拟南芥中两类内吞作用相关复合体CORVET和HOPS调控植物生殖过程的机制比较研究

内吞作用是胞外物质进入细胞的重要途径，对于物质运输和信号转导十分重要。内吞作用参与调控植物多个生长发育的过程；但到目前为止，其调控植物的生殖发育的分子机制尚不清楚。已经发表的实验结果表明，内吞过程中有两类重要的复合体CORVET和HOPS，它们各亚基成员的突变会导致植株雄配子体传递率下降，暗示这两类复合体介导的内吞作用对于植物生殖过程非常重要。这两类复合体共用四个相同的核心亚基，但又有各自不同的特有亚基。我们发现，核心亚基发生突变与特有亚基发生突变会导致不同的生殖缺陷，暗示CORVET和HOPS可能以动态组装的形式调控植物中不同的生殖过程。基于此，本研究拟从精确确定各个亚基突变体生殖表型入手，综合采用遗传学、生物化学、分子生物学以及单细胞操作等方法，鉴定出CORVET和HOPS两类复合体运输的目标蛋白货物，阐明CORVET和HOPS复合体动态组装规律以及其调控植物生殖的不同过程的分子机制。

Endocytosis represents a cellular process, in which substances, including membrane-bound receptor-signal complexes, are brought into the cell, and that is essential for material exchange and signal communication between tissues/organs/cells/subcellular compartments. This form of active transport is thought to be involved in regulation of many developmental processes in plants. However, the mechanism of this endocytosis-mediated regulation is not yet clear at the molecular level. It is well established that mutations of the subunits of either CORVET or HOPS complex, two important complexes in the endocytic pathway, would result in decrease of male transmission efficiencies in plants, suggesting that endocytic pathway is critical for plant reproduction. CORVET and HOPS share four core subunits VPS11, VPS16, VPS18 and VPS33, with two subunits VPS3 and VPS8 specific for CORVET and another two VPS39 and VPS41 specific for HOPS. In our study, mutations of either core subunits or any one of the two specific subunits resulted in different defects at different reproductive stages in Arabidopsis, suggesting that these two complexes play a distinct role in plant reproduction. Here we propose, by carefully examining the phenotypes of all the mutants of each subunits of the two complexes and in combination with genetic, biochemistry and molecular biology techniques including single cell manipulation, to identify and compare the cargo transported by the two complexes and to characterize the dynamics of the assembly and movement of the two complexes and their role in regulation of plant reproduction.