Involvement of Salicylic Acid Inhibition of Catalase and Ascorbate Peroxidase in Plant Defense Responses

摘要9514239 Klessig 水杨酸（SA）在植物抗微生物攻击的防御反应中起着重要的作用。 本实验室已经鉴定了一种SA结合蛋白，它是一种过氧化氢酶，其活性被SA阻断。 有待检验的假设是，H2O2和其他活性氧物质水平的增加诱导植物抗性（PR）基因（PR . 本实验研究了SA对过氧化氢酶和抗坏血酸过氧化物酶（另一种H2O2降解酶）的抑制作用以及对PR基因抗性基因的诱导作用。 将在感染部位测定SA、H2O2和PR mRNA水平的时程。 通过引入nahG基因（其编码分解水杨酸的酶）制成的转基因植物将被检查并以多种方式与野生型植物进行比较。 还将检查通过引入这些酶的反义而制备的具有抑制水平的过氧化氢酶或抗坏血酸过氧化物酶的转基因植物。 这些实验将提供关于水杨酸如何在植物防御反应中起作用的信息。 ***

Abstract 9514239 Klessig Salicylic acid (SA) has been found to play an important role in the activation of defense responses against microbial attack in plants. This laboratory has identified a SA binding protein, which is a catalase, and its activity is blocked by SA. The hypothesis to be tested is that increased levels of H2O2 and other reactive oxygen species induce plant resistance (PR) genes (PR . In this proposal experiments will be done to study the role of catalase and ascorbate peroxidase (another H202 degrading enzyme) inhibition by SA, as well as he induction of PR gene resistant genes. The time course of the levels of SA, H2O2 and PR mRNA will be determined at the sites of infection. Plants made transgenic by the introduction of the nahG gene, which codes for the enzyme that breaks down salicylic acid will be examined and compared in a number of way to the wild type plants. Transgenic plants with suppressed levels of catalase or ascorbate peroxidase, made by introducing antisense to these enzymes will also be examined. These experiments will provide information on how salicyclic acids acts in the plant defense response. ***