Functions of Arabidopsis SAUR proteins

杰森·W Reed（PI），Punita Nagpal（co-PI）. 建议编号IOS-0920418：拟南芥SAUR蛋白的功能。建议活性的知识价值植物激素生长素通过很大程度上未知的机制调节植物生长和发育，包括诱导基因表达和调节细胞极性。 生长素诱导基因中最大的一类是功能未知的SAUR（小生长素上调）基因家族。 SAUR基因存在于所有开花植物中，也存在于苔藓中，因此可以执行在所有植物中保守的功能。 本研究旨在确定模式植物拟南芥中SAUR基因亚家族及其相关蛋白的功能。 初步结果表明，这些SAUR基因调节伸长的快速生长的组织，可能通过影响生长素运输或其他一些细胞生物学功能。 遗传学和生理学的方法将被用来确定所选择的SAUR基因的发育功能，它们的表达模式，以及它们是否确实影响生长素的运输。 显微镜实验将揭示SAUR蛋白的细胞内定位，以及这是否受内源性或环境信号的调节。 这些实验将确定这些SAUR蛋白存在的时间和地点，它们对生长素运输的影响，以及它们如何控制植物组织的生长。 了解生长是如何控制的，是从系统层面了解植物发育的必要前奏，其中包括来自多种不同激素和环境信号的投入。 从这些实验中获得的知识最终可能使操纵作物生长模式的实用方法成为可能。 由于SAUR基因甚至存在于brabetes中，因此该研究将与所有植物的发育相关。 在这项研究的过程中，一名博士后和一名研究生以及多名本科生将接受研究方法和具体技术的培训。

Jason W. Reed (PI), Punita Nagpal (co-PI). Proposal number IOS-0920418: Functions of Arabidopsis SAUR proteins.Intellectual merit of the proposed activityThe plant hormone auxin regulates plant growth and development by largely unknown mechanisms that include induction of gene expression and regulating cell polarity. The largest class of auxin-inducible genes are a family of SAUR (Small Auxin Up-Regulated) genes of unknown function. SAUR genes are present in all flowering plants and also in moss, and therefore may carry out a function conserved in all plants. This proposal is to determine functions of a subfamily of SAUR genes and the corresponding proteins in the model plant Arabidopsis thaliana. Preliminary results indicate that these SAUR genes regulate elongation of rapidly growing tissues, possibly by affecting auxin transport or some other cell biological function. Genetic and physiological approaches will be used to determine the developmental functions of the selected SAUR genes, their expression patterns, and whether they indeed affect auxin transport. Microscopy experiments will reveal the intracellular localization of SAUR proteins, and whether this is regulated by endogenous or environmental signals. These experiments will establish when and where these SAUR proteins are present, their effects on auxin tranport, and how they may control growth of plant tissues. Broader impact of the proposed activity Understanding how growth is controlled is a necessary prelude to developing a systems-level understanding of plant development incorporating inputs from multiple different hormonal and environmental signals. Knowledge from these experiments may ultimately enable practical approaches to manipulate growth patterns in crop plants. Since SAUR genes are present even in bryophytes, the study will be relevant to development of all plants. In the course of this research one post-doc and one graduate student as well as multiple undergraduates will be trained in research approaches and specific techniques.