RUI: Role of Rubisco Activase Gene Regulation in Acclimation of Photosynthesis to Heat Stress

在农业和自然环境中，光合作用的高温抑制被认为是植物生长和生产力的主要限制因素。随着全球气温预计将上升，旨在了解和减少植物对热胁迫的敏感性的研究可能会对未来的作物产量产生重大影响。在植物碳同化的限速阶段，热胁迫似乎主要通过削弱Rubisco的活性来抑制光合作用。Rubisco依靠一种名为激活酶的酶来维持其功能潜力。在热胁迫期间，激活酶失去维持Rubisco活性的能力，导致光合作用和植物生长速度下降。有大量证据表明，光合作用可以适应长期的热胁迫，而激活酶可能在适应反应中发挥核心作用。然而，光合作用热适应的基础在很大程度上是不确定的。目前的项目建立在支持激活酶基因调控参与适应反应的最近工作的基础上。本研究的重点是解决高温下植物中激活酶基因表达和蛋白质调控的具体问题，并开始确定这些调控过程在光合作用适应高温胁迫中的作用。具体地说，该项目提出了热应激过程中激活酶的调节受其3‘-非翻译区的遗传因素影响的假说，并试图用一种独特的方法来评估活化酶蛋白在体内的周转特性。了解在热应激过程中支持激活酶基因和蛋白表达的调控过程将极大地促进设计有效的策略来促进植物，包括重要的作物光合作用的耐热胁迫。该项目将在格林内尔学院与一群不同的本科生密切合作进行，这些学生将在各级参与收集、分析和交流研究结果。通过在以探究技能为中心的生物课程中提供独立的研究机会，该项目将保持该机构已证实的将科学研究整合到广泛和相应的文科教育中的传统。

High temperature inhibition of photosynthesis is recognized as a primary limitation to the growth and productivity of plants in both agricultural and natural environments. With global temperatures predicted to rise, research aimed at understanding and reducing plant susceptibility to heat stress is likely to have a significant impact on future crop yields. Heat stress appears to inhibit photosynthesis primarily by impairing the activity of Rubisco during the rate-limiting step of carbon assimilation in plants. Rubisco relies on an enzyme called activase to maintain its functional potential. During periods of heat stress, activase loses its ability to sustain Rubisco activity, resulting in decreased rates of photosynthesis and plant growth. There is substantial evidence that photosynthesis can acclimate to long term heat stress and that activase may play a central role in the acclimatory response. However, the basis for heat acclimation of photosynthesis is largely undefined. The current project builds on recent work supporting the involvement of activase gene regulation in the acclimation response. The focus of this research is to address specific questions regarding activase gene expression and protein regulation in plants exposed to elevated temperatures, and to begin to define the role of these regulatory processes in acclimation of photosynthesis to heat stress. Specifically, the project addresses the hypothesis that activase regulation during heat stress is influenced by genetic elements in its 3'-untranslated region, and seeks to evaluate activase protein turnover properties in vivo using a unique approach.Knowledge of the regulatory processes that support activase gene and protein expression during heat stress will greatly facilitate the design of effective strategies to promote heat stress tolerance of photosynthesis in plants, including important crop species. This project will be carried out at Grinnell College in close partnership with a diverse group of undergraduate research students who will participate at all levels in the gathering, analysis and communication of the results of the study. By providing independent research opportunities within a biology curriculum centered on inquiry-based skills, this project will maintain the institution's proven tradition of integrating scientific research into a broad and consequential liberal arts education.