetos adultos. As quitinases (2 mg/Kg, e.v.) apresentaram forte atividade anti-inflamatÃria, reduzindo em 95% a infiltraÃÃo de neutrÃfilos na cavidade peritoneal em ensaio de inflamaÃÃo induzido por carragenina em camundongos. Este efeito foi revertido por L-NAME e Aminoguanidina, dois inibidores da enzima Ãxido nÃtrico sintase, indicando o possÃvel envolvimento do Ãxido nÃtrico no efeito observado. Esta aÃÃo foi associada à reduÃÃo dos nÃveis das citocinas prÃ-inflamatÃrias TNF-α e IL-1 na cavidade peritoneal e do aumento dos nÃveis sÃricos das citocinas prÃ-inflamatÃrias TNF-α, IL-6 e IL-1. à concluÃdo que vÃrias isoformas de quitinases coexistem no lÃtex de C. procera. Estas proteÃnas atuam possivelmente na defesa contra insetos, mas tÃm pouca aÃÃo contra fungos. As quitinases laticÃferas foram identificadas como as proteÃnas citotÃxicas do lÃtex sobre cÃlulas neoplÃsicas e ainda foram capazes de modular os nÃveis de citocinas prÃ-inflamatÃrias e sÃntese de Ãxido nÃtrico em modelo de inflamaÃÃo aguda. As quitinases do lÃtex de C. procera representam interessantes molÃculas para prospecÃÃo biotecnolÃgica em defesa vegetal e farmacologia.
Calotropis procera is a latificer plant in the Apocynaceae family. Defensive proteins with activity against phytophagous insects and phytopathogenic fungi in latex have been described. Latexâs proteic fraction also performs pharmacological activities, such as selective cytotoxic effect in carcinogenic cells. From the proteic fraction effective against neoplastic cells, this work had the goal to identify and further characterize cytotoxic protein(s) biochemically, biologically, and evaluate their biotechnological prospects. Soluble proteins in latex (LP) have been fractioned in ion-exchange matrix, and the fraction capable of cytotoxicity was further fractioned in another ion-exchange matrix (Mono-Q) coupled to a medium-pressure system. P4 was identified as cytotoxic fraction, showing an IC50 of 2.2, 1.2 and 2.9 mg/mL for the cell lines HCT-116, Ovcar-8 and SF-295, respectively. Proteomic analysis of the cytotoxic fraction by two-dimensional electrophoresis allowed 15 spots to be identified, comprising acid proteins (pI among 4 and 6) with 30 kDa apparent molecular weight. All spots were identified as chitinases when evaluated by mass spectrometry, and showed intact mass of 27.4 kDa. The sample reacted positively to the Schiff reagent, suggesting glycosilations. The carbohydrate content was estimated at 12.8%. The amino-terminal sequence obtained (1QPVMNLEYPRYLNDINDYRDDNNYD28) revealed 50% similarity with Solanum lycopersicum, Oryza sativa and Nicotiana tomentosiformes chitinases, among others. The enzymes showed strong chitinolytic activity, with optimal pH varying between 5-6 and optimal temperature of 25 ÂC. The chitinolytic activity was diminished when treated with increasing concentrations of DTT (3, 10 and 30 mM), which suggests the presence of disulfide bonds stabilizing the enzyme. Circular dichroism analyses indicate a larger presence of alpha helices in the structure and that the isoforms has low resistance to pH and temperature variation. High-resolution images generated through atomic force microscopy suggested sample homogeneity and a hexameric configuration. The chitinases did not inhibit mycelial growth of phytopathogenic fungi Fusarium oxysporum and Colletotrichum gloeosporioides, however reduced the germination C. gloeosporioides spores. In consonancy the chitinases did not induce spore oxidative stress, but caused a slight change in membrane permeability of the evaluated spores. Laticifer chitinases (0.1% w/w) showed a strong deleterious effect on the phytophagous insect Callosobruchus maculatus. Effects produced a 57% survival reduction, larval weight reduction (7.8 mg  0.2 / 4.0  0.8), adult insets emergence reduction (50%), in addition to prolonging the mean maturation time from 28 to 33 days. The chitinases (2 mg/Kg, i.v.) showed a strong anti-inflammatory activity, reducing 95% of neutrophil infiltration into the peritoneal cavity in mouse in an inflammation induced by carrageenan assay. L-NAME and Aminoguanidine, two inhibitors of nitric oxide synthase, reversed this effect, possibly indicating involvement of nitric oxide in the effects observed. This action was associated to a reduction of pro-inflammatory cytokines TNF-α and IL-1 levels within the peritoneal cavity and increased serum levels of pro-inflammatory cytokines TNF-α, IL-6 and IL-1. The conclusion is reached that many isoforms of chitinases coexist in C. procera latex. These proteins act possibly in defense against insects, though low action against fungi is shown. Laticifer chitinases were identified as latex proteins cytotoxic on neoplastic cells and they have even been able to modulate pro-inflammatory cytokines levels and nitric oxide in an acute inflammation model. C. procera laticifer chitinases represent interesting molecules for biotechnology prospection in plant defense and pharmacology.