Genomics of Plant Stress Tolerance

这项提议的长期目标是鉴定和确定所有基因在植物对盐和水胁迫的反应中所起的作用。在过去的十年中，人们已经清楚地认识到，对水分亏缺和离子失衡的反应是由复杂的分子和生化信号转导过程控制的，这些过程协调地决定了整个植物水平上的耐受性或敏感性。然而，在过去的五年中，基因组学、信息学和功能基因组学的进步使得对基因补体或基因集的全面了解在技术上是可行的，这些基因补体或基因集集成在一起，影响非生物胁迫耐受性。为了以最有效、最全面和最综合的方式解决高等植物这种耐受性的遗传基础。R. Bressan， P. Hasegawa（普渡大学），R. Burnap， J. Cushman， R. Prade（俄克拉荷马州立大学）和H. Bohnert， D. Gaibraith， J. k .。朱先生（亚利桑那大学）组成了一个联盟。每个参与者在这一研究领域都有记录在案的丰富经验，并且在过去或现在的许多情况下都有生产力的记录。该团队将采用三种不同但互补的方法来分离、表征和评估胁迫相关的核心基因集的功能，这些基因集为植物耐水和盐胁迫表型提供了基础。第一种方法将包括在经过充分研究的模式生物（聚胞菌PCC6803、酿酒酵母、芽曲霉和拟南芥）中通过随机和靶向诱变策略对胁迫耐受重要基因的功能鉴定。对于拟南芥，他们将从大量的胁迫耐受性或信号缺陷突变体中识别、定位和克隆遗传Ioci。由此产生的突变体集将用于利用高等植物来源的基因进行互补研究。第二种方法旨在利用EST测序和微阵列分析，从敏感植物（拟南芥和水稻）和抗性植物（盐盐杜氏藻和冰草）中确定与胁迫相关的核心转录本。这种方法将侧重于对盐和干旱敏感和耐药生物的基因表达模式的比较研究，因为最近对耐药生物的研究表明，在敏感生物中存在不存在或不适当表达的耐胁迫机制。第三种方法将通过使用启动子捕获方法和功能获得研究来监测原位本地化，从而扩展应力相关转录本的功能分析。这些方法代表了该中心内各个小组正在进行的工作的逻辑扩展。他们将通过日常的互动、研讨会/会议和在成员实验室为学生和博士后延长的工作时间来促进联盟活动的互动和整合，以确保新一代的研究人员在多方面和跨学科的问题解决方面得到培训。根据美国农业部的统计数据，非生物胁迫对作物生产力的影响是显著的，占农业产量减少的三分之二。这一建议非常及时，结合了独特的专业知识，是假设驱动的，最终达到了一个明确的目标——理解构成植物非生物逆境耐受性的基因的数量、性质和网络以及生理机制。

The long-term goal of this proposal is to identify and determine the role of all the genes involved in a plants response to salt and water stress. Over the last decade, it has become clear that responses to water deficit and ion imbalance are governed by complex molecular and biochemical signal transduction processes, which coordinately act to determine tolerance or sensitivity at the whole-plant levet. Within the last five years, however, advances in genomics, informatics, and functional genomics have made it technically feasible to gain a global understanding of the gene complement or set that becomes integrated to effect abiotic stress tolerance. To tackle the genetic basis of this tolerance in higher plants in the most efficient, comprehensive, and integrative way possible Drs. R. Bressan, P. Hasegawa ( Purdue University), R. Burnap, J. Cushman, R. Prade (Oklahoma State University) and H. Bohnert, D. Gaibraith, J-K. Zhu (University of Arizona) have formed a consortium. Each participant has a documented and extensive experience in this research area with a proven record of productivity and in many instances past or present collaborations.This team will employ three distinct, yet complementary approaches to isolate, characterize, and assess the function of the core set of stress-related genes that provide the basis for the water and salt stress tolerance phenotype in plants.The first approach will encompass the functional identification of genes important to stress tolerance by random and targeted mutagenesis strategies in well-studied model organisms (Synechocystis PCC6803, Saccharomyces cerevisiae, Aspergillus nidulans, and Arabidopsis thaliana). For Arabidopsis, they will identify, map and clone genetic Ioci from a large set of mutants defective in stress tolerance or signaling. The resulting sets of mutants will be used for complementation studies using genes from higher plant sources.The second approach aims to define the core set of stress-related transcripts from both sensitive plants (Arabidopsis thaliana and rice) and resistant plants (Dunaliella salina and ice plant) using EST sequendng and microarray analysis. This approach will focus on the comparative study of gene expression patterns in salt and drought sensitive and resistant organisms, since recent studies of resistant organisms have revealed the existence of mechanisms of stress tolerance not present or not appropriately expressed in sensitive organisms.The third approach will extend the functional analysis of stress-related transcripts by monitoring in situ Iocalizations by using promoter trapping approaches and gain-of-function studies.These approaches represent logical extensions of ongoing work in individual groups within this center. They will foster interaction and integration of Consortium activities through daily interactions, workshops/meetings and extended work periods in member laboratories for their students and postdoctoral fellows to ensure a new generation of researchers trained in multi-faceted and interdisciplinary problem solving. The impact of abiotic stress on crop productivity is remarkable according to USDA statistics and amounts to two-thirds of all yield reductions in agriculture. This proposal is exceptionally timely, combines unique expertise, is hypothesis-driven and culminates in a dearly defined goal - understanding the number, nature and networking of genes and physiological mechanisms that constitute plant abiotic stress tolerance.