CAREER: The Adaptation of Plant Development to Environmental Stress

马拉美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械来适应环境压力具有巨大的潜力，可以作为提高作物产量和扩大作物生长地理范围的一种战略。一种植物适应机制是根据资源的可获得性和分布来优化器官数量和位置。尽管这种发育反应很重要，但形态适应背后的分子机制基本上是未知的。首席研究员发现，模式植物拟南芥的侧根发育受到轻度干旱胁迫的显著抑制，为研究适应提供了一个模型。为此，她的实验室分离出了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的研究，他们定义了引导根系适应的LRD途径。该途径的主要特征是：(1)植物激素脱落酸(ABA)和生长素(IAA)在介导该途径的过程中起着关键的相反作用；(2)LRD突变体在ABA介导的几种反应中表现出异常的表型，包括对脱水的显著耐受性；(3)ERECTA基因在侧根形成的渗透抑制中发挥重要作用。基于这些发现，研究人员将表征LRD和ERECTA基因在适应中的功能，并研究激素积累和定位在LRD途径中的作用。该项目的长期目标是学习如何利用植物与生俱来的能力来适应环境压力，以改善作物。首席研究员对解决全球粮食短缺问题的创新方法的兴趣也促使她设计了一门课程，让学生接触到这个复杂的问题。这门课程的目的是让来自许多学科的高水平本科生能够亲自投入到具有全球重要性的问题上，如饥荒和粮食分配不均。与多学科教师团队合作，学生将学习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让学生参与教师进行的研究项目，并有机会在课程范围之外继续进行这项研究。这种对这一全球问题的早期认识和参与有望影响学生的职业选择，引导他们进入将在向受灾地区提供足够食物方面产生进一步知识和进展的领域。

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.