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1
Richer-Leclerc, C., J. A. Rioux, S. Végiard, J. Côté, and L. Guillemette. "Évaluation de la tolérance de Betula pendula et de Betula nigra aux conditions climatiques du nord-est canadien." Canadian Journal of Plant Science 77, no. 3 (July 1, 1997): 445–51. http://dx.doi.org/10.4141/p96-032.
Анотація:
A 5-yr study was conducted to evaluate the winter hardiness and growth potential of seedlings of Betulapendula and Betulanigra in order to provide adequate recommendations regarding their adaptation to different climatic conditions. Plants were grown at nine sites of the Réseau d'Essais des Plantes Ligneuses Ornementales du Québec. Betulapendula and B. nigra were not severely affected by winter conditions at any sites and could be used in zones 2 and 2a, respectively. Although, B. pendula could be successfully grown in all tested area, B. nigra could be better produced in zone 5. Key words: Betulapendula, Betulanigra, birch, hardiness, winter damage, growth potential, evaluation
2
Heiss, Ernst, and Reinhard Remane. "Adaptation or Coevolution in Associations of Phytophagous Endemic Bugs and Vascular Plants on the Canary Islands (Heteroptera)." Entomologia Generalis 19, no. 1-2 (September 1, 1994): 65–78. http://dx.doi.org/10.1127/entom.gen/19/1994/065.
3
Cargnelutti, D., T. F. Marostica, G. S. Moura, V. C. Da Luz, E. A. C. M. Guimarães, and L. H. Cazarolli. "Does Allium sativum L. tolerate water deficit?" Scientific Electronic Archives 12, no. 6 (December 2, 2019): 43. http://dx.doi.org/10.36560/1262019963.
Анотація:
The objective of this work was to evaluate the effect on the physiological and biochemical aspects of garlic submitted to water deficit, knowing that the popular garlic Allium sativum L. is a culture known worldwide for its medicinal, culinary and ecological properties of agricultural pests. were constituted with water condition of 100; 75; 50 and 25% of pot capacity (CP). Three bulbs were planted per pot (5 L) containing Plantmax® substrate, irrigated every two days, according to pot capacity. The chlorophyll index was evaluated during the first and last week of greenhouse treatments. At 45 days after the treatments, the garlic plants were harvested to evaluate the physiological and biochemical parameters. Garlic plants showed to be sensitive to water deficit, resulting in lower leaf length and fresh biomass. Water stress induced the activity of the APX enzyme in the leaves and of the POD in the roots, as well as increase of proteins in the bulbilhos as biochemical mechanisms of adaptation.
4
Vincent, Bryan. "Contribution de la symbiose fixatrice d’azote dans l’adaptation d’une légumineuse à des sols contrastés : le modèle Acacia spirorbis et les contraintes édaphiques extrêmes rencontrées en Nouvelle-Calédonie." BOIS & FORETS DES TROPIQUES 341 (July 20, 2019): 87. http://dx.doi.org/10.19182/bft2019.341.a31757.
Анотація:
Acacia spirorbis est une légumineuse endémique de Nouvelle-Calédonie se développant sur des sols calcaires, métallifères et volcano-sédimentaires, établissant des symbioses avec des bactéries fixatrices d’azote. Pour comprendre la contribution de la symbiose dans l’adaptation de la plante à des milieux contrastés et parfois extrêmes, nous avons évalué la fixation d’azote en conditions naturelles, caractérisé les rhizobia associés à cette plante et analysé la réponse adaptative de la plante aux éléments traces métalliques dans ses tissus racinaires, notamment au niveau des nodules.Nous avons mis en évidence que la symbiose rhizobienne fournissait plus de 80 % de l’azote total chez des populations naturelles d’A. spirorbis se développant sur des sites d’étude présentant des sols calcaires, métallifères et volcano-sédimentaires. Cette valeur est remarquable puisque, pour A. mangium, A.melanoxylon et A.mucronata, les valeurs moyennes sont respectivement de 50 %, 43 % et 58 %. Les rhizobia symbiotiques associés à A. spirorbis appartiennent aux α- et β-protéobactéries, genres Bradyrhizobium et Paraburkholderia, révélant ainsi une très large gamme de symbiontes et une faible sélectivité de partenaire. De manière remarquable, la taxonomie et le phénotype de ces souches sont structurés et adaptés aux conditions édaphiques. Enfin, les signatures chimiques des tissus internes des nodules reflètent les propriétés chimiques des sols dans lesquels ils se sont développés, indiquant une potentielle gestion des éléments traces métalliques dans ces tissus. Tous ces éléments suggèrent que la symbiose fixatrice d’azote contribue de manière significative dans l’adaptation d’Acacia spirorbis à des sols contrastés et pouvant présenter une toxicité polymétallique extrême.
5
Yu, Haomiao, Yuan Yuan, Sijiao Wang, Guoming Wu, Haishen Xu, Jianglan Wei, Le Ju, Yulin Huang, and Hui Chen. "Interspecies Evolution and Networks Investigation of the Auxin Response Protein (AUX/IAA) Family Reveals the Adaptation Mechanisms of Halophytes Crops in Nitrogen Starvation Agroecological Environments." Agriculture 11, no. 8 (August 16, 2021): 780. http://dx.doi.org/10.3390/agriculture11080780.
Анотація:
The maintenance of adaptability to the exposure to agroecological extreme environments is generally a feature after the long-term domestication of crops. Auxin influences plant growth in all environments. At present, the research on the auxin response factors (ARFs) has been very in-depth. However, there is still a large gap in the research on the origin, evolution, and regulatory networks of the Auxin-responsive protein (AUX/IAA) family. Here, we identified 495 AUX/IAAs from 19 representative species covering aquatic algae to angiosperms and found that they originated from early bryophytes and mainly expanded by polyploidy in angiosperms. In the domesticated crop quinoa, the evolutionary model of the IAA family is relatively independent and forms a robust regulatory network with auxin signals and energy metabolism pathways. In the nitrogen-deficient environment, CqIAAs (Chenopodium quinoa AUX/IAAs), auxin signals, and TCA pathway genes induced expression in young roots to promote root elongation and could regulate the balance of carbon and nitrogen metabolism to maintain the adaptation of early seedlings in poor environments. Furthermore, a rapidly evolving CqIAA (AUR62011942) not only has different expression levels in two quinoa seeds but also has a significant stress response when seedlings face nitrogen deficiency stress, which may be a key factor in the adaptive regulation of the barren environment. Our research provides valuable clues for understanding the origin, evolution, and functional innovation of auxin signaling and also provides a reference for future agricultural breeding in the context of global environmental changes.
6
Dejean, A. "Adaptation d'Oecophylla longinoda [Formicidae-Formicinae] aux variations spatio-temporelles de la densité de proies." Entomophaga 36, no. 1 (March 1991): 29–54. http://dx.doi.org/10.1007/bf02374635.
7
Weaver, Ryan J. "Hypothesized Evolutionary Consequences of the Alternative Oxidase (AOX) in Animal Mitochondria." Integrative and Comparative Biology 59, no. 4 (April 27, 2019): 994–1004. http://dx.doi.org/10.1093/icb/icz015.
Анотація:
Abstract The environment in which eukaryotes first evolved was drastically different from what they experience today, and one of the key limiting factors was the availability of oxygen for mitochondrial respiration. During the transition to a fully oxygenated Earth, other compounds such as sulfide posed a considerable constraint on using mitochondrial aerobic respiration for energy production. The ancestors of animals, and those that first evolved from the simpler eukaryotes have mitochondrial respiratory components that are absent from later-evolving animals. Specifically, mitochondria of most basal metazoans have a sulfide-resistant alternative oxidase (AOX), which provides a secondary oxidative pathway to the classical cytochrome pathway. In this essay, I argue that because of its resistance to sulfide, AOX respiration was critical to the evolution of animals by enabling oxidative metabolism under otherwise inhibitory conditions. I hypothesize that AOX allowed for metabolic flexibility during the stochastic oxygen environment of early Earth which shaped the evolution of basal metazoans. I briefly describe the known functions of AOX, with a particular focus on the decreased production of reactive oxygen species (ROS) during stress conditions. Then, I propose three evolutionary consequences of AOX-mediated protection from ROS observed in basal metazoans: 1) adaptation to stressful environments, 2) the persistence of facultative sexual reproduction, and 3) decreased mitochondrial DNA mutation rates. Recognizing the diversity of mitochondrial respiratory systems present in animals may help resolve the mechanisms involved in major evolutionary processes such as adaptation and speciation.
8
Lin, Zesong, Jianyan Wu, Pierce A. Jamieson, and Chuanqing Zhang. "Alternative Oxidase Is Involved in the Pathogenicity, Development, and Oxygen Stress Response of Botrytis cinerea." Phytopathology® 109, no. 10 (October 2019): 1679–88. http://dx.doi.org/10.1094/phyto-01-19-0012-r.
Анотація:
Alternative oxidase (AOX) is a ubiquinol terminal oxidase that is involved in fungal mitochondrial oxidative phosphorylation. In this study, we analyzed the roles of AOX in Botrytis cinerea by generating BcAOX deletion mutants. The mutants exhibited defects in mycelial growth, sporulation, spore germination, and virulence. Furthermore, the sensitivity of the mutants to quinone outside inhibitor fungicides and oxidative stress were increased. All phenotypic variations could be restored in the complemented strain. In summary, these results showed that BcAOX is involved in the regulation for vegetative development, adaptation to environmental stress, and virulence of B. cinerea.
9
Medrano Macías, Julia, María Guadalupe López Caltzontzit, Erika Nohemi Rivas Martínez, Willian Alfredo Narváez Ortiz, Adalberto Benavides Mendoza, and Paulino Martínez Lagunes. "Enhancement to Salt Stress Tolerance in Strawberry Plants by Iodine Products Application." Agronomy 11, no. 3 (March 22, 2021): 602. http://dx.doi.org/10.3390/agronomy11030602.
Анотація:
Iodine is a non-essential element for land plants, but is considered as a beneficial element, related to antioxidant capacity, environmental adaptations and improvement of plant growth. Salinity is one of the more recurrent abiotic stresses worldwide, seriously affecting vegetal production. The aim of this work was to evaluate iodine application (Q products® and KIO3, Quimcasa de México, Naucalpan, Mexico) in strawberry plants under normal and salt stress conditions. Growth, antioxidant content, essential minerals, iodine accumulation and fruit quality were evaluated. The results showed that, under stress conditions, the application of Q products increased ascorbate peroxidase (APX) and catalase (CAT) activity as well as glutathione (GSH) content and yield in fruit, without avoiding biomass loss; with the application of KIO3 an increase in GSH and APX activity as well as P and K concentrations were obtained. In leaves an increase in P, Ca, Mn and iodine accumulation was evidenced with the application of Q products, and an increased concentration of ascorbic acid and iodine with KIO3 treatments. Under normal conditions in fruits, the application of Q products increased phenolic compounds synthesis; additionally, an increase in Ca and Mn concentrations was shown. KIO3 application increased the firmness and Mn. In leaves, the application of Q products increased chlorophyll a, b and calcium. In conclusion, the application of iodine improves the quality value of strawberries under normal conditions and provides an enhancement of salt stress tolerance.
10
Kashyap, Ruchika, Zsolt Csintalan, Katalin Veres, and Evelin Ramóna Péli. "Seasonal variation of antioxidant enzymatic responses in the desiccation-tolerant bryophyte Syntrichia ruralis (Hedw.) Web. & Mohr." Columella : Journal of Agricultural and Environmental Sciences 8, no. 1 (2021): 37–50. http://dx.doi.org/10.18380/szie.colum.2021.8.1.37.
Анотація:
Bryophytes are poikilohydric organisms that can be used as model plants to study desiccation tolerance mechanisms. The main objective of this study was to examine the activities of the antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT) and guaiacol peroxidase (POD) in the rehydrated and desiccated states in Syntrichia ruralis (Hedw.) Web. & Mohr. from two slopes, one North-east (NE) and one South-west (SW) facing and collected in different seasons. Our results showed seasonal variation in the enzymatic activities of APX, CAT and POD between the slopes in both the rehydrated and desiccated states. The mean value of all the activities of APX, CAT and POD and MDA contents (a measure of lipid peroxidation) tended to be higher in moss cushions collected from the NE compared to the SW facing slopes except in summer season. The mean values of all enzymatic activities were higher in desiccated states as compared with rehydrated states. Protein content has lower values in summer and winter season. Differences in the antioxidant activities of the mosses growing on the two slopes may reflect adaptations to desiccation stress.
11
Grillot, Myriam, Jonathan Vayssières, François Guerrin, and Philippe Lecomte. "Modélisation conceptuelle de la gestion adaptative de la biomasse face à l’aléa climatique en systèmes agro-sylvopastoraux." Cahiers Agricultures 27, no. 5 (September 2018): 55004. http://dx.doi.org/10.1051/cagri/2018034.
Анотація:
Le recyclage de la biomasse végétale et animale joue un rôle central dans le fonctionnement des systèmes agro-sylvopastoraux. En Afrique de l’Ouest, la variabilité des précipitations impacte les pratiques de gestion de cette biomasse pour nourrir les hommes, le bétail, le sol et les plantes. Cette étude décrit un modèle d’action conceptuel basé sur des règles ≪ si-alors-sinon » qui représentent les décisions de gestion de la biomasse des ménages agricoles. L’étude souligne les conséquences en cascade d’un aléa pluviométrique sur le calendrier des activités agricoles, les quantités et la nature des biomasses mobilisées. Les activités les plus directement impactées sont le semis et la récolte des cultures, l’alimentation animale et, indirectement, la fertilisation des sols et la gestion des stocks alimentaires. Le modèle d’action regroupe les principales règles et modalités de gestion constituant les pratiques des ménages agricoles. Il est défini pour quatre types de ménages agriculture-élevage selon leurs activités dominantes : agricultureversusélevage et vivrierversusvente. Les ménages vivriers et élevage sont plus sensibles aux variations pluviométriques. Ils présentent une gestion plus adaptative car ils sont davantage dépendants de leur propre production. Ce modèle d’action a été conçu en vue de son intégration dans un modèle à base d’agents pour simuler les conséquences de l’aléa pluviométrique sur les flux de biomasses résultant des interactions entre les ménages agricoles d’une communauté villageoise en Afrique de l’Ouest.
12
Rabhi, Khellaf, Amel Akli, Ahlem Djouhri, Nassima Yahi, Salem Boudedja, and Mahand Messaoudene. "Bilan et croissance des reboisements de cèdre de l’Atlas, Cedrus atlantica (Endl.) Carrière, en Algérie : cas du Djurdjura et de l’Atlas blidéen." BOIS & FORETS DES TROPIQUES 337 (November 26, 2018): 3. http://dx.doi.org/10.19182/bft2018.337.a31627.
Анотація:
L’étude a été menée sur trois plantations de cèdre de l’Atlas réalisées au Djurdjura, et quatre autres dans l’Atlas blidéen, en Algérie. Celles-ci se caractérisent par un contraste écologique et par des différences liées aux méthodes de préparation et de mise en place de chaque plantation. L’objectif était de comparer, en mettant en évidence l’influence de ces conditions, la croissance en hauteur, en diamètre et radiale de ces plantations, avec quelques cédraies naturelles et artificielles d’Algérie, du Maroc et de France. L’analyse descriptive des paramètres dendrométriques a confirmé les potentialités productives du cèdre de l’Atlas et sa faculté à coloniser les zones de montagne. Cette constatation découle du taux de réussite exceptionnel déduit des inventaires. En effet, quelle que soit la plantation, le taux de réussite dépasse 80 %. L’accroissement radial annuel atteint 5,6 mm. À 34 ans, le diamètre moyen avoisine 40 cm et la hauteur dominante 16 m. Bien que les parties préservées des plantations soient une réussite, les volumes initialement reboisés sont réduits de moitié en raison du pacage. Les résultats montrent l’effet positif des cépées de chêne vert sur la reprise et la croissance des jeunes plants, ainsi que l’importance des travaux préparatifs visant à stabiliser les terrains en forte pente et à améliorer le comportement hydrique du sol (banquettes et terrasses). Bien que le cèdre croisse de manière satisfaisante en zones sèches, il apparaît plus productif en dehors de son aire de répartition naturelle, par exemple en Bretagne. Cette essence pourrait constituer une espèce d’avenir pour les reboisements et l’amélioration des peuplements en Algérie, en raison de son adaptation aux conditions de milieu difficiles (sécheresse) et de sa productivité.
13
Maslennikova, Dilara, and Oksana Lastochkina. "Contribution of Ascorbate and Glutathione in Endobacteria Bacillus subtilis-Mediated Drought Tolerance in Two Triticum aestivum L. Genotypes Contrasting in Drought Sensitivity." Plants 10, no. 12 (November 23, 2021): 2557. http://dx.doi.org/10.3390/plants10122557.
Анотація:
We evaluated the effect of endobacteria Bacillus subtilis (strain 10–4) as a co-inoculant for promoting plant growth and redox metabolism in two contrasting genotypes of Triticum aestivum L. (wheat): Ekada70 (drought tolerant (DT)) and Salavat Yulaev (drought susceptible (DS)) in early stages of adaptation to drought (12% PEG–6000). Results revealed that drought reduced growth and dramatically augmented oxidative stress markers, i.e., hydrogen peroxide (H2O2) and lipid peroxidation (MDA). Furthermore, the depletion of ascorbate (AsA) and glutathione (GSH), accompanied by a significant activation of ascorbate peroxidase (APX) and glutathione reductase (GR), in both stressed wheat cultivars (which was more pronounced in DS genotype) was found. B. subtilis had a protective effect on growth and antioxidant status, wherein the stabilization of AsA and GSH levels was revealed. This was accompanied by a decrease of drought-caused APX and GR activation in DS plants, while in DT plants additional antioxidant accumulation and GR activation were observed. H2O2 and MDA were considerably reduced in both drought-stressed wheat genotypes because of the application of B. subtilis. Thus, the findings suggest the key roles in B. subtilis-mediated drought tolerance in DS cv. Salavat Yulaev and DT cv. Ekada70 played are AsA and GSH, respectively; which, in both cases, resulted in reduced cell oxidative damage and improved growth in seedlings under drought.
14
Barbaro, Luc, Emmanuel Corcket, Thierry Dutoit, and Jean-Paul Peltier. "Réponses fonctionnelles des communautés de pelouses calcicoles aux facteurs agro-écologiques dans les Préalpes françaises." Canadian Journal of Botany 78, no. 8 (August 1, 2000): 1010–20. http://dx.doi.org/10.1139/b00-071.
Анотація:
The identification of functional groups in calcareous grasslands of southern Vercors (Rhône-Alpes, France) is investigated through relationships between biological traits of the species and agro-ecological factors. Community patterns are determined by (i) the level of edaphic stress (oligotrophy and xericity) and (ii) the regime and the intensity of agropastoral management (grazing and mechanical cutting). In such grasslands submitted to regular disturbance, life traits related to dispersal and regeneration processes have greater importance for the differentiation of species than morphological traits, and Grime's adaptative strategies are the best predictors of species ordination on agro-ecological gradients (e.g., stress and disturbance). A classification of species in functional groups based on the same life traits and similar responses to disturbances is proposed, and its role in defining adequate conservation management of calcareous grassland by low-intensity livestock farming is discussed. The functional role of grazing is emphasized by the relationship between species dominance or rarity and their levels of consumption and dispersion by sheeps. In calcareous grassland communities, dominant species are the most palatable and the most dispersed by sheeps, while rarer species depend on other dispersal modes, such as seed rain or mowing machinery.Key words: life traits, functional groups, agropastoral practices, conservation management, RLQ analysis.
15
Bariteau, M., and J. Pommery. "Variabilité géographique et adaptation aux contraintes du milieu méditerranéen des pins de la section halepensis : résultats (provisoires) d'un essai en plantations comparatives en France." Annales des Sciences Forestières 49, no. 3 (1992): 261–76. http://dx.doi.org/10.1051/forest:19920305.
16
Cheng, Jian, Chun-Xia He, Zhong-Wei Zhang, Fei Xu, Da-Wei Zhang, Xiao Wang, Shu Yuan, and Hong-Hui Lin. "Plastid Signals Confer Arabidopsis Tolerance to Water Stress." Zeitschrift für Naturforschung C 66, no. 1-2 (February 1, 2011): 47–54. http://dx.doi.org/10.1515/znc-2011-1-207.
Анотація:
Plastid-to-nucleus retrograde signalling coordinates nuclear gene expression with chloroplast function and is essential for the photoautotrophic life-style of plants. The relationship between plastid signalling and water stress response was investigated with genome uncoupled (gun) mutants, gun1, gun3, and gun5, and an abscisic acid (ABA)-responsible transcription factor mutant, abi4. The results showed that gun1, gun3, gun5, and abi4 mutants suffered from more oxidative damages than the wild-type plants under the water stress and the water stress + herbicide (norflurazon, NF) co-treatment. Superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) activities could not be prompted in the plastidsignalling defective mutants under the stress conditions. At the same time, Lhcb expression was not repressed in the plastid-signalling defective mutants by the NF treatment or water stress. Therefore, the photosynthetic apparatus in the mutant cells could not be closed during the stresses and the excessive light caused more photodamages on the mutant leaves. The roles of GUN1, GUN3, GUN5 and ABI4 proteins in environmental stress adaptation have been discussed.
17
Rakotovololonalimanana, Herizo, Hery Rakotondraoelina, Gilles Chaix, Lolona Ramamonjisoa, Marie-France Thévenon, Honoré Randrianjafy, and Tahiana Ramananantoandro. "Adaptation et variabilité génétique de la croissance de Liquidambar styraciflua L. de l'essai de provenances à Mandraka, Madagascar." BOIS & FORETS DES TROPIQUES 320, no. 320 (March 17, 2014): 31. http://dx.doi.org/10.19182/bft2014.320.a20542.
Анотація:
Liquidambar styraciflua ou copalme d'Amérique est une espèce feuillue originaire du Sud-Est des États Unis d'Amérique et de l'Amérique Centrale. L'espèce possède un comportement remarquable en plantation et les propriétés de son bois en font un matériau à usage multiples. En 1986, dans le cadre d'un essai international de provenances de Liquidambar styraciflua, le Commonwealth Forestry Institute (CFI) d'Oxford a diffusé dans plusieurs pays (Brésil, Mexique, Madagascar) des graines de treize provenances récoltées essentiellement dans l'aire de distribution naturelle de l'espèce dans l'Est des États-Unis d'Amérique, du Mexique et de l'Amérique centrale. À Madagascar, le Département des Recherches Forestières et Piscicoles (DRFP-FOFIFA) les a plantées à Mandraka (Madagascar). Des données annuelles de la croissance ont été collectées durant 25 ans ; cependant les résultats n'ont pas encore été publiés contrairement à ceux du Brésil et du Mexique. Il s'agit ici d'évaluer l'adaptation de l'essence à Mandraka et d'étudier la variabilité intraspécifique de sa croissance. Jusqu'à 25 ans, la croissance de l'espèce est régulière pour atteindre en moyenne 26 m en hauteur, 38 cm en diamètre et 0,12 m²/arbre en surface terrière. Les valeurs moyennes des provenances pour ces mêmes caractéristiques et la surface terrière sont significativement différentes. L'héritabilité au sens large à 25 ans est de 0,76, 0,60 et 0,63 respectivement pour la hauteur, le diamètre et la surface terrière, montrant un contrôle génétique de la croissance. Dans des conditions écologiques similaires et à âges équivalents, la croissance de L. styraciflua est équivalente à celle des espèces du genre Eucalyptus et supérieure à celle des Pinus. Par rapport aux essais internationaux du CFI, l'essai de provenances de L. styraciflua dans le site de la Mandraka montre une meilleure adaptation et une bonne croissance de l'espèce. (Résumé d'auteur)
18
Shahidi, Reihaneh, Junko Yoshida, Mathias Cougnon, Dirk Reheul, and Marie-Christine Van Labeke. "Morpho-physiological responses to dehydration stress of perennial ryegrass and tall fescue genotypes." Functional Plant Biology 44, no. 6 (2017): 612. http://dx.doi.org/10.1071/fp16365.
Анотація:
Worldwide drought stress is the most important restriction factor on food and fodder productivity. In this study, morpho-physiological adaptations to dehydration stress were investigated in two tall fescue (Festuca arundinacea Schreb.) genotypes (Fa13 and Fa19 with a high and low sheep grazing preference respectively) and Lolium perenne L. Drought stress as evaluated by decreasing stomatal conductance and chlorophyll content, chlorophyll fluorescence parameters and fructan concentration were first observed in L. perenne (16 days after the start of the drought stress). Furthermore, after 20 days of drought stress the activities of ascorbate peroxide (APX), catalase (CAT), and superoxide dismutase (SOD) were reduced in stressed plants indicating that the capacity to scavenge ROS diminished under severe stress though no differences between genotypes were observed. Osmotic adjustment by carbohydrates did also not differ between the genotypes. Proline, however, reached its highest level in drought-stressed L. perenne followed by Fa13 and Fa19 respectively. The studied species showed a similar degree in response in the traits assessed when plants were exposed to dehydration stress; however changes were first observed in L. perenne.
19
Liu, Nanqing, Shaoyan Lin, and Bingru Huang. "Differential Effects of Glycine Betaine and Spermidine on Osmotic Adjustment and Antioxidant Defense Contributing to Improved Drought Tolerance in Creeping Bentgrass." Journal of the American Society for Horticultural Science 142, no. 1 (January 2017): 20–26. http://dx.doi.org/10.21273/jashs03962-16.
Анотація:
Glycine betaine (GB) and spermidine (Spd) are known to play roles in plant adaptation to stresses that induce dehydration, including drought stress. The objectives of this study were to examine whether improved drought tolerance by exogenous application of GB or Spd is associated with the increases in the endogenous accumulation of those solutes under drought stress in cool-season turfgrass species, and to determine the relative effects of those solutes on osmotic adjustment (OA) and antioxidant metabolism for improving drought tolerance. Creeping bentgrass (Agrostis stolonifera cv. Penncross) plants were treated with 200 mm GB or 0.1 mm Spd for 3 weeks by weekly foliar application before the exposure to drought stress; those plants were subsequently subjected to drought stress by withholding irrigation. The endogenous content of GB and Spd increased significantly through the exogenous application of either compound, to a greater magnitude for GB. The comparison of GB- or Spd-treated plants to untreated plants exposed to drought stress for growth [turf quality (TQ)] and physiological responses (water relations, membrane stability, and antioxidant metabolism) demonstrated that both compounds led to significant improvement in drought tolerance in creeping bentgrass. The improved drought tolerance by exogenous GB could be due to its contribution to OA by significant accumulation of endogenous GB, and activation of antioxidant enzymes with the greatest effects on ascorbate peroxidase (APX). Exogenous Spd did not cause increases in leaf OA despite of the increased endogenous accumulation, but significantly enhanced antioxidant enzyme activities, with the most pronounced effects on catalase (CAT). This study demonstrated that GB and Spd had different effects on OA and activated different antioxidant defense pathways, protecting plants from drought damages in creeping bentgrass.
20
Wang, Guowei, Xiaowei Wang, Hongping Ma, Haili Fan, Fan Lin, Jianhui Chen, Tuanyao Chai, and Hong Wang. "PcWRKY11, an II-d WRKY Transcription Factor from Polygonum cuspidatum, Enhances Salt Tolerance in Transgenic Arabidopsis thaliana." International Journal of Molecular Sciences 23, no. 8 (April 14, 2022): 4357. http://dx.doi.org/10.3390/ijms23084357.
Анотація:
Being an invasive plant, Polygonum cuspidatum is highly resilient and can survive in unfavorable environments for long periods; however, its molecular mechanisms associated with such environmental resistance are largely unknown. In this study, a WRKY transcription factor (TF) gene, PcWRKY11, was identified from P. cuspidatum by analyzing methyl jasmonate (MeJA)-treated transcriptome data. It showed a high degree of homology with WRKY11 from Arabidopsis thaliana, containing a WRKY domain and a zinc finger structure and II-d WRKY characteristic domains of HARF, a calmodulin-binding domain (C-motif), and a putative nuclear localization signal (NLS) through sequence alignment and functional element mining. qPCR analysis showed that the expression of PcWRKY11 can be induced by NaCl, osmotic stress, and UV-C. In this study, we also found that overexpression of PcWRKY11 in A. thaliana could significantly increase salt tolerance. To explore its possible molecular mechanism, further investigations showed that compared with the wild type (WT), under salt stress, the transgenic plants showed a lower malondialdehyde (MDA) content, higher expression of ascorbate peroxidase (APX) and superoxide dismutase (SOD), and higher enzyme activity of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT). Moreover, the transgenic plants also showed higher expression of Δ1-pyrroline-5-carboxylate synthase (AtP5CS), and higher contents of proline and soluble sugar. Taken together, these results indicate that PcWRKY11 may have a positive role in plants’ adaptation to salinity conditions by reducing reactive oxygen species (ROS) levels and increasing osmosis substance synthesis.
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Arzola Flores, Jesús Andrés, Patricia Tello Cano, Abraham Maldonado García, and Gabriel Guarneros Bejarano. "Las organizaciones como Sistemas Complejos." Acta Universitaria 29 (October 9, 2019): 1–15. http://dx.doi.org/10.15174/au.2019.2111.
Анотація:
Las organizaciones o empresas son sistemas que poseen la habilidad de auto-organizarse, adaptarse y evolucionar, son sistemas alejados del equilibrio debido a que son entes abiertos; es decir, existe un constante flujo de información desde y hacia ellas; por lo tanto, es posible estudiar a las organizaciones como sistemas complejos. Actualmente, el constante flujo de información desde y hacia las empresas se da principalmente por medios digitales o Social Media; por ello, las organizaciones requieren de una figura profesional que cuente con las habilidades, destrezas y herramientas que le permitan gestionar dicha información. Sin embargo, en la actualidad no existe un perfil académico que posea las herramientas para la gestión del constante flujo de información y, mucho menos, que logre traducir información basada en datos en decisiones y acciones. En el presente artículo se plantea la hipótesis de la organización como un sistema complejo, se construye una estructura organizacional adaptativa y, finalmente, se describe la necesidad de crear un perfil profesional que posea las herramientas que le permitan gestionar el constante flujo de información proveniente de Social Media, para mantener a las organizaciones en un estado transitorio entre la estabilidad y la inestabilidad, es decir, al borde del caos.
22
Jiang, Dan, Bin Lu, Liantao Liu, Wenjing Duan, Li Chen, Jin Li, Ke Zhang, et al. "Exogenous melatonin improves salt stress adaptation of cotton seedlings by regulating active oxygen metabolism." PeerJ 8 (December 11, 2020): e10486. http://dx.doi.org/10.7717/peerj.10486.
Анотація:
Melatonin is a small-molecule indole hormone that plays an important role in participating in biotic and abiotic stress resistance. Melatonin has been confirmed to promote the normal development of plants under adversity stress by mediating physiological regulation mechanisms. However, the mechanisms by which exogenous melatonin mediates salt tolerance via regulation of antioxidant activity and osmosis in cotton seedlings remain largely unknown. In this study, the regulatory effects of melatonin on reactive oxygen species (ROS), the antioxidant system, and osmotic modulators of cotton seedlings were determined under 0–500 µM melatonin treatments with salt stress induced by 150 mM NaCl treatment. Cotton seedlings under salt stress exhibited an inhibition of growth, excessive hydrogen peroxide (H2O2), superoxide anion (O2−), and malondialdehyde (MDA) accumulations in leaves, increased activity levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and elevated ascorbic acid (AsA) and glutathione (GSH) content in leaves. However, the content of osmotic regulators (i.e., soluble sugars and proteins) in leaves was reduced under salt stress. This indicates high levels of ROS were produced, and the cell membrane was damaged. Additionally, osmotic regulatory substance content was reduced, resulting in osmotic stress, which seriously affected cotton seedling growth under salt stress. However, exogenous melatonin at different concentrations reduced the contents of H2O2, O2−, and MDA in cotton leaves, increased the activity of antioxidant enzymes and the content of reductive substances (i.e., AsA and GSH), and promoted the accumulation of osmotic regulatory substances in leaves under salt stress. These results suggest that melatonin can inhibit ROS production in cotton seedlings, improve the activity of the antioxidant enzyme system, raise the content of osmotic regulation substances, reduce the level of membrane lipid peroxidation, and protect the integrity of the lipid membrane under salt stress, which reduces damage caused by salt stress to seedlings and effectively enhances inhibition of salt stress on cotton seedling growth. These results indicate that 200 µM melatonin treatment has the best effect on the growth and salt tolerance of cotton seedlings.
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Zhao, Yuncheng, Mingyue Zhao, Lei Zhang, Chunyi Wang, and Yinlong Xu. "Predicting Possible Distribution of Tea (Camellia sinensis L.) under Climate Change Scenarios Using MaxEnt Model in China." Agriculture 11, no. 11 (November 10, 2021): 1122. http://dx.doi.org/10.3390/agriculture11111122.
Анотація:
Climate change has dramatic impacts on the growth and the geographical distribution of tea (Camellia sinensis L.). Assessing the potential distribution of tea will help decision makers to formulate appropriate adaptation measures to use the altered climatic resources and avoid the damage from climate hazards. The objective in this study is to model the current and future distribution of tea species based on the four SSPs scenarios using the MaxEnt model in China. For the modeling procedure, tea growth records in 410 sites and 9 climate variables were used in this paper. The area under the receiver operating characteristic (ROC) curve (AUC) was used to evaluate the performance of the model. The AUC value was over 0.9 in this study, showing the excellent simulation result of the model. In relation to the current distribution, areas of 82.01 × 104 km2 (8.51% of total land area in China), 115.97 × 104 km2 (12.03% of total land area in China), and 67.14 × 104 km2 (6.97% of total land area in China) were recognized as Marginal, Medium, and Optimal climate suitable habitats for tea over China. Compared to the current distribution, most of the Optimal suitability areas in southeast China would be lost in four scenarios. The area of Marginal and Medium suitable habitats would expand in SSP370 and SSP585, especially in 2041–2061 and 2081–2100. The suitable area of tea would expand northwards and westwards, suggesting that additional new suitable habitats could be created for tea production with the future climate change, especially in Shandong, Henan, Guizhou, and Yunnan Provinces. This research would provide vital scientific understanding for policy making on tea production, tea garden site chosen and adopyion of adaptation methods in the future.
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Głowacka, Katarzyna, Anna Źróbek-Sokolnik, Adam Okorski, and Janusz Najdzion. "The Effect of Cadmium on the Activity of Stress-Related Enzymes and the Ultrastructure of Pea Roots." Plants 8, no. 10 (October 14, 2019): 413. http://dx.doi.org/10.3390/plants8100413.
Анотація:
The analysis of the effects of cadmium (Cd) on plant cells is crucial to understand defense mechanisms and adaptation strategies of plants against Cd toxicity. In this study, we examined stress-related enzyme activities after one and seven days of Cd application and the ultrastructure of roots of Pisum sativum L. after seven days of Cd treatment (10, 50, 100, and 200 μM CdSO4). Our results showed that phenylalanine ammonia-lyase (PAL) activity and the amount of Cd accumulated in the roots were significantly positively correlated with the Cd concentration used in our experiment. However, Cd caused a decrease of all studied antioxidative enzyme activities (i.e., catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX)). The analysis of the ultrastructure (TEM) showed various responses to Cd, depending on Cd concentrations. In general, lower Cd concentrations (50 and 100 μM CdSO4) mostly resulted in increased amounts of oil bodies, plastolysomes and the accumulation of starch granules in plastids. Meanwhile, roots treated with a higher concentration of Cd (200 μM CdSO4) additionally triggered protective responses such as an increased deposition of suberin lamellae in the endodermal cell walls. This indicates that Cd induces a complex defense response in root tissues.
25
Bai, Juan, Tai Kang, Hongdou Wu, Baiyan Lu, Xiaogang Long, Xinjuan Luo, Yanyu Zhang, Yulu Zhou, and Chunmei Gong. "Relative contribution of photorespiration and antioxidative mechanisms in Caragana korshinskii under drought conditions across the Loess Plateau." Functional Plant Biology 44, no. 11 (2017): 1111. http://dx.doi.org/10.1071/fp17060.
Анотація:
The drought-tolerant plant Caragana korshinskii Kom. was used to investigate the relative contribution of photorespiration and antioxidative mechanisms to water-stress adaptations across the Loess Plateau. The samples were collected from Shenmu, Yulin and Dongsheng along with the reduction of rainfall. The results showed the lower leaf water potential and the lower content of O2•– and malondialdehyde (MDA) were found in the plants in drier zone. H2O2 didn’t show a significant difference among these sampling sites. Both photorespiratory rate (PR) and net photosynthetic rate (PN) increased with the decrease of rainfall. Low rainfall upregulated the gene expression and activities of photorespiratory enzymes. In addition, ascorbate peroxidase (APX), glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity and reduced glutathione (GSH), ascorbic acid (AsA) contents increased with the decrease of rainfall, whereas catalase (CAT) activity decreased. These results indicate photorespiration could play a protective role for the photosynthetic apparatus from photoinhibition and photodamage under low rainfall levels, which could also act together with the antioxidation system to improve the tolerance to drought in C. korshinskii.
26
Liu, Chenlin, and Xiuliang Wang. "Superoxide dismutase and ascorbate peroxidase genes in Antarctic endemic brown alga Ascoseira mirabilis (Ascoseirales, Phaeophyceae): data mining of a de novo transcriptome." Botanica Marina 63, no. 6 (December 16, 2020): 541–49. http://dx.doi.org/10.1515/bot-2020-0025.
Анотація:
AbstractThe Antarctic endemic brown alga Ascoseira mirabilis is physically and physiologically well adapted to the extreme polar environment. To better understand the molecular strategies associated with stress adaptation, the transcriptome of A. mirabilis was sequenced, and its antioxidant enzyme genes were identified and compared with other algae. A total of 126,576 unigenes with a mean length of 734 bp and N50 of 1174 bp was assembled from the transcriptome data. Phylogenetic analysis revealed that dramatic evolutionary changes had occurred in the brown algal superoxide dismutases (SODs) and class I peroxidases that were not consistent with the phylogeny of the species. Fe/Mn SODs are more prevalent in brown algae than in red and green algae. Two additional Fe-SODs in A. mirabilis were phylogenetically closely related to those of green algae, but not to those in other brown algae. We also identified three A. mirabilis ascorbate peroxidase (APx) genes that had a different origin from other brown algal APxs. The SOD and APx genes specifically identified in A. mirabilis will be crucial for understanding the evolution of the algal antioxidant enzymes that contribute to ecological success under extreme environmental conditions in the Antarctic region.
27
Galicia-Campos, Estrella, Beatriz Ramos-Solano, Mª Belén Montero-Palmero, F. Javier Gutierrez-Mañero, and Ana García-Villaraco. "Management of Plant Physiology with Beneficial Bacteria to Improve Leaf Bioactive Profiles and Plant Adaptation under Saline Stress in Olea europea L." Foods 9, no. 1 (January 7, 2020): 57. http://dx.doi.org/10.3390/foods9010057.
Анотація:
Global climate change has increased warming with a concomitant decrease in water availability and increased soil salinity, factors that compromise agronomic production. On the other hand, new agronomic developments using irrigation systems demand increasing amounts of water to achieve an increase in yields. Therefore, new challenges appear to improve plant fitness and yield, while limiting water supply for specific crops, particularly, olive trees. Plants have developed several innate mechanisms to overcome water shortage and the use of beneficial microorganisms to ameliorate symptoms appears as a challenging alternative. Our aim is to improve plant fitness with beneficial bacterial strains capable of triggering plant metabolism that targets several mechanisms simultaneously. Our secondary aim is to improve the content of molecules with bioactive effects to valorize pruning residues. To analyze bacterial effects on olive plantlets that are grown in saline soil, photosynthesis, photosynthetic pigments, osmolytes (proline and soluble sugars), and reactive oxygen species (ROS)-scavenging enzymes (superoxide dismutase-SOD and ascorbate peroxidase-APX) and molecules (phenols, flavonols, and oleuropein) were determined. We found photosynthetic pigments, antioxidant molecules, net photosynthesis, and water use efficiency to be the most affected parameters. Most strains decreased pigments and increased osmolytes and phenols, and only one strain increased the antihypertensive molecule oleuropein. All strains increased net photosynthesis, but only three increased water use efficiency. In conclusion, among the ten strains, three improved water use efficiency and one increased values of pruning residues.
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Stepanov, A. V., S. A. Kashin, N. S. Zabanova, O. A. Fedotova, A. V. Fedyaeva, I. V. Lyubushkina, T. P. Pobezhimova, and O. I. Grabelnych. "Characterization of Suspension Cultures of Arabidopsis thaliana (L.) Heynh Cells with Altered Expression of the Gene of Alternative Mitochondrial Oxidase Aox1a and Analysis of their Frost Resistance." Bulletin of Irkutsk State University. Series Biology. Ecology 35 (2021): 3–18. http://dx.doi.org/10.26516/2073-3372.2021.35.3.
Анотація:
The enzyme alternative cyanide-resistant oxidase (AOX) localized in mitochondria is involved in the processes of plant adaptation to various unfavorable biotic and abiotic factors. Transfer of electrons from ubiquinone to oxygen by alternative oxidase has a nonprotonmotive character and, by bypassing two sites of H+ pumping in complexes III and IV, lowers the energy efficiency of respiration and energy of electron flow through AOX is released as heat. In this work, we characterized heterotrophic suspension cultures of Arabidopsis thaliana (L.) Heynh cells obtained from seeds of plants with altered (reduced (AS-12 line) and increased (XX-2 line)) expression of the alternative oxidase gene AOX1a and studied their viability under subzero temperature (-10 °С for 3, 6, 9 hours). Cell viability and reactive oxygen species (ROS) production were assessed using fluorescence microscopy with fluorescein diacetate (FDA) and propidium iodide (PI) for cell viability measurement and H2DCF-DA for ROS measurement. The proportion of living cells was calculated as the proportion of FDApositive and PI-negative cells. Differences between the studied lines were determined in the content of mitochondrial proteins of the respiratory chain (AOX, COXII, NDB) and uncoupling protein (UCP), as well as in the intensity of formation of ROS and frost resistance. The obtained results confirmed the higher content of the AOX protein and its high contribution to mitochondrial respiration in line XX-2. Suspension culture cells of the AS-12 line showed a decrease in the AOX protein content and its contribution to mitochondrial respiration, compared to the wild type (Col-0) and line XX-2. Simultaneously with a decrease in the AOX protein content in the AS-12 cell culture, an increase in the content of the uncoupling protein UCP and subunit II of cytochrome oxidase (COXII) was observed. ROS generation was reduced in cell cultures of both XX-2 and AS-12. The obtained results indicate that the cells of the wildtype (Col-0) suspension culture were subjected to the most significant effect of subzero temperature. Long-term exposure (for 9 h) under -10 °С revealed significant differences in the viability of wild-type culture cells and lines with altered AOX1a gene expression. Cells of line XX-2 with an increased content of AOX turned out to be more resistant to subzero temperature compared to wild-type and AS-12 cells. However, while the proportion of living cells in the culture of the AS-12 line 48 h after exposure remained at the same level as immediately after it, in the suspension culture of the wild type cell death developed over time. The obtained results indicate the importance of alternative oxidase in the development of frost resistance in plant cell.
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Punia, Himani, Jayanti Tokas, Anurag Malik, Sonali Sangwan, Anju Rani, Shikha Yashveer, Saleh Alansi, Maha J. Hashim, and Mohamed A. El-Sheikh. "Genome-Wide Transcriptome Profiling, Characterization, and Functional Identification of NAC Transcription Factors in Sorghum under Salt Stress." Antioxidants 10, no. 10 (October 13, 2021): 1605. http://dx.doi.org/10.3390/antiox10101605.
Анотація:
Salinity stress has become a significant concern to global food security. Revealing the mechanisms that enable plants to survive under salinity has immense significance. Sorghum has increasingly attracted researchers interested in understanding the survival and adaptation strategies to high salinity. However, systematic analysis of the DEGs (differentially expressed genes) and their relative expression has not been reported in sorghum under salt stress. The de novo transcriptomic analysis of sorghum under different salinity levels from 60 to 120 mM NaCl was generated using Illumina HiSeq. Approximately 323.49 million high-quality reads, with an average contig length of 1145 bp, were assembled de novo. On average, 62% of unigenes were functionally annotated to known proteins. These DEGs were mainly involved in several important metabolic processes, such as carbohydrate and lipid metabolism, cell wall biogenesis, photosynthesis, and hormone signaling. SSG 59-3 alleviated the adverse effects of salinity by suppressing oxidative stress (H2O2) and stimulating enzymatic and non-enzymatic antioxidant activities (SOD, APX, CAT, APX, POX, GR, GSH, ASC, proline, and GB), as well as protecting cell membrane integrity (MDA and electrolyte leakage). Significant up-regulation of transcripts encoding the NAC, MYB, and WRYK families, NHX transporters, the aquaporin protein family, photosynthetic genes, antioxidants, and compatible osmolyte proteins were observed. The tolerant line (SSG 59-3) engaged highly efficient machinery in response to elevated salinity, especially during the transport and influx of K+ ions, signal transduction, and osmotic homeostasis. Our data provide insights into the evolution of the NAC TFs gene family and further support the hypothesis that these genes are essential for plant responses to salinity. The findings may provide a molecular foundation for further exploring the potential functions of NAC TFs in developing salt-resistant sorghum lines.
30
DIALLO, Fatimata Anna, Abdoulazize SANDWIDI, Madjelia Ebou Cangré DAO, Pauline BATIONO-KANDO, and Boukary Ousmane DIALLO. "Caractérisation phénotypique des plantules de quatre populations de Sclerocarya birrea (A. Rich.) Hochst. au Burkina Faso." BOIS & FORETS DES TROPIQUES 344 (July 21, 2020): 33–46. http://dx.doi.org/10.19182/bft2020.344.a31898.
Анотація:
Sclerocarya birrea (A. Rich.) Hochst. est un fruitier oléagineux d’Afrique. Les fortes mortalités après plantation sont dues à l’affectation inappropriée des plants dans les zones écologiques. La caractérisation phénotypique des plantules a pour objectif de déterminer dès le jeune âge des caractères d’adaptation aux conditions écologiques. L’étude porte sur 494 plantules originaires des populations de You, Yarci, Gonsé et Diapangou-Peulh au Burkina Faso. Celles-ci appartiennent à quatre localités circonscrites dans trois zones climatiques. Les résultats montrent que la levée groupée assure la présence de générations chevauchantes à l’intérieur des populations. L’analyse de variance qui fait apparaître des différences intra- et inter-population sur la majorité des variables traduit la diversité phénotypique des plantules. L’analyse en composantes principales montre des caractéristiques spécifiques à chaque population. Le dendrogramme de la classification ascendante hiérarchisée permet d’identifier trois groupes : G1 : Gonsé (55,88 %), Yarci (23,52 %) et You (20,58 %) ; G2 : You (46,15 %), Yarci (42,30 %), Diapangou-Peulh (7,69 %) et Gonsé (3,84 %) ; G3 : Diapangou-Peulh (90 %), Yarci (5 %) et You (5 %). Ces trois groupes traduisent le rapprochement phénotypique entre individus. Ces résultats mettent en évidence l’existence des gains génétiques pour la sélection individuelle et populationnelle. Ils montrent également que ces populations ne sont pas menacées d’impasse évolutive à court terme. L’étude des héritabilités indique que les caractères les plus héritables sont la hauteur de la tige (28,31 %), la longueur de la racine principale (44,30 %), le nombre de racines secondaires (81,89 %), le poids frais des racines (73,47 %) et le poids sec des racines (28,86 %). L’architecture du système racinaire traduit la capacité d’adaptation de Sclerocarya birrea à différents types de sols. Compte tenu de ces résultats, la sélection sur les caractères adaptatifs au jeune âge peut être envisagée.
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Kumar, Sunjeet, Gaojie Li, Jingjing Yang, Xinfang Huang, Qun Ji, Kai Zhou, Suliman Khan, Weidong Ke, and Hongwei Hou. "Investigation of an Antioxidative System for Salinity Tolerance in Oenanthe javanica." Antioxidants 9, no. 10 (October 1, 2020): 940. http://dx.doi.org/10.3390/antiox9100940.
Анотація:
Abiotic stress, such as drought and salinity, severely affect the growth and yield of many plants. Oenanthe javanica (commonly known as water dropwort) is an important vegetable that is grown in the saline-alkali soils of East Asia, where salinity is the limiting environmental factor. To study the defense mechanism of salt stress responses in water dropwort, we studied two water dropwort cultivars, V11E0022 and V11E0135, based on phenotypic and physiological indexes. We found that V11E0022 were tolerant to salt stress, as a result of good antioxidant defense system in the form of osmolyte (proline), antioxidants (polyphenols and flavonoids), and antioxidant enzymes (APX and CAT), which provided novel insights for salt-tolerant mechanisms. Then, a comparative transcriptomic analysis was conducted, and Gene Ontology (GO) analysis revealed that differentially expressed genes (DEGs) involved in the carbohydrate metabolic process could reduce oxidative stress and enhance energy production that can help in adaptation against salt stress. Similarly, lipid metabolic processes can also enhance tolerance against salt stress by reducing the transpiration rate, H2O2, and oxidative stress. Furthermore, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that DEGs involved in hormone signals transduction pathway promoted the activities of antioxidant enzymes and reduced oxidative stress; likewise, arginine and proline metabolism, and flavonoid pathways also stimulated the biosynthesis of proline and flavonoids, respectively, in response to salt stress. Moreover, transcription factors (TFs) were also identified, which play an important role in salt stress tolerance of water dropwort. The finding of this study will be helpful for crop improvement under salt stress.
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Deffo, Victor, Sylvie Hounzangbe-Adote, Raphiou Maliki, and H. H. M. Ould Ferroukh. "Evaluation participative ex ante de propositions de la recherche. Cas d’application dans le sud du Togo." Revue d’élevage et de médecine vétérinaire des pays tropicaux 64, no. 1-4 (January 1, 2011): 89. http://dx.doi.org/10.19182/remvt.10119.
Анотація:
L’objectif de cette étude a été d’expérimenter une méthode d’évaluation participative d’options techniques au sud du Togo. Pour répondre aux besoins face aux problèmes de fertilité des sols dans un contexte de systèmes mixtes agriculture élevage, des chercheurs ont évalué avec les diverses catégories d’acteurs le potentiel d’adoption de l’association du maïs, plante à fonction mixte alimentaire (grain) et fourragère (paille), et du Mucuna pruriens, légumineuse à cycle long employée comme fourrage et pour améliorer la fertilité des sols. L’association fertilisée avec des engrais chimiques a été dénommée MME ci-après. La méthode utilisée a mobilisé des outils d’analyse de la méthode active de recherche participative (MARP) et a compris quatre phases. La première correspondait à la description générale de l’ensemble de la région d’étude pour identifier des sites représentatifs à partir de la littérature et d’entretiens exploratoires. La seconde phase a permis la caractérisation de la diversité des producteurs à partir d’entretiens auprès des personnes ressources des sites retenus. La troisième phase a concerné la sélection participative d’un éventail d’options techniques comprenant l’association MME mais aussi des pratiques locales présentant des similitudes avec l’association MME, ainsi que d’autres propositions alternatives de la recherche pour améliorer la fertilité des sols et assurer l’alimentation fourragère des animaux. Cette sélection a été réalisée par un échantillon de producteurs représentatifs de leur diversité. Il leur a été demandé de hiérarchiser les différentes options techniques présentées lors de visites de parcelles expérimentales ou à l’aide de supports visuels. Ils ont utilisé des notes ou des cailloux compte tenu de la forte proportion d’illettrisme. La quatrième phase a été celle de l’évaluation aux dires de producteurs des effets perçus des différentes options sur la gestion des ressources agropastorales (eau, sol, biodiversité), leur acceptabilité ou leur rentabilité en fonction du coût de la main d’oeuvre. Cette méthode a été appliquée dans trois villages du sud du Togo. Dans ces villages, six principales catégories de producteurs ont été identifiées : les propriétaires terriens, les locataires de terres, les membres d’organisations paysannes, les producteurs lettrés, les producteurs illettrés, et les femmes. En plus du MME, six options ont été retenues dont l’association MME avec des variantes issues de pratiques locales, soit l’association maïs et Mucuna à cycle long mais sans l’usage d’engrais (MM), l’association maïs et Mucuna à cycle court et à base d’engrais (MMCE), l’association maïs et Mucuna à cycle court sans l’usage d’engrais (MMC), et maïs en culture seul avec apport massif d’engrais (ME). Les deux autres options ont été proposées par la recherche : maïs entouré de haies vives de légumineuses fourragères destinées à du bétail en stabulation contrôlée et dont le fumier était ensuite épandu au champ (MHF), et culture en couloirs de maïs et de Cajanus cajan. L’association MME a été l’option préférée des propriétaires terriens, des lettrés et des membres d’organisations paysannes. Chez les femmes, l’option privilégiée a été l’association MM compte tenu de leurs faibles ressources financières mais aussi de leur insécurité foncière. Chez les locataires des terres et les producteurs illettrés, l’option favorite a été l’association MMCE qui permettait le maintien de la seconde saison de culture. L’évaluation des différentes options a montré que l’association MME et l’option MHF ont été jugées par la majorité des catégories de producteurs comme ayant les effets les plus positifs sur les ressources agropastorales. Les associations MME et MMCE ont été considérées comme étant les plus acceptables socialement, notamment chez les propriétaires terriens mais aussi chez les vulgarisateurs, les consommateurs et les commerçants également interrogés ; venait ensuite l’option MHF. La rentabilité a été la meilleure pour les associations MM et MME et la plus faible pour les deux autres alternatives proposées par la recherche. Cette méthode d’évaluation permet de valoriser l’expertise des producteurs. Elle repose sur la perception que les producteurs ont des effets des technologies. Une perception positive constitue un des premiers facteurs d’adoption d’une proposition de la recherche. Mais pour cela du temps et des outils appropriés doivent être consacrés à l’étape de formation des producteurs sur les différentes options pour que cette perception ne soit pas biaisée par la qualité de l’information donnée par le chercheur. Cette évaluation permet en outre d’identifier ou d’adapter des variantes locales aux options pré-identifiées par les chercheurs. Les efforts de recherche-développement doivent se concentrer sur les processus de ces adaptations participatives.
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Noureddine, Nazhat-Ezzaman, Saïd Amrani, and Fatiha Aïd. "Statut symbiotique et souches de rhizobia associées à l’Acacia tortilis subsp. raddiana [Acacia raddiana s. s.], mimosoïdée des régions désertiques de l’Algérie." Botany 88, no. 1 (January 2010): 39–53. http://dx.doi.org/10.1139/b09-102.
Анотація:
L’ Acacia tortilis (Forsskal) Hayne subsp. raddiana (Savi) Brenan [ Acacia raddiana Savi s. s.] est la légumineuse ligneuse la plus répandue dans les régions désertiques d’Algérie. En tant qu’espèce bien adaptée, elle offre un potentiel d’intérêt pour le boisement ou le reboisement de ces régions. Sa capacité d’établir une symbiose fixatrice d’azote avec les rhizobia constitue un caractère important pour son développement et son adaptation aux conditions du milieu. Pour ces raisons, nous avons mené une étude portant sur la prévalence de la symbiose chez cette espèce et sur la caractérisation des souches de rhizobia associées. L’étude a porté sur 101 plants provenant de neuf sites naturels et de huit pépinières et nous a permis d’établir que l’A. tortilis subsp. raddiana est généralement nodulé et fixateur d’azote, malgré les conditions édaphiques défavorables qui prévalent en milieu naturel et dans les pépinières du sud du pays. La caractérisation symbiotique de 51 souches de rhizobia associées à l’A. tortilis subsp. raddiana nous a permis de montrer que celles-ci ne sont pas très spécifiques et qu’elles sont capables, pour la plupart, de former des nodules fixateurs d’azote chez les autres espèces d’acacias des régions désertiques de l’Algérie, en particulier l’ Acacia seyal Del. et l’ Acacia ehrenbergiana Hayne. Ces souches représentent donc un potentiel pour la production d’inoculants destinés à la bactérisation de l’A. tortilis subsp. raddiana, mais également des autres espèces d’acacias. L’analyse des profils de restriction du gène de l’ARN 16S des souches de rhizobia associées a permis de mettre en évidence leur grande diversité. Elles étaient représentées essentiellement par les espèces du genre Ensifer avec une prédominance de l’ Ensifer meliloti et, dans une moindre mesure, par des espèces des genres Mesorhizobium et Rhizobium , comme cela a déjà été rapporté par de nombreux auteurs dans d’autres régions d’Afrique. En plus des espèces de rhizobia reconnues comme étant capables de s’associer avec l’A. tortilis raddiana, nous avons isolé cinq souches que nous n’avons pas pu identifier, par réaction en chaîne de la polymérase – polymorphisme de la longueur du fragment de restriction du gène de l’ARN 16S, et qui pourraient constituer une nouvelle espèce génotypique.
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Snoussi, Hager, Hend Askri, Diana Nacouzi, Imen Ouerghui, Anthony Ananga, Asma Najar, and Walid El Kayal. "Comparative Transcriptome Profiling of Salinity-Induced Genes in Citrus Rootstocks with Contrasted Salt Tolerance." Agriculture 12, no. 3 (February 28, 2022): 350. http://dx.doi.org/10.3390/agriculture12030350.
Анотація:
Salinity is one of the most destructive environmental challenges for citriculture worldwide, and all climate change scenarios are predicting an increased impact of salinity on citrus orchards. Citrus cultivars are grown as grafts on various rootstocks to provide specific adaptation to abiotic stress and tolerance to major diseases such as citrus tristeza virus. To understand rootstock–scion interactions with regard to salinity, transcriptome profiling of mRNA expression was analyzed for 12 candidate genes in leaves, shoots, and roots of five Hernandina clementine scions grafted on Rangpur lime (LR), Volkamer lemon (CV), Carrizo citrange (CC), sour orange (Big), and Cleopatra mandarin (MC) rootstocks in response to moderate and severe salinity. qRT-PCR analysis revealed differential gene expression that varied by rootstock, salinity level, and tissue. The majority of induced genes were those involved in ion transporter proteins (mainly NHX1 and HKT1 genes), Cl− homeostasis (CCC1 gene), biosynthesis and accumulation of compatible osmolytes, proline (P5CS gene) and glycine betaine (CMO gene), accumulation of proteins (LEA2 gene), and ROS scavenging antioxidant activity (mainly APX). We show that these expression patterns could explain the relative tolerance of the used rootstocks and report new insights on the main salt tolerance mechanisms activated by these rootstocks.
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Sayers, Thomas D. J., Kim L. Johnson, Martin J. Steinbauer, Kevin Farnier, and Rebecca E. Miller. "Divergence in floral scent and morphology, but not thermogenic traits, associated with pollinator shift in two brood-site-mimicking Typhonium (Araceae) species." Annals of Botany 128, no. 3 (March 24, 2021): 261–80. http://dx.doi.org/10.1093/aob/mcab044.
Анотація:
Abstract Background Flowers which imitate insect oviposition sites probably represent the most widespread form of floral mimicry, exhibit the most diverse floral signals and are visited by two of the most speciose and advanced taxa of insect – beetles and flies. Detailed comparative studies on brood-site mimics pollinated exclusively by each of these insect orders are lacking, limiting our understanding of floral trait adaptation to different pollinator groups in these deceptive systems. Methods Two closely related and apparent brood-site mimics, Typhonium angustilobum and T. wilbertii (Araceae) observed to trap these distinct beetle and fly pollinator groups were used to investigate potential divergence in floral signals and traits most likely to occur under pollinator-mediated selection. Trapped pollinators were identified and their relative abundances enumerated, and thermogenic, visual and chemical signals and morphological traits were examined using thermocouples and quantitative reverse transcription–PCR, reflectance, gas chromatography–mass spectrometry, floral measurements and microscopy. Key Results Typhonium angustilobum and T. wilbertii were functionally specialized to trap saprophagous Coleoptera and Diptera, respectively. Both species shared similar colour and thermogenic traits, and contained two highly homologous AOX genes (AOX1a and AOX1b) most expressed in the thermogenic tissue and stage (unlike pUCP). Scent during the pistillate stage differed markedly – T. angustilobum emitted a complex blend of sesquiterpenes, and T. wilbertii, a dung mimic, emitted high relative amounts of skatole, p-cresol and irregular terpenes. The species differed significantly in floral morphology related to trapping mechanisms. Conclusions Functional specialization and pollinator divergence were not associated with differences in anthesis rhythm and floral thermogenic or visual signals between species, but with significant differences in floral scent and morphological features, suggesting that these floral traits are critical for the attraction and filtering of beetle or fly pollinators in these two brood-site mimics.
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Su, Zidong, Xiaojuan Huang, Qiuyi Zhong, Mili Liu, Xiaoyu Song, Jianni Liu, Aigen Fu, Jiangli Tan, Yixuan Kou, and Zhonghu Li. "Change of Potential Distribution Area of a Forest Tree Acer davidii in East Asia under the Context of Climate Oscillations." Forests 12, no. 6 (May 27, 2021): 689. http://dx.doi.org/10.3390/f12060689.
Анотація:
The climate oscillations of the quaternary periods have profoundly affected the geographic distributions of current species. Acer davidii is a deciduous forest tree species mainly distributed in East Asia and China, playing a dominant role in the local forest ecosystem. In order to study the potential changes of geographic distributions of A. davidii in climate fluctuations, we collected the relate geographical distribution data and six climatic variables, using maximum entropy modelling to determine the species distribution. The results showed that the Areas Under Curve (AUC) values of the working characteristic curves of the subjects in the five historical periods were all greater than 0.93, suggesting that the results of maximum entropy modelling were accurate. The simulation of species distribution showed that the suitable area of A. davidii was mainly concentrated in central and northern China in contemporary times. From the Last Interglacial Age (LIG) to the Last Glacial Maximum (LGM), and then to the future (2050, 2070), the distribution area of this species experienced a decrease (LGM~Current; the high adaptability areas of central China became moderate) then an increase (Current~2050, the adaptation areas expanded to South Asia, Southeast Asia, and Siberia), and finally decreased (2050~2070, the suitable areas of South Asia, Southeast Asia, and Siberia shrank returning to China at latitude 25 °N). Compared to the LGM, the area of contemporary suitable area increased. Interestingly, the area of suitable growth range under future climatic conditions (2050) increased by half than before, and the suitable distribution area moved from Midwest China to Northeast China. This study on the change of species distribution can provide a typical case for the model study on the response of plants to climate change in the north temperate and subtropical zones of East Asia. Meanwhile, it can also give a basis for planting planning, species protection, and management.
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Tan, Z. W., C. S. Wang, and G. L. Wang. "First Report of Bark Cracking of Koelreuteria bipinnata var integrifoliola Caused by Lasiodiplodia theobromae in China." Plant Disease 96, no. 10 (October 2012): 1579. http://dx.doi.org/10.1094/pdis-04-12-0337-pdn.
Анотація:
Koelreuteria bipinnata var integrifoliola is becoming a popular urban green tree in Ningbo City, Zhejiang Province, China, because of its adaptation ability to local conditions, fast growth, and beautiful appearance. A survey conducted from 2007 to 2010 revealed serious bark cracking on greenbelt trees approximately 15 to 16 years old that had been transplanted 5 to 6 years ago. Bark cracks increased in size over time, extending into the phloem and leading to extensive areas of bark loss with discoloration of the underlying xylem. Symptomatic trees had fewer new shoots in spring; many wilted and died in summer. Root rot was not observed in the withered trees but large light brown lesions were observed on cross sections of the main stem, each with a dark brown outer margin. In a September 2009 survey, 95% of symptomatic trees had stem lesions more than 50 cm long. Pieces of xylem (2 × 2 × 1 mm thick) were obtained from the margin of lesions surface sterilized using 0.1% mercuric chloride for 30 s, washed in sterile distilled water, and placed on 2% potato dextrose agar (PDA) at 28°C for 2 days. The fungus was then isolated and 12 colonies were obtrained. Three isolates KL-1-2, KL-3-2, and KL-4-3 were incubated on 2% PDA at 28°C for 30 days to produce spores. On PDA, the colonies were circular or near circular with irregular gray edges turning black green or black. The fungus also produced abundant aerial hyphae that were villous, septate, and irregular branched. Conidia were elliptical (or rounded) and hyaline when immature, becoming dark brown and septate longitudinally when mature and ranged from 23.2 to 27.0 × 10.8 to 16.2 μm (average 25.3 × 13.6 μm), similar to Lasiodiplodia theobromae (Patouillard) Griffon =Botryodiplodia theobromae Pa.t, Botryosphaeria rhodina (Berkeley & Curtis) von Arx (2). DNA extraction directly from the mycelium of KL-1-2, KL-3-2, and KL-4-3 was performed after 10 days' growth on PDA (1). The identities of the three isolates were confirmed by ITS1-5.8S-ITS2 rDNA sequence (GenBank Accession Nos. JN681172, JQ894322, and JQ894323, respectively) analysis that showed 99%, 100%, and 100% sequence similarity to L. theobromae xsd08006 (Accession No. FJ478102), L. theobromae PD20 (Accession No. GU251120), and L. theobromae xsd08008 (Accession No. EU918707), respectively. Pathogenicity tests were performed on 20 five-year-old K. bipinnata var integrifoliola plants by placing mycelia plugs of isolate KL-1-2 (10 × 10 mm) on the main trunk after wounding with a metal needle. Control plants received PDA plugs without mycelium. After inoculation, humidity was maintained using wet absorbent cotton and PE wrap film. Stem bark and phloem cracking was observed after 60 days on 85% of inoculated plants; 30% of those trees also had xylem discoloration. Symptoms were similar to those with natural infection. Control plants remained symptomless. The same fungus was reisolated from the brown xylem of inoculated plants. To our knowledge, this is the first report of bark cracking of K. bipinnata var integrifoliola caused by L. theobromae in China. References: (1) M.-J. Côté et al. Plant Dis. 88:1219, 2004. (2) G. Fu et al. Australas. Plant Dis. Notes 2:75, 2007.
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Liu, Yi-Ling, Zhi-Jun Shen, Martin Simon, Huan Li, Dong-Na Ma, Xue-Yi Zhu, and Hai-Lei Zheng. "Comparative Proteomic Analysis Reveals the Regulatory Effects of H2S on Salt Tolerance of Mangrove Plant Kandelia obovata." International Journal of Molecular Sciences 21, no. 1 (December 23, 2019): 118. http://dx.doi.org/10.3390/ijms21010118.
Анотація:
As a dominant mangrove species, Kandelia obovata is distributed in an intertidal marsh with an active H2S release. Whether H2S participates in the salt tolerance of mangrove plants is still ambiguous, although increasing evidence has demonstrated that H2S functions in plant responses to multiple abiotic stresses. In this study, NaHS was used as an H2S donor to investigate the regulatory mechanism of H2S on the salt tolerance of K. obovata seedlings by using a combined physiological and proteomic analysis. The results showed that the reduction in photosynthesis (Pn) caused by 400 mM of NaCl was recovered by the addition of NaHS (200 μM). Furthermore, the application of H2S enhanced the quantum efficiency of photosystem II (PSII) and the membrane lipid stability, implying that H2S is beneficial to the survival of K. obovata seedlings under high salinity. We further identified 37 differentially expressed proteins by proteomic approaches under salinity and NaHS treatments. Among them, the proteins that are related to photosynthesis, primary metabolism, stress response and hormone biosynthesis were primarily enriched. The physiological and proteomic results highlighted that exogenous H2S up-regulated photosynthesis and energy metabolism to help K. obovata to cope with high salinity. Specifically, H2S increased photosynthetic electron transfer, chlorophyll biosynthesis and carbon fixation in K. obovata leaves under salt stress. Furthermore, the abundances of other proteins related to the metabolic pathway, such as antioxidation (ascorbic acid peroxidase (APX), copper/zinc superoxide dismutase (CSD2), and pancreatic and duodenal homeobox 1 (PDX1)), protein synthesis (heat-shock protein (HSP), chaperonin family protein (Cpn) 20), nitrogen metabolism (glutamine synthetase 1 and 2 (GS2), GS1:1), glycolysis (phosphoglycerate kinase (PGK) and triosephosphate isomerase (TPI)), and the ascorbate–glutathione (AsA–GSH) cycle were increased by H2S under high salinity. These findings provide new insights into the roles of H2S in the adaptations of the K. obovata mangrove plant to high salinity environments.
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Wu, Jiaxu, Muhammad Nadeem, Lakshman Galagedara, Raymond Thomas, and Mumtaz Cheema. "Effects of Chilling Stress on Morphological, Physiological, and Biochemical Attributes of Silage Corn Genotypes During Seedling Establishment." Plants 11, no. 9 (April 29, 2022): 1217. http://dx.doi.org/10.3390/plants11091217.
Анотація:
Chilling stress is one of the major abiotic stresses which hinder seedling emergence and growth. Herein, we investigated the effects of chilling/low temperature stress on the morphological, physiological, and biochemical attributes of two silage corn genotypes during the seedling establishment phase. The experiment was conducted in a growth chamber, and silage corn seedlings of Yukon-R and A4177G-RIB were grown at optimum temperature up to V3 stage and then subjected to five temperature regimes (25 °C as control, 20 °C, 15 °C, 10 °C, and 5 °C) for 5 days. After the temperature treatment, the morphological, physiological, and biochemical parameters were recorded. Results indicated that temperatures of 15 °C and lower significantly affected seedling growth, photosynthesis system, reactive oxygen species (ROS) accumulation, and antioxidant enzyme activities. Changes in seedlings’ growth parameters were in the order of 25 °C > 20 °C > 15 °C > 10 °C > 5 °C, irrespective of genotypes. The chlorophyll content, photosynthetic rate, and maximal photochemical efficiency of PS-II (Fv/Fm) were drastically decreased under chilling conditions. Moreover, chilling stress induced accumulation of hydrogen peroxide (H2O2)and malonaldehyde (MDA) contents. Increased proline content and enzymatic antioxidants, including superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxide (APX), were found to alleviate oxidative damage under chilling stress. However, the genotype of Yukon-R exhibited better adaption to chilling stress than A4177G3-RIB. Yukon-R showed significantly higher proline content and enzymatic antioxidant activities than A4177G3-RIB under severe chilling conditions (temperature £ 10°C). Similarly, Yukon-R expressed low temperature-induced ROS accumulation. Furthermore, the interaction effects were found between temperature treatment and genotype on the ROS accumulation, proline content and antioxidant enzyme activities. In summary, the present study indicated that Yukon-R has shown better adaptation and resilience against chilling temperature stress, and therefore could be considered a potential candidate genotype to be grown in the boreal climate.
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Tredway, L. P. "First Report of Summer Patch of Creeping Bentgrass Caused by Magnaporthe poae in North Carolina." Plant Disease 89, no. 2 (February 2005): 204. http://dx.doi.org/10.1094/pd-89-0204a.
Анотація:
An unknown disease was observed in June 2002 and 2003 on creeping bentgrass (CRB [Agrostis stolonifera L.]) putting greens at The Country Club of Landfall in Wilmington, NC that were established in 2001 with a 1:1 blend of cvs. A-1 and A-4. Soil pH ranged from 7 to 8 at this location because of poor quality irrigation water. Symptoms appeared in circular patches of 0.3 to 1 m in diameter that exhibited signs of wilt followed by chlorosis and orange foliar dieback. The disease was initially diagnosed as take-all patch caused by Gaeumannomyces graminis (Sacc.) Arx & D. Olivier var. avenae (E.M. Turner) Dennis, based on the observation of necrotic roots and crowns that were colonized with dark, ectotrophic hyphae. However, the historical lack of take-all patch occurrence in this region led to the suspicion that G. graminis var. avenae was not involved. Sections of root and crown tissue were surface disinfested in 0.6% NaOCl for 5 min or 1% AgNO3 for 1 min and 5% NaCl for 30 s. Tissue was plated on SMGGT3 (2) or on potato dextrose agar containing 50 mg L-1 of tetracycline, streptomycin, and chloramphenicol. A fungus resembling Magnaporthe poae Landschoot & Jackson was consistently obtained regardless of isolation method. Teleomorph production was conducted on Sachs agar (4) overlaid with autoclaved wheat (Triticum aestivum L.) stem sections. Seven isolates were plated alone or paired with M. poae tester isolates 73-1 or 73-15 (3) and incubated at room temperature under continuous fluorescent illumination. Six isolates produced perithecia and ascospores typical of M. poae (3) when paired with 73-15 but not when plated alone or paired with 73-1; these isolates are, therefore, M. poae mating type ‘a’. Isolate TAP42 did not produce perithecia and remains unidentified. Cone-Tainers (3.8 × 20 cm) containing calcined clay were seeded with ‘A-4’ CRB (9.7 g cm-2) and inoculated 8 weeks later by placing four M. poae-infested rye (Secale cereale L.) grains below the soil surface. Inoculated Cone-Tainers were placed in growth chambers with 12-h day/night cycles at 30/25°C, 35/25°C, or 40/25°C. Field plots (1 m2) of ‘A-4’ CRB in Jackson Springs, NC were inoculated on 19 June 2003 by removing a soil core (1.9 × 10.3 cm) from the center of each plot, adding 25 cm3 of M. poae-infested rye grains, and then capping the hole with sand. Growth chamber and field inoculations were arranged in a randomized complete block with four replications. Eight weeks after inoculation in the growth chamber, isolates TAP35, TAP41, and SCR4 caused significant foliar chlorosis and dieback at 12-h day/night cycles of 30/25°C and 35/25°C, but only TAP41 induced symptoms at 40/25°C. Isolate TAP42 did not induce symptoms at any temperature regimen. Orange patches (10 to 15 cm in diameter) were observed in field plots inoculated with TAP41 on 27 August 2003. No other isolates induced aboveground symptoms. Roots and crowns of plants exhibiting foliar symptoms in the greenhouse and field were necrotic and colonized with ectotrophic hyphae, and M. poae was consistently isolated from this tissue. Although M. poae has been associated with CRB in Florida (1), to our knowledge, this is the first report of summer patch of CRB within the normal zone of adaptation for this turfgrass species. Observation of this disease highlights the need for accurate methods for diagnosis of diseases caused by ectotrophic root-infecting fungi. References: (1) M. L. Elliott. Plant Dis. 77:429, 1993. (2) M. E. Juhnke et al. Plant Dis. 68:233, 1984. (3) P. J. Landschoot and N. Jackson. Mycol. Res. 93:59, 1989. (4) E. S. Lutrell. Phytopathology 48:281, 1958.
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Freire, Fátima Conceição de Jesus, Juliana da Silva-Pinheiro, Jayne Silva Santos, Arthur Gomes Lima da Silva, Liliane Santos de Camargos, Lauricio Endres, and Gilberto Costa Justino. "Proline and antioxidant enzymes protect Tabebuia aurea (Bignoniaceae) from transitory water deficiency." Rodriguésia 73 (2022). http://dx.doi.org/10.1590/2175-7860202273031.
Анотація:
Abstract Water deficiency is a major abiotic stress that limits biomass production and drives plant species distributions. We evaluate the effects of water deficiency on ecophysiological and biochemical parameters of seedlings of Tabebuia aurea. Plants were subjected to daily watering (control) and to stress by soil water deficiency for 29 days. Leaf area, plant biomass, gas exchange, SPAD index, maximum quantum yield (Fv / Fm), quantum yield of PSII (ΦPSII), superoxide dismutase (SOD) and L-ascorbate peroxidase (APX) activity, lipid peroxidation, and proline content were recorded. Plants responded to water deficit by reducing leaf area and accumulating proline. Stomatal conductance was reduced to limit the water loss by transpiration. However, limiting CO2 uptake caused reduction in photosynthesis and biomass. The excess of energy unutilized by photosynthesis reduced SPAD index and ΦPSII. As a result, we observed an increase in SOD and APX activity, protecting chloroplast membranes from further damages caused by lipid peroxidation. Our results indicate that T. aurea have capacity to survive under water deficiency reducing stomatal aperture, but affecting the rate of CO2 assimilation. Nevertheless, plants showed mechanisms to preventing damages to the photosynthetic apparatus. Such plasticity is an important adaptation for plants growing in dry environmental.
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Khan, Rayyan, Xinghua Ma, Shahen Shah, Xiaoying Wu, Aaqib Shaheen, Lixia Xiao, Yuanhua Wu, and Shusheng Wang. "Drought-hardening improves drought tolerance in Nicotiana tabacum at physiological, biochemical, and molecular levels." BMC Plant Biology 20, no. 1 (October 23, 2020). http://dx.doi.org/10.1186/s12870-020-02688-7.
Анотація:
Abstract Background Drought stress is the most harmful one among other abiotic stresses with negative impacts on crop growth and development. Drought-hardening is a feasible and widely used method in tobacco seedlings cultivation. It has gained extensive interests due to its role in improving drought tolerance. This research aimed to investigate the role of drought-hardening and to unravel the multiple mechanisms underlying tobacco drought tolerance and adaptation. Results This study was designed in which various drought-hardening treatments (CK (no drought-hardening), T1 (drought-hardening for 24 h), T2 (drought-hardening for 48 h), and T3 (drought-hardening for 72 h)) were applied to two tobacco varieties namely HongHuaDaJinYuan (H) and Yun Yan-100 (Y). The findings presented a complete framework of drought-hardening effect at physiological, biochemical, and gene expression levels of the two tobacco varieties under drought stress. The results showed that T2 and T3 significantly reduced the growth of the two varieties under drought stress. Similarly, among the various drought-hardening treatments, T3 improved both the enzymatic (POD, CAT, APX) and non-enzymatic (AsA) defense systems along with the elevated levels of proline and soluble sugar to mitigate the negative effects of oxidative damage and bringing osmoregulation in tobacco plants. Finally, the various drought-hardening treatments (T1, T2, and T3) showed differential regulation of genes expressed in the two varieties, while, particularly T3 drought-hardening treatment-induced drought tolerance via the expression of various stress-responsive genes by triggering the biosynthesis pathways of proline (P5CS1), polyamines (ADC2), ABA-dependent (SnRK2, AREB1), and independent pathways (DREB2B), and antioxidant defense-related genes (CAT, APX1, GR2) in response to drought stress. Conclusions Drought-hardening made significant contributions to drought tolerance and adaptation in two tobacco variety seedlings by reducing its growth and, on the other hand, by activating various defense mechanisms at biochemical and molecular levels. The findings of the study pointed out that drought-hardening is a fruitful strategy for conferring drought tolerance and adaptations in tobacco. It will be served as a useful method in the future to understand the drought tolerance and adaptation mechanisms of other plant species. Graphical abstract Drought-hardening improved drought tolerance and adaptation of the two tobacco varieties. T1 indicates drought-hardening for 24 h, T2 indicates drought-hardening for 48 h, T3 indicates drought-hardening for 72 h
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Wojciechowska, Daria, Andonis Karachitos, Milena Roszkowska, Wiktor Rzeźniczak, Robert Sobkowiak, Łukasz Kaczmarek, Jakub Z. Kosicki, and Hanna Kmita. "Mitochondrial alternative oxidase contributes to successful tardigrade anhydrobiosis." Frontiers in Zoology 18, no. 1 (April 1, 2021). http://dx.doi.org/10.1186/s12983-021-00400-5.
Анотація:
AbstractAnhydrobiosis can be described as an adaptation to lack of water that enables some organisms, including tardigrades, to survive extreme conditions, even some that do not exist on Earth. The cellular mechanisms underlying anhydrobiosis are still not completely explained including the putative contribution of mitochondrial proteins. Since mitochondrial alternative oxidase (AOX), described as a drought response element in plants, was recently proposed for various invertebrates including tardigrades, we investigated whether AOX is involved in successful anhydrobiosis of tardigrades.Milnesium inceptumwas used as a model for the study. We confirmed functionality ofM. inceptumAOX and estimated its contribution to the tardigrade revival after anhydrobiosis of different durations. We observed that AOX activity was particularly important forM. inceptumrevival after the long-term tun stage but did not affect the rehydration stage specifically. The results may contribute to our understanding and then application of anhydrobiosis underlying mechanisms.
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Hao, Suxiao, Yanfen Lu, Zhen Peng, Enying Wang, Linke Chao, Silin Zhong, and Yuncong Yao. "McMYB4 improves temperature adaptation by regulating phenylpropanoid metabolism and hormone signaling in apple." Horticulture Research 8, no. 1 (August 1, 2021). http://dx.doi.org/10.1038/s41438-021-00620-0.
Анотація:
AbstractTemperature changes affect apple development and production. Phenylpropanoid metabolism and hormone signaling play a crucial role in regulating apple growth and development in response to temperature changes. Here, we found that McMYB4 is induced by treatment at 28 °C and 18 °C, and McMYB4 overexpression results in flavonol and lignin accumulation in apple leaves. Yeast one-hybrid (Y1H) assays and electrophoretic mobility shift assays (EMSAs) further revealed that McMYB4 targets the promoters of the flavonol biosynthesis genes CHS and FLS and the lignin biosynthesis genes CAD and F5H. McMYB4 expression resulted in higher levels of flavonol and lignin biosynthesis in apple during growth at 28 °C and 18 °C than during growth at 23 °C. At 28 °C and 18 °C, McMYB4 also binds to the AUX/ARF and BRI/BIN promoters to activate gene expression, resulting in acceleration of the auxin and brassinolide signaling pathways. Taken together, our results demonstrate that McMYB4 promotes flavonol biosynthesis and brassinolide signaling, which decreases ROS contents to improve plant resistance and promotes lignin biosynthesis and auxin signaling to regulate plant growth. This study suggests that McMYB4 participates in the abiotic resistance and growth of apple in response to temperature changes by regulating phenylpropanoid metabolism and hormone signaling.
45
Pei, Leo, and Servanne Woodward. "Voltaire traducteur de Shakespeare—légitimités et illégitimités interprétatives." Le Monde français du dix-huitième siècle 7, no. 1 (April 18, 2022). http://dx.doi.org/10.5206/mfdsecfw.v7i1.14859.
Анотація:
On the surface, adaptations did not necessarily look different from literal, accurate translations of prose fiction in the 18th century. Picking up a romance or novel whose title page indicated a foreign source, no eighteenth-century reader could be assured that it truly reflected the original,” explique Mary Helen McMurran. En fait le siècle va alterner entre deux partis, celui de l’adaptation ou traduction libre de « belles infidèles » faites pour plaire au public français, et celui plus rare, de la traduction fidèle, souvent littérale.
Constance B. West fait la liste de ce qu’il s’agit de retrancher des textes anglais : la mention des plantes et des animaux, de la nature, les termes didactiques et les métaphores de la marine et du commerce. Elle évalue aussi la proposition de Le Tourneur, que la traduction soit une espèce de tri au goût des Français. Il faut faire preuve de discernement, de prudence lorsqu’on cède à la curiosité d’examiner « l’air étranger » qui comporte le risque de contaminer ou pervertir le goût français, ou pour Voltaire la Modernité (Lettre XVIII des Lettres philosophiques). West nous aiderait à situer Voltaire aux côtés de Turgot qui prône la traduction littérale, ainsi que de Dupont de Neymour, Saint-Simon, Diderot, et Mme de Staël. Qu’en est-il lorsque Voltaire traduit Jules César ?
46
Abdirad, Somayeh, Mohammad Reza Ghaffari, Ahmad Majd, Saeed Irian, Armin Soleymaniniya, Parisa Daryani, Parisa Koobaz, et al. "Genome-Wide Expression Analysis of Root Tips in Contrasting Rice Genotypes Revealed Novel Candidate Genes for Water Stress Adaptation." Frontiers in Plant Science 13 (February 21, 2022). http://dx.doi.org/10.3389/fpls.2022.792079.
Анотація:
Root system architecture (RSA) is an important agronomic trait with vital roles in plant productivity under water stress conditions. A deep and branched root system may help plants to avoid water stress by enabling them to acquire more water and nutrient resources. Nevertheless, our knowledge of the genetics and molecular control mechanisms of RSA is still relatively limited. In this study, we analyzed the transcriptome response of root tips to water stress in two well-known genotypes of rice: IR64, a high-yielding lowland genotype, which represents a drought-susceptible and shallow-rooting genotype; and Azucena, a traditional, upland, drought-tolerant and deep-rooting genotype. We collected samples from three zones (Z) of root tip: two consecutive 5 mm sections (Z1 and Z2) and the following next 10 mm section (Z3), which mainly includes meristematic and maturation regions. Our results showed that Z1 of Azucena was enriched for genes involved in cell cycle and division and root growth and development whereas in IR64 root, responses to oxidative stress were strongly enriched. While the expansion of the lateral root system was used as a strategy by both genotypes when facing water shortage, it was more pronounced in Azucena. Our results also suggested that by enhancing meristematic cell wall thickening for insulation purposes as a means of confronting stress, the sensitive IR64 genotype may have reduced its capacity for root elongation to extract water from deeper layers of the soil. Furthermore, several members of gene families such as NAC, AP2/ERF, AUX/IAA, EXPANSIN, WRKY, and MYB emerged as main players in RSA and drought adaptation. We also found that HSP and HSF gene families participated in oxidative stress inhibition in IR64 root tip. Meta-quantitative trait loci (QTL) analysis revealed that 288 differentially expressed genes were colocalized with RSA QTLs previously reported under drought and normal conditions. This finding warrants further research into their possible roles in drought adaptation. Overall, our analyses presented several major molecular differences between Azucena and IR64, which may partly explain their differential root growth responses to water stress. It appears that Azucena avoided water stress through enhancing growth and root exploration to access water, whereas IR64 might mainly rely on cell insulation to maintain water and antioxidant system to withstand stress. We identified a large number of novel RSA and drought associated candidate genes, which should encourage further exploration of their potential to enhance drought adaptation in rice.
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Popov, Vasily N., Mikhail Y. Syromyatnikov, Alisdair R. Fernie, Subhra Chakraborty, Kapuganti Jagadis Gupta, and Abir U. Igamberdiev. "The uncoupling of respiration in plant mitochondria: keeping reactive oxygen and nitrogen species under control." Journal of Experimental Botany, November 27, 2020. http://dx.doi.org/10.1093/jxb/eraa510.
Анотація:
Abstract Plant mitochondrial respiration involves the operation of various alternative pathways. These pathways participate, both directly and indirectly, in the maintenance of mitochondrial functions though they do not contribute to energy production, being uncoupled from the generation of an electrochemical gradient across the mitochondrial membrane and thus from ATP production. Recent findings suggest that uncoupled respiration is involved in reactive oxygen species (ROS) and nitric oxide (NO) scavenging, regulation, and homeostasis. Here we discuss specific roles and possible functions of uncoupled mitochondrial respiration in ROS and NO metabolism. The mechanisms of expression and regulation of the NDA-, NDB- and NDC-type non-coupled NADH and NADPH dehydrogenases, the alternative oxidase (AOX), and the uncoupling protein (UCP) are examined in relation to their involvement in the establishment of the stable far-from-equilibrium state of plant metabolism. The role of uncoupled respiration in controlling the levels of ROS and NO as well as inducing signaling events is considered. Secondary functions of uncoupled respiration include its role in protection from stress factors and roles in biosynthesis and catabolism. It is concluded that uncoupled mitochondrial respiration plays an important role in providing rapid adaptation of plants to changing environmental factors via regulation of ROS and NO.
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Yang, Jiali, Wenhui Gu, Zezhong Feng, Bin Yu, Jianfeng Niu, and Guangce Wang. "Synthesis of Abscisic Acid in Neopyropia yezoensis and Its Regulation of Antioxidase Genes Expressions Under Hypersaline Stress." Frontiers in Microbiology 12 (January 10, 2022). http://dx.doi.org/10.3389/fmicb.2021.775710.
Анотація:
Abscisic acid (ABA) is regarded as crucial for plant adaptation to water-limited conditions and it functions evolutionarily conserved. Thus, insights into the synthesis of ABA and its regulation on downstream stress-responsive genes in Neopyropia yezoensis, a typical Archaeplastida distributed in intertidal zone, will improve the knowledge about how ABA signaling evolved in plants. Here, the variations in ABA contents, antioxidant enzyme activities and expression of the target genes were determined under the presence of exogenous ABA and two specific inhibitors of the ABA precursor synthesis. ABA content was down-regulated under the treatments of each or the combination of the two inhibitors. Antioxidant enzyme activities like SOD, CAT and APX were decreased slightly with inhibitors, but up-regulated when the addition of exogenous ABA. The quantitative assays using real-time PCR (qRT-PCR) results were consistent with the enzyme activities. All the results suggested that ABA can also alleviate oxidative stress in N. yezoensis as it in terrestrial plant. Combined with the transcriptome assay, it was hypothesized that ABA is synthesized in N. yezoensis via a pathway that is similar to the carotenoid pathway in higher plants, and both the MVA and that the MEP pathways for isoprenyl pyrophosphate (IPP) synthesis likely exist simultaneously. The ABA signaling pathway in N. yezoensis was also analyzed from an evolutionary standpoint and it was illustrated that the emergence of the ABA signaling pathway in this alga is an ancestral one. In addition, the presence of the ABRE motif in the promoter region of antioxidase genes suggested that the antioxidase system is regulated by the ABA signaling pathway.