Molecular Genetic Analysis of Cell Polarity in the Maize Leaf Epidermis

玉米叶表皮细胞极性的分子遗传学分析

• 批准号: 0212724
• 负责人: Laurie Smith
• 金额: $ 39万
• 依托单位: University of California-San Diego
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0212724&HistoricalAwards=false
• 关键词: Molecular; Genetic; Analysis; Cell; Polarity

0212724SmithAs in all other eukaryotes and prokaryotes, diversification of form and function during plant development depends on cell polarity. Relatively little is known in molecular terms about how cells translate polarizing cues into localized cytoskeletal assemblies that direct the polarization of other cell components or of the cell growth machinery. With the support of a prior NSF award, a genetic approach was taken to analyze mechanisms by which maize leaf epidermal cells become polarized, focusing on three Brick (Brk) genes required for the polarized growth and division of epidermal cells. Building on this work, studies are proposed here to further advance our understanding of plant cell polarity, with the following specific objectives: 1. Complementary approaches will be taken to localize BRK1 protein in polarizing subsidiary mother cells and expanding epidermal pavement cells. 2. Complementary approaches will be taken to identify candidate BRK1-interacting proteins and investigate their in vivo interactions with BRK1. 3. As shown for the Brk genes, two Pangloss (Pan) genes promote the polarization of subsidiary mother cells, but are not required for polarized cell expansion. The functions of Pan genes and how they relate to those of Brk genes will be further elucidated through phenotypic analysis of single and double mutants. 4. To help build a bigger picture of how maize leaf epidermal cells become polarized, one additional epidermal cell polarity gene (Pan1, Brk2, or Brk3) will be cloned and molecularly characterized by means of transposon tagging. The intellectual merit of the work proposed is augmented by the central importance of cell polarity in the development of all eukaryotes and prokaryotes, and the fact that BRK1 (and probably the entire pathway in which all 3 Brk genes were shown to function) is conserved among eukaryotes. Therefore, our findings will most likely have an impact outside the boundaries of plant cell biology. The broader impact of the work proposed will mainly be the education and training of young scientists participating in the research, including one postdoc, one Ph.D. student, and a series of undergraduates.

0212724Smith与所有其他真核生物和原核生物一样，植物发育过程中形式和功能的多样化取决于细胞的极性。在分子方面，细胞如何将极化信号转化为局部的细胞骨架组件，指导其他细胞组件或细胞生长机制的极化，人们知之甚少。在先前NSF奖的支持下，采用遗传学方法分析了玉米叶片表皮细胞极化的机制，重点研究了表皮细胞极化生长和分裂所需的三个Brick(BRK)基因。在这项工作的基础上，提出了进一步加深对植物细胞极性的理解的研究，具体目标如下：1.将采取补充的方法在极化的辅助母细胞和扩张的表皮铺面细胞中定位BRK1蛋白。2.将采取互补的方法来确定候选的BRK1相互作用蛋白，并研究它们在体内与BRK1的相互作用。3.如BRK基因所示，两个Panglos(PAN)基因促进辅助母细胞的极化，但不是极化细胞扩张所必需的。通过对单突变体和双突变体的表型分析，将进一步阐明PAN基因的功能及其与BRK基因的关系。4.为了更好地了解玉米叶片表皮细胞如何极化，将克隆一个额外的表皮细胞极性基因(Pan1、brk2或brk3)，并通过转座子标记的方法对其进行分子鉴定。细胞极性在所有真核生物和原核生物发育中的核心重要性，以及BRK1(可能是所有3个BRK基因的功能被证明的整个途径)在真核生物中是保守的，这一事实增强了所提出的工作的智力价值。因此，我们的发现很可能会在植物细胞生物学的边界之外产生影响。拟议工作的更广泛影响将主要是对参与研究的年轻科学家进行教育和培训，其中包括一名博士后、一名博士后和一系列本科生。