The Exocyst and Vesicle Trafficking In Plant Development

PI：John E. FowlerNSF提案# IOS-0920747：“植物发育中的外囊和囊泡运输“在每个植物细胞内，微小的膜结合囊泡携带植物生长和发育所必需的各种物质到质膜，这有助于形成细胞？的边界。 这些囊泡在精确的正确时间被递送到质膜上的正确位置的机制还没有被很好地理解，尽管这种严格的调节对于诸如细胞分裂、细胞壁伸长、防御病原体和细胞间通讯（例如，植物激素信号）。 这个项目将研究一个特殊的八种蛋白质的复合物，外囊，在这种囊泡运输的作用。 基于在酵母和哺乳动物系统中的工作，假设外囊作为囊泡与其在质膜上的预期位置之间的系链起作用，有助于在发育适当的时间将囊泡靶向特定位点。 外孢囊在植物中的重要性通过外孢囊蛋白的突变来证明，外孢囊蛋白的突变导致有缺陷的花粉管生长、在黑暗中减少的茎伸长和侏儒症（包括短根）。 该项目将利用遗传学，生物化学和细胞生物学方法，更具体地调查外囊？的可能的作用，在囊泡运输，植物激素信号，和胞质分裂（细胞分裂），并将检查两个花粉管伸长和主根生长的模式植物，拟南芥。 这项工作可能会通过为旨在改变植物生长、细胞壁（例如，用于生物燃料）或农作物中的病原体反应。 该项目将培训一名博士后研究人员和一名研究生，促进与捷克共和国研究人员的富有成效的合作，并向当地小学和高中学生提供科学宣传。

PI: John E. FowlerNSF Proposal # IOS-0920747: "The Exocyst and Vesicle Trafficking In Plant Development"Inside each plant cell, tiny membrane-bound vesicles carry a variety of materials essential for plant growth and development to the plasma membrane, which helps form the cell?s boundary. The mechanism by which these vesicles are delivered to the correct location on the plasma membrane at precisely the right time is not well understood, even though this tight regulation is fundamental to such processes as cell division, cell wall elongation, defense against pathogens, and intercellular communication (e.g., plant hormone signaling). This project will study the role of a particular complex of eight proteins, the exocyst, in such vesicle trafficking. Based upon work in yeast and mammalian systems, the exocyst is hypothesized to work as a tether between a vesicle and its intended location at the plasma membrane, helping to target vesicles to specific sites at developmentally appropriate times. The importance of the exocyst in plants is demonstrated by mutations in exocyst proteins, which cause defective pollen tube growth, reduced stem elongation in the dark, and dwarfism (including short roots). This project will utilize genetic, biochemical, and cell biological methods to more specifically investigate the exocyst?s possible roles in vesicle trafficking, phytohormone signaling, and cytokinesis (cell division), and will examine both pollen tube elongation and primary root growth in the model plant, Arabidopsis thaliana. This work is likely to have broader impacts by informing applied work that seeks to modify plant growth, cell walls (e.g., for biofuels), or pathogen response in agricultural crops. This project will train a postdoctoral researcher and a graduate student, foster a productive collaboration with researchers in the Czech Republic, and provide science outreach to local elementary and high school students.