EAGER: Uncovering Mechanistic Link Between Autophagy and Circadian Clock in Arabidopsis

EAGER：揭示拟南芥自噬与昼夜节律时钟之间的机制联系

• 批准号: 1549580
• 负责人: Savithramma Dinesh-Kumar
• 金额: $ 30万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-15 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1549580&HistoricalAwards=false
• 关键词: EAGER; Uncovering; Mechanistic; Link; Between

During the daytime plants use carbohydrate generated through photosynthesis to support their growth and development. To avoid starving in the night when photosynthesis is not possible, plants store some of the carbohydrate produced in the day as starch reserve for nighttime use. In Arabidopsis plants, 95% of the stored starch is consumed by dawn. Interestingly, the 24-hour circadian clock controls the rate of starch degradation so that the appropriate amount of starch is used by dawn irrespective of the length of the night. The precise molecular processes involved in clock-controlled nighttime starch usage are not understood. Recently, the autophagy (self-eating) process has been implicated in nighttime starch degradation. This project will investigate the inter-relationship between the clock and autophagy using the Arabidopsis plant as the model system. Results from these studies should provide strategies to improve plant productivity by maintaining the appropriate day-night energy balance especially during changes in environmental conditions. Through its broader impacts, project will train a research scientist, a post-doctoral fellow, and an undergraduate student from Biology Undergraduate Scholars Program (BUSP). Autophagy is a dynamic process during which double membrane-bound vesicles called autophagosomes enclose cytoplasmic materials and target them to the vacuole/lysosome for degradation or recycling. Autophagy (Atg) core proteins are conserved among eukaryotes including Arabidopsis model plant. The ubiquitin-like modifier Atg8 plays a key role in autophagosome biogenesis, cargo recruitment, and autophagosme delivery to the vacuole/lysosome. Arabidopsis Atg8 interaction studies uncovered an intriguing module consisting of Arabidopsis circadian clock components. This project will investigate the possible molecular link between Arabidopsis autophagy and the circadian clock. The project will specifically investigate whether circadian clock regulates autophagy and whether autophagy in turn regulates clock function in Arabidopsis. Understanding the mechanistic link between autophagy and circadian system should provide insights on carbon assimilation and energy homeostasis in plants.

在白天，植物利用光合作用产生的碳水化合物来支持它们的生长和发育。为了避免在光合作用不可能的夜晚挨饿，植物储存了一些白天产生的碳水化合物作为淀粉储备供夜间使用。在拟南芥植物中，95%的储存淀粉在黎明前被消耗。有趣的是，24小时生物钟控制着淀粉降解的速度，因此无论夜晚的长度如何，黎明前都可以使用适量的淀粉。时钟控制的夜间淀粉使用所涉及的精确分子过程尚不清楚。最近，自噬（自食）过程与夜间淀粉降解有关。 本计画将以拟南芥为模式系统，探讨生物钟与自噬的相互关系。从这些研究的结果应该提供策略，以提高植物生产力，特别是在环境条件的变化保持适当的昼夜能量平衡。通过其更广泛的影响，该项目将培养一名研究科学家，一名博士后研究员和一名生物学本科生学者计划（BUSP）的本科生。自噬是一个动态的过程，在此过程中，称为自噬体的双膜结合囊泡包围细胞质物质，并将它们靶向到液泡/溶酶体进行降解或回收。自噬（Atg）核心蛋白在包括拟南芥在内的真核生物中是保守的。泛素样修饰剂Atg 8在自噬体生物发生、货物募集和自噬体递送至液泡/溶酶体中起关键作用。 拟南芥Atg 8相互作用的研究发现了一个有趣的模块组成的拟南芥昼夜节律钟组件。 本研究将探讨拟南芥自噬与生物钟之间可能的分子联系。 该项目将专门研究生物钟是否调节自噬，以及自噬是否反过来调节拟南芥中的时钟功能。了解自噬和昼夜节律系统之间的机制联系，将有助于了解植物的碳同化和能量稳态。