Signal Transduction Pathways of the Plant Oxidative Burst

9725934 Low，Philip S. 氧化猝发是植物抗病性的重要早期防御机制。 爆发反应的特征在于在病原体或病原体产生的激发子分子刺激植物细胞后几分钟内快速合成高活性氧化合物（超氧化物或过氧化氢）。 由于这种氧爆发在整个植物界都有发现，并且由于它可能是几种植物防御机制的关键组成部分，因此其详细的表征具有相当大的重要性和兴趣。 这个项目的总体目标是阐明信号转导途径，激活时，激发子结合到细胞表面或细胞质受体，并达到高潮时，氧化酶复合物组装和激活，产生活性氧的爆发。 具体目的是（a）表征启动对寡聚半乳糖醛酸的应答的特异性激发子活化的蛋白激酶，（B）确定可能的中间组分（G-蛋白、Ca++、磷脂酶C、其他蛋白激酶）的活化时间，所述中间组分将所得信号传递给氧化酶以活化它，以及（c）克隆激酶和几种氧化酶亚基的基因。 这些目标的完成将大大提高我们的理解，导致氧化爆发的特定信号转导过程，并将提供见解的一般原则，在植物细胞中的信号转导策略。 这项工作的一个实际延伸是，如果氧化爆发可以被设计成对更快或更广泛的病原体做出反应，那么农业中对有毒农药的依赖就可以减少。

9725934 Low, Philip S. The oxidative burst constitutes an important early defense mechanism linked to disease resistance in plants. The burst response is characterized by the rapid synthesis of highly reactive oxygen compounds (superoxide or hydrogen peroxide) within minutes after stimulation of the plant cell by pathogens or pathogen-generated elicitor molecules. Because this oxygen burst is found throughout the plant kingdom, and since it may be a critical component of several plant defense mechanisms, its detailed characterization is of considerable importance and interest. The overall goal of this project is to elucidate the signal transduction pathway that is activated when an elicitor binds to a cell surface or cytoplasmic receptor and which culminates when the oxidase enzyme complex is assembled and activated to produce the burst of reactive oxygen. The specific aims are (a) to characterize a specific elicitor-activated protein kinase that initiates the response to oligogalacturonic acid, (b) to determine the timing of activation of possible intermediate components (G-proteins, Ca++, phospholipase C, other protein kinases) that relay the resulting signal to the oxidase to activate it, and (c) to clone the genes for both the kinase and several of the oxidase subunits. Completion of these objectives will greatly enhance our understanding of the specific signal transduction processes that lead to the oxidative burst and will provide insights into general principles of signal transduction strategies in plant cells. One practical extension of this work is that if the oxidative burst can be engineered to respond more rapidly or to a wider range of pathogens, reliance on toxic pesticides in agriculture could be reduced.