Functional Characterization of the Arabidopsis Thaliana ARG1 Gene Involved in Gravity Signal Transduction

威斯康星大学麦迪逊分校（University of Wisconsin-Madison）的帕特里克·h·马森（Patrick H. Masson）博士获得了一笔拨款，用于表征与向地性有关的蛋白质。向地性是一种生理过程，使植物器官能够利用重力作为生长指南。在大多数植物中，向地性决定了地上的枝条向上生长，根部向下生长到土壤中。它使芽接触到阳光，使根吸收水分和矿物质离子。不幸的是，我们对这种复杂生理反应的分子机制知之甚少。马森博士的研究小组已经确定并描述了模式植物拟南芥（Arabidopsis thaliana）的向地性所必需的一组蛋白质。这些蛋白在结构上与所有生物体中发现的伴侣蛋白亚群相关，这些蛋白涉及特定细胞和发育过程中蛋白质复合物的折叠、运输和组装，以及对环境刺激的反应。利用分子遗传学和生化程序，马森的研究小组将表征受这些伴侣影响的蛋白质，并确定它们在重力信号转导中的作用。这些研究将增强我们对特定分子伴侣调节植物重力信号转导的分子机制的理解。反过来，这些信息可能会对我们理解这些分子在其他系统（如哺乳动物）中所起的作用产生深远的影响。从长远来看，该项目还可能产生重要的农业应用。事实上，倾斜现象对农业生产有重要影响。例如，由于风或暴雨（倒伏）导致植物枯萎，农业每年都会遭受巨大的生产损失。从长远来看，更好地理解控制向地性的分子机制，可能会为改善旨在减少倒伏的农业实践或设计更好地抵抗风雨的植物提供所需的信息和工具。最后，这个项目将有一个重要的教育组成部分，因为它将涉及到博士后的培训，由研究生，本科生和高中生协助。

A grant has been awarded to Dr. Patrick H. Masson of the University of Wisconsin-Madison, to characterize proteins involved in gravitropism, a physiological process that allows plant organs to use gravity as a growth guide. In most plants, gravitropism dictates upward shoot growth above ground, and downward root growth into the soil. It allows shoots to reach light, and roots to take up water and mineral ions. Unfortunately, very little is known about the molecular mechanisms underlying this complex physiological response. Dr. Masson's group has identified and characterized a group of proteins that are essential for gravitropism in the model plant Arabidopsis thaliana. These proteins are structurally related to a subgroup of chaperone proteins found in all organisms, which have been implicated in the folding, trafficking and assembly of protein complexes involved in specific cellular and developmental processes, as well as in responses to environmental stimuli. Using molecular genetic and biochemical procedures, Masson's research team will characterize proteins that are affected by these chaperones, and define their roles in gravity signal transduction.These studies will enhance our understanding of the molecular mechanisms that allow specific molecular chaperones to modulate gravity signal transduction in plants. In turn, this information may have profound implications for our understanding of the role played by such molecules in other systems, such as mammals. This project may also result in important agricultural applications in the long term. Indeed, gravitropism has important consequences for agricultural productions. For instance, agriculture encounters large production losses every year, due to plant prostration by wind or heavy rains (lodging). A better understanding of the molecular mechanisms that govern gravitropism may, in the long term, provide the information and tools needed to improve agricultural practices aimed at reducing lodging, or engineer plants that better resist to wind and rain. Finally, this project will have an important educational component to it, as it will involve the training of a postdoctoral fellow, assisted by graduate, undergraduate and high school students.