G protein signaling in the plant response to environmental stress

本研究旨在通过研究异源三聚体G蛋白信号转导和核RAN-GT3调节中特异性蛋白质-蛋白质相互作用来了解植物的抗逆性。 这些调控蛋白的鉴定将是理解植物抗逆性的分子基础和提高植物抗逆性的重要一步。 干旱和极端气温等气候条件的不可预测变化对农业构成了挑战性且代价高昂的风险。 植物对胁迫耐受性具有广泛的遗传变异，并且在整个农业历史中，存在在胁迫条件下提高产量的遗传选择。 需要提高植物的耐受性增强不断变化的气候条件和成功地实现改善将取决于了解这种耐受性的生物学机制。 我的实验室已经确定了大量的调控基因在面包小麦（小麦），更强烈地诱导胁迫条件下的耐受基因型比敏感基因型。我们已经确定了钙结合蛋白Clo 3和Clo 7，盐，干旱和阿坝诱导的基因Esi 2，和磷脂酶C蛋白，与两个类G蛋白，α亚基的异源三聚体蛋白复合物和RAN GT3相互作用。 由于这些G蛋白在信号传导、核输入和输出以及细胞分裂中起着核心作用，因此我们将工作重点放在这些蛋白上。我们假设这些蛋白质-蛋白质相互作用通过下调这两类G蛋白的活性来促进细胞对压力的适应。 我们已经表明，这些蛋白质在拟南芥中的同源物以相同的方式相互作用的小麦蛋白质。 我们建议使用强大的遗传工具，在拟南芥中，以推进我们的理解的基本遗传和分子机制，控制G蛋白信号，并调查这些蛋白质-蛋白质相互作用在提高植物的环境胁迫耐受性的作用。

This research proposal is directed toward understanding of stress tolerance in plants through the characterization of specific protein-protein interactions in the regulation heterotrimeric G protein signaling and the regulation of the nuclear RAN-GTPase. The characterization of these regulatory proteins will be an important step forward in understanding the molecular basis of stress tolerance and improving the tolerance of plants. Unpredictable changes in climatic conditions, including drought and extreme temperatures pose challenging and costly risks to agriculture. Plants have a wide genetic variation for stress tolerance and throughout the history of agriculture there as been genetic selection for improved yield under stress conditions. The need to improve tolerance in plants augmented by changing climatic conditions and the success in achieving improvements will be dependent on understanding the biological mechanisms underpinning this tolerance. My laboratory has identified a large number of regulatory genes in bread wheat (Triticum aestivum) that are more strongly induced by stress conditions in tolerant genotypes than in sensitive genotypes. We have identified calcium binding proteins Clo3 and Clo7, a salt, drought and ABA induced gene Esi2, and a phospholipase C proteins that interact with two classes G proteins, the alpha subunit of the heterotrimeric protein complex and the RAN GTPase. Because these classes of G proteins play central roles in signaling, nuclear import and export and in cell division we have focused our work on these proteins. We hypothesize that these protein-protein interactions contribute to the cell's adaptation to stress by down-regulating the activity of these two classes of G proteins. We have shown that the homologs of these proteins in Arabidopsis interact in the same manner as the wheat proteins. We propose to use the powerful genetic tools available in Arabidopsis to advance our understanding of the basic genetic and molecular mechanisms that control G proteins signaling and to investigate the role of these protein-protein interactions in improving environmental stress tolerance in plants.