Nirmala Jayaveeramuthu, Dahl Stephanie, Steffenson Brian J, Kannangara C Gamini, von Wettstein Diter, Chen Xianming, Kleinhofs Andris
Department of Crop and Soil Sciences, U.S. Department of Agriculture-Agricultural Research Service, Washington State University, Pullman, WA 99164, USA.
Proc Natl Acad Sci U S A. 2007 Jun 12;104(24):10276-81. doi: 10.1073/pnas.0703758104. Epub 2007 Jun 4.
In plants, disease resistance mediated by the gene-for-gene mechanism involves the recognition of specific effector molecules produced by the pathogen either directly or indirectly by the resistance-gene products. This recognition triggers a series of signals, thereby serving as a molecular switch in regulating defense mechanisms by the plants. To understand the mechanism of action of the barley stem rust resistance gene Rpg1, we investigated the fate of the RPG1 protein in response to infection with the stem rust fungus, Puccinia graminis f. sp. tritici. The investigations revealed that RPG1 disappears to undetectable limits only in the infected tissues in response to avirulent, but not virulent pathotypes. The RPG1 protein disappearance is rapid and appears to be due to specific protein degradation via the proteasome-mediated pathway as indicated by inhibition with the proteasomal inhibitor MG132, but not by other protease inhibitors.
在植物中，由基因对基因机制介导的抗病性涉及由抗病基因产物直接或间接识别病原体产生的特定效应分子。这种识别触发一系列信号，从而作为调节植物防御机制的分子开关。为了了解大麦秆锈病抗性基因Rpg1的作用机制，我们研究了RPG1蛋白在受到秆锈菌（Puccinia graminis f. sp. tritici）感染时的命运。研究表明，RPG1仅在感染无毒力而非毒力致病型的组织中消失至检测不到的水平。RPG1蛋白的消失很快，似乎是由于蛋白酶体介导的途径导致的特定蛋白质降解，蛋白酶体抑制剂MG132的抑制作用表明了这一点，而其他蛋白酶抑制剂则没有这种作用。
