LiT: RUI: Effects of Heat Stress on Hormonal Signaling in a Thermotolerant Equatorial Perennial Plant, Nicotiana Glauca (Graham)

许多生活在炎热气候下的多年生植物已经进化到能够在极端高温下生存。据推测，随着下个世纪全球气候变化，温度将会温和地升高5-6ºC，但对这些植物影响不大。然而，对这种温度升高对植物细胞生长在其热生存极限附近的影响的研究表明，情况并非如此，并导致了这个项目。植物的生长是通过现有细胞的分裂，然后扩大较小的、新形成的细胞。研究表明，5-6℃的温度升高会阻断一种关键生长激素——生长素的作用，而在较低的温度下，生长素会激活植物细胞分裂和生长所需的基因。在这个项目中，将确定5-6℃的温度升高是否会阻断生长素激活控制完整植物细胞分裂和生长的基因的能力。研究人员还将研究温度升高是否会通过抑制一种叫做Rac GTPase的特殊酶来阻止生长素的作用，这种酶是导致生长素激活反应的一系列事件中的一种重要蛋白质。更广泛的影响：这项研究将在一个小型本科学院的生物系进行，教职员工和学生共同参与研究。该项目将通过以下方式鼓励本科生从事研究工作：(1)每年招募和培训两名学生进行研究；(2)开展学生间的合作研究项目；(3)创建以学生为主导的科学阅读小组；(4)安排由学生主持的著名科学家访问，他们将与学生和教师就研究进行磋商。将举办一个区域教师研讨会，主题是将研究融入本科教学。本研究对本地耐热植物和可能依赖于它们的动物的保护管理具有启示意义。它也可以应用于开发耐热多年生作物和观赏植物的基因工程策略。

Many perennial plants that live in hot climates have evolved to survive heat extremes. It is assumed that the seemingly modest temperature increases of 5-6ºC predicted to accompany the next century of global climate change will have little effect on these plants. However, research on the effects of such temperature increases on plant cells growing near their thermal survival limits suggests otherwise, and has led to this project. Plants grow by the division of existing cells, and then enlarging the smaller, newly-formed cells. It has been shown that 5-6ºC temperature increases block the action of a critical growth hormone, auxin, that at lower temperatures activates genes required for plant cells to divide and grow. In this project it will be determined whether 5-6ºC temperature increases block auxin's ability to activate genes that control cell division and growth in intact plants. It will also be examined whether temperature increases block auxin action by inhibiting one particular enzyme called a Rac GTPase, an important protein in the chain of events that leads to the auxin-activated responses. Broader Impacts:This research will be conducted in the biology department of a small undergraduate college in which faculty members and students participate together in research. This project will encourage undergraduates to pursue research careers by: (1) recruiting and training two students each year to conduct research; (2) developing collaborative research projects between students; (3) creating a student-led science reading group; and (4) arranging student-hosted visits by prominent scientists who will consult with students and faculty on research. A regional faculty workshop will be held on the topic of integrating research into undergraduate teaching. This study has implications for conservation management of native, heat-tolerant plants and the animals that may depend on them. It may also find application in the development of strategies to genetically engineer heat-tolerant perennial crops and ornamentals.