Negative regulation of defense responses in plants by a conserved MAPKK kinase
Negative regulation of defense responses in plants by a conserved MAPKK kinase
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DOI：
10.1073/pnas.011405198
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发表时间：
2001-01-02
影响因子：
11.1
通讯作者：
Innes, RW
中科院分区：
文献类型：
--
作者：
Frye, CA;Tang, DZ;Innes, RW
拟南芥的增强抗病性1（edr 1）突变赋予对由真菌白粉病菌引起的白粉病的抗性。edr1突变介导的抗性与诱导几种防御反应相关，包括宿主细胞死亡。双突变体分析表明，所有edr1相关的表型被抑制的突变，阻断水杨酸（SA）的感知（nim 1）或减少SA的生产（pad4和eds1）。NahG转基因，降低内源性SA水平，也抑制edr1。相反，ein2突变并没有抑制edr1介导的抗性和相关的表型，表明乙烯和茉莉酸诱导的反应不是edr1抗性所必需的。EDR1基因是通过定位克隆的方法分离出来的，并且被发现编码一个与CTR1类似的MAP激酶，CTR1是拟南芥中乙烯反应的负调节因子。综上所述，这些数据表明EDR1在MAP激酶级联的顶部起作用，该级联负调节SA诱导的防御反应。推测EDR1的直系同源物存在于单子叶植物如水稻和大麦中，表明EDR1可以调节广泛的作物物种中的防御反应。
The enhanced disease resistance 1 (edr1) mutation of Arabidopsis confers resistance to powdery mildew disease caused by the fungus Erysiphe cichoracearum. Resistance mediated by the edr1 mutation is correlated with induction of several defense responses, including host cell death. Double mutant analysis revealed that all edr1-associated phenotypes are suppressed by mutations that block salicylic acid (SA) perception (nim 1) or reduce SA production (pad4 and eds1). The NahG transgene, which lowers endogenous SA levels, also suppressed edr1. In contrast, the ein2 mutation did not suppress edr1-mediated resistance and associated phenotypes, indicating that ethylene and jasmonic acid-induced responses are not required for edr1 resistance. The EDR1 gene was isolated by positional cloning and was found to encode a putative MAP kinase kinase kinase similar to CTR1, a negative regulator of ethylene responses in Arabidopsis, Taken together, these data suggest that EDR1 functions at the top of a MAP kinase cascade that negatively regulates SA-inducible defense responses. Putative orthologs of EDR1 are present in monocots such as rice and barley, indicating that EDR1 may regulate defense responses in a wide range of crop species.