拟南芥TOR复合体调控微丝骨架动态的分子机制

微丝广泛存在于真核细胞中，通过高度的动态变化参与囊泡运输、细胞器运动和胞吞胞吐等基本生理过程。植物细胞的周质微丝能在上游信号作用下迅速发生结构重排，通过改变自身结构和分布来调节其参与的生理过程，在植物细胞快速响应外界刺激过程中发挥重要作用。目前关于植物细胞中上游信号如何传递至微丝骨架这一重要科学问题的研究非常有限。在前期工作中，申请人通过遗传学手段筛选到拟南芥TOR复合体成员Raptor1B的突变体具有耐受微丝解聚药物处理的表型，并初步确定了TOR复合体-液泡ATP酶-微丝骨架的信号通路。在本项目中，申请人拟综合利用细胞生物学和生物化学等技术手段对这条通路的信号传递机制展开深入研究，解析拟南芥TOR复合体调控微丝骨架动态的分子机理，并探索该通路在植物细胞微丝响应生长素和葡萄糖等上游信号中的作用。该项目的开展对于认知植物细胞如何感知和响应植物生长和发育过程中的环境变化具有重要的科学价值。

Actin cytoskeleton is widely expressed in eukaryotic cells, where it is highly dynamic and participates in a multitude of fundamental physiological processes, including vesicle transportation, organelle movement, endocytosis and exocytosis. In response to upstream signals, plant cells quickly rearrange the organization of their cortical actin filaments. This will consequently lead to the adjustment of the relevant physiological processes that actin cytoskeleton is involved in. Thus, the dynamics of actin cytoskeleton is of cardinal importance for the proper response to external stimuli in plant cells. However, so far little has been known about the signaling pathways regulating actin dynamics in plant cells. Based on a forward genetic screening we had preliminarily established a novel signaling pathway controlling actin dynamics in Arabidopsis: TOR complex – Vacuolar ATPase – actin filaments. In this proposal we aim to uncover the detailed mechanism underlying the signaling pathway by combination of cell biology, biochemistry and other techniques. We will also investigate whether and how this signaling pathway regulates the instant response of cortical actin filaments to upstream signals, such as auxin and glucose, in plant cells. The project will shed light on understanding how plant cells perceive and respond to environmental changes during plant growth and development.