CAREER: The Adaptation of Plant Development to Environmental Stress

[238529]植物的生存取决于对不利条件的适应。利用植物自身的复杂机制来适应环境胁迫，作为提高作物产量和扩大作物生长地理范围的一种策略，具有巨大的潜力。植物的一种适应机制是根据资源的可用性和分布来优化器官的数量和位置。尽管这种发育反应的重要性，但形态适应的分子机制基本上是未知的。作者发现模式植物拟南芥侧根的发育在轻度干旱胁迫下受到显著抑制，为研究适应提供了一个模型。为此，她的实验室已经分离出在这种反应中有缺陷的侧根发育（lrd）突变体。基于野生型和突变体研究，他们定义了指导根系适应的LRD途径。该通路的主要特征有：(1)植物激素脱落酸（ABA）和生长素（IAA）在该通路的介导中起关键的拮抗作用；(2) lrd突变体在一些aba介导的反应中表现出异常表型，包括对脱水的明显耐受性；(3) ERECTA基因编码一种被认为是茎特异性受体蛋白激酶，在渗透抑制侧根形成中起重要作用。基于这些发现，研究人员将对LRD和ERECTA基因在适应中的功能进行表征，并研究激素积累和定位在LRD通路中的作用。该项目的长期目标是学习如何利用植物天生的适应环境压力的能力来改善作物。首席研究员对解决全球粮食短缺问题的创新方法感兴趣，这也促使她设计了一门课程，让学生了解这个复杂的问题。该课程旨在让来自多个学科的高级本科生能够亲自参与到饥荒和粮食分配不均等具有全球重要性的问题中来。学生将与多学科的教师团队合作，了解与世界饥饿有关的生物、政治和经济问题，并讨论可能的解决方案。本课程的一个关键部分将是学生参与由导师进行的研究项目，并有机会在本课程范围之外继续进行研究。这种对这一全球性问题的早期认识和参与有望影响学生的职业选择，引导他们进入能够在向受灾地区提供充足食物方面产生进一步知识和进步的领域。

0238529MalamyPlant survival depends on adaptation to adverse conditions. Harnessing the plant's own complex machinery for adaptation to environment stresses has tremendous potential as a strategy for improvement of crop yields and extending the geographical range for crop growth. One plant adaptation mechanism is to optimize organ number and location in accordance with the availability and distribution of resources. Despite the importance of this developmental response, the molecular mechanisms that underlie morphological adaptation are essentially unknown. The Principal Investigator has found that the development of lateral roots in the model plant Arabidopsis thaliana is dramatically repressed by mild drought stress, providing a model in which to study adaptation. To this end, her lab has isolated lateral root development (lrd) mutants that are defective in this response. Based on wild-type and mutant studies, they have defined the LRD pathway that directs root system adaptation. Key feature of the pathway are: (1) the plant hormones abscicic acid (ABA) and auxin (IAA) play critical opposing roles in mediating the pathway; (2) lrd mutants show aberrant phenotypes in several ABA-mediated responses, including a marked tolerance to dehydration; and (3) the ERECTA gene, which encodes a putative shoot-specific receptor protein kinase, plays an essential role in the osmotic repression of lateral root formation. Based on these findings, the researchers will characterize the function of the LRD and ERECTA genes in adaptation, and study the role of hormone accumulation and localization in the LRD pathway. The long-term goal of the project is to learn how to use a plant's innate ability to adjust to environmental stress for crop improvement. The Principal Investigator's interest in innovative approaches to solving the worldwide problem of food deficit has also led her to design a course to expose students to this complex problem. The course is designed to allow upper level undergraduates from many disciplines to become personally invested in issues of global importance such as famine and unequal distribution of food. Working with a multi-disciplinary team of instructors, students will learn about the biological, political and economic issues involved in world hunger and discuss possible solutions. A key part of this course will be the involvement of students in research projects conducted by the instructors, and the opportunity to continue this research beyond the scope of the class. Such early awareness and involvement in this global problem will hopefully influence students in their career choices, guiding them into areas which will generate further knowledge and progress in providing adequate food to afflicted areas.