POWRE: The Origin of the Plant Small Heat Shock Proteins

大约4.5亿年前，植物首次在陆地上定居。伴随着植物移动到陆地上的植物形式的适应已经被很好地研究了。人们对伴随着这一重要事件的生理变化或适应情况知之甚少。这个项目将集中在植物中小热休克蛋白家族的起源，以及这些小热休克蛋白的多样化是否与陆地上的运动有关的问题。所有的生物体都有热休克反应。当生物体暴露在高温下时，就会产生热休克蛋白，通过与其他蛋白质的相互作用，热休克蛋白使生物体能够抵御和生存高温应激。在陆地植物中，小的热休克蛋白是热休克反应的一个特别重要的组成部分，构成了热休克过程中产生的大部分蛋白质。与其他生物的小分子热休克蛋白相比，植物的小分子热休克蛋白也异常多样。利用cDNA克隆和聚合酶链式反应技术，PI将检测轮藻(一组藻类)和苔藓(角藻、地钱和苔藓；最古老的陆地植物谱系)的小热休克蛋白基因。等电点将确定在植物最初居住的一段时间内，小分子热休克蛋白的数量是否增加，氨基酸序列是否发生变化。这一POWRE奖项将使Waters博士能够继续她的独立研究生涯，并通过支持她作为加州大学圣地亚哥分校的访问科学家来满足家庭需求。

Plants first inhabited land approximately 450 million years ago. The adaptations in plant form that accompanied the movement of plants to land have been well studied. Much less is known about the physiological changes or adaptations that accompanied this important event. This project will focus on the origin of the small heat shock protein family in plants, and the question of whether diversification in these small heat shock proteins was associated with movement onto land. All organisms have a heat shock response. Heat shock proteins are produced when organisms are exposed to high temperatures and, through interactions with other proteins, the heat shock proteins enable organisms to withstand and survive high-temperature stress. In land plants the small heat shock proteins are a particularly important component of the heat shock response, making up the bulk of the protein produced during heat shock. Compared to the small heat shock proteins of other organisms, the plant small heat shock proteins are also unusually diverse. Using cDNA cloning and PCR techniques the PI will examine the small heat shock protein genes of Charophytes (a group of algae) and Bryophytes (hornworts, liverworts, and mosses; the most ancient lineages of land plants). The PI will determine if the small heat shock proteins increased in number and changed in amino acid sequence during the time period that plants firstinhabited land. This POWRE award will enable Dr. Waters to continue her independent research career and to attend to family needs by supporting her as a visiting scientist at the University of California, San Diego.