Characterization of the Salicylic Acid Signal Transduction Pathway in Plant Defense Responses

Klessig 9723952鉴定植物防御反应中的水杨酸信号转导途径越来越多的证据表明，水杨酸(SA)是激活和/或增强局部和系统抗性防御反应所需的重要内源信号。本研究将继续对SA信号转导通路(S)的组成成分进行鉴定、克隆和鉴定，该通路可导致防御反应的激活，特别是病程相关(PR)基因的表达。将继续追求两个主要目标：i)鉴定SA信号转导改变的拟南芥突变体；ii)鉴定可能参与SA反应的PR-2d启动子结合蛋白。遗传、分子和生化方法的组合正被用于拟南芥和烟草(烟草)。遗传方法包括分离和鉴定拟南芥突变体，构建转基因拟南芥和烟草植株以鉴定和鉴定SA/防御信号通路的顺式和反式作用成分(S)。分子方法包括克隆、DNA测序、Southern、Northern和Western blotting、酵母单杂交和双杂交筛选、定点突变和重组蛋白的生产。蛋白质提纯、酶分析和蛋白质-DNA或蛋白质-蛋白质相互作用的表征代表了一些生化工具，这些工具正被用来进一步表征潜在的途径成分。病毒(烟草花叶病毒TMV和萝卜皱缩病毒TCV)和细菌(番茄假单胞菌、黄斑病或烟粉虱)都被用来激活防御途径(S)并研究其成分。抗病和感病植物之间的一个关键区别是对入侵病原菌的及时识别和对寄主防御的快速有效激活。因此，研究枯萎植物抗病的主要目的之一是鉴定和鉴定植物成分，这些成分在导致这些寄主防御系统激活的信号转导过程中起着关键作用。鉴定和鉴定这些成分对于我们理解抗病机制是至关重要的。此外，通过遗传和分子方法操纵它们提供了增强植物抗病能力的令人兴奋的前景。

Klessig 9723952 Characterization of the Salicylic Acid Signal Transduction Pathway in Plant Defense Responses An ever increasing body of evidence indicates that salicylic acid (SA) is an important endogenous signal required for activation and/or potentiation of defense responses in both local and systemic resistance. This research will continue studies to identify, clone, and characterize the components of the SA signal transduction pathway(s) which lead to activation of defense responses, in particular pathogenesis-related (PR) gene expression. Two major objectives will continue to be pursued: i) characterization of Arabidopsis mutants with altered SA signal transduction and ii) characterization of PR-2d promoter binding proteins potentially involved in SA responsiveness. A combination of genetic, molecular, and biochemical approaches are being utilized in Arabidopsis and Nicotiana tabacum (tobacco). Genetic approaches include isolation and characterization of Arabidopsis mutants and construction of transgenic Arabidopsis and tobacco plants to identify and characterize cis- and trans-acting components of the SA/defense signaling pathway(s). Molecular approaches include cloning, DNA sequencing, Southern, northern, and western blotting, yeast one- and two-hybrid screening, site-directed mutagenesis, and production of recombinant proteins. Protein purification, enzyme analysis, and characterization of protein-DNA or protein-protein interactions represent some of' the biochemical tools that are being used to further characterize potential pathway components. Both viral (tobacco mosaic virus TMV and turnip crinkle virus TCV ) and bacterial (Pseudomonas syringae pv tomato, maculicola, or tabaci) pathogens are being used to activate the defense pathway(s) and study its components. A key difference between resistant and susceptible plants is the timely recognition of the invading pathogen and the rapid and effective activation of host defenses. Thus, one of the major aims of stu dying plant disease resistance is to identify and characterize plant components which are crucial for the signal transduction processes leading to activation of these host defenses. Identification and characterization of these components are essential to our understanding of the mechanisms of disease resistance. Furthermore, their manipulation through genetic and molecular approaches offers the exciting prospect of enhancing plant disease resistance.