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，工厂使用通过光合作用产生的碳水化合物来支持其生长和发育。为了避免在不可能的光合作用的夜晚饿死，植物将白天生产的一些碳水化合物存储为夜间使用的淀粉储备。在拟南芥植物中，黎明消耗了95％的储存淀粉。有趣的是，24小时的昼夜节律控制淀粉降解的速率，因此无论夜晚的长度如何，黎明都使用适当的淀粉。尚不清楚与时钟控制的夜间淀粉使用中有关的精确分子过程。最近，自噬（自我吃）过程与夜间淀粉降解有关。 该项目将使用拟南芥植物作为模型系统研究时钟与自噬之间的关系。这些研究的结果应通过维持适当的日夜能量平衡，尤其是在环境条件的变化期间，提供提高植物生产率的策略。通过更广泛的影响，项目将培训一名研究科学家，博士后研究员和生物学本科学者计划（BUSP）的本科生。自噬是一个动态过程，在此过程中，将双膜结合的囊泡称为自噬体封闭细胞质材料，并将其靶向液泡/溶酶体以降解或回收。自噬（ATG）核心蛋白在包括拟南芥模型植物在内的真核生物中是保守的。泛素样修饰剂ATG8在自噬体生物发生，货物募集和自噬剂传递到液泡/溶酶体中起关键作用。 拟南芥ATG8相互作用研究发现了一个有趣的模块，该模块由拟南芥昼夜节律成分组成。 该项目将研究拟南芥自噬与昼夜节律时钟之间可能的分子联系。 该项目将专门研究昼夜节律时钟是否调节自噬，并且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械联系应提供有关植物中碳同化和能量稳态的见解。