Cellular Mechanisms of Abiotic Stress Tolerance in Plants

作为固着生物，植物不断受到各种生物和非生物胁迫，限制其生长甚至导致死亡。在农业方面，环境压力，如极端温度，高盐干旱和病原体攻击，是产量损失的主要原因，通过降低全球范围内的作物性能，约。20%的遗传潜能。全球气候变化和天气波动必然会广泛增加生产不稳定性并使自然资源退化，这进一步加剧了这一问题。为了应对农业生产的这些主要制约因素，开发耐受环境胁迫的作物，从而确保在恶劣条件下的生产力，对植物研究人员来说已经变得至关重要。为了实现这一重要的长期目标，对适应不同环境胁迫的野生物种（如模式植物拟南芥）的研究对于提供遗传资源和拓宽栽培作物狭窄的遗传基础至关重要。此外，通过育种提高胁迫耐受性还需要详细了解各种基因和蛋白质在胁迫事件期间细胞膜损伤控制中的作用，这是植物胁迫耐受性所需的第一个细胞反应之一。 本文提出的研究计划将利用模式植物拟南芥的资源来鉴定和表征植物非生物胁迫耐受性的细胞机制。具体来说，我们将研究最近发现的植物蛋白家族，synaptotagmin家族，它介导的膜融合所需的维持植物细胞的结构完整性，在压力事件。我们还将鉴定在恶劣条件下不能保持细胞膜完整性的拟南芥突变体，并分离出耐受非生物胁迫所需的相应基因。使用这些方法，我们建议研究：1）在植物细胞膜的单一和组合的环境应力的具体影响，2）在应力条件下维持细胞稳定性所需的膜的生物化学性质，3）突触结合蛋白控制膜融合的亚细胞机制，4）额外的蛋白质成分的身份参与膜的稳定性和修复过程中的压力事件。了解细胞膜稳定性和修复所涉及的亚细胞机制和蛋白质，将使未来能够开发耐胁迫作物，确保在不利环境条件下的高产量，以实现长期可持续农业。

Being sessile organisms, plants are continuously exposed to various biotic and abiotic stresses that limit their growth or even cause death. In agricultural terms, environmental stresses such as extreme temperatures, high salinity drought, and pathogen attacks constitute the principal cause of yield loss by diminishing crop performance worldwide to ca. 20% of their genetic potential. This problem is further exacerbated by the global climate change and weather fluctuations bound to widely increase production instability and to degrade natural resources. To cope with these major constraints to agricultural production, the development of crops that are tolerant to environmental stresses, and therefore ensure productivity under harsh conditions, has become of paramount importance for plant researchers. To achieve this important long-term goal, the study of wild species adapted to different environmental stresses, such as the model plant Arabidopsis thaliana, is essential to provide genetic resources and broaden the narrow genetic base of cultivated crops. Moreover, the enhancement through breeding of stress tolerance traits will also require a detailed understanding of the roles of various genes and proteins in cell membrane damage control during stress episodes, one of the first cellular responses required for the plant stress tolerance. The research program proposed here will use the resources from the model plant Arabidopsis thaliana to identify and characterize the cellular mechanisms underlying abiotic stress tolerance in plants. Specifically, we will study a recently discovered family of plant proteins, the synaptotagmin family, which mediates the membrane fusions required to maintain the structural integrity of plant cells during stress episodes. We will also identify Arabidopsis mutants unable to maintain the cellular membrane integrity under harsh conditions, and we will isolate the corresponding genes needed for the tolerance to abiotic stresses. Using these approaches we propose to study: 1) The specific effects of single and combined environmental stresses in plant cell membranes, 2) The biochemical properties of the membranes required to maintain cellular stability under stress conditions, 3) The subcellular mechanisms by which synaptotagmins control membrane fusions, 4) The identity of additional protein components involved in membrane stability and repair during stress episodes. Knowledge about the subcellular mechanisms and proteins involved in cellular membranes stability and repair will enable the future development of stress-tolerant crops, ensuring high yield under adverse environmental conditions for a long-term sustainable agriculture.