Arabidopsis MAP Kinase Phosphatase 1 (AtMKP1) negatively regulates MPK6-mediated PAMP responses and resistance against bacteria
Arabidopsis MAP Kinase Phosphatase 1 (AtMKP1) negatively regulates MPK6-mediated PAMP responses and resistance against bacteria
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DOI：
10.1111/j.1365-313x.2011.04588.x
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发表时间：
2011-07-01
期刊：
影响因子：
7.2
通讯作者：
Peck, Scott C.
中科院分区：
文献类型：
--
作者：
Anderson, Jeffrey C.;Bartels, Sebastian;Peck, Scott C.
植物防御的一个主要组成部分是通过质膜定位的病原体识别受体检测病原体相关分子模式（PAMPs）。PAMP感知导致磷酸化依赖信号通路的快速和短暂激活，导致广泛的防御相关反应，包括基因表达的广泛变化。在拟南芥中，几种激酶，包括丝裂原活化蛋白激酶（MAPKs） MPK6和MPK3，在PAMP处理后迅速激活，并被认为积极调节一系列防御相关反应。相比之下，下游磷酸酶对PAMP反应的负调控仍然知之甚少。在这里，我们报告了拟南芥MAP激酶磷酸酶1 （MKP1）作为多种PAMP反应的负调节因子，包括MPK6和MPK3的激活，细胞外活性氧的瞬时产生，PAMP调节转录物亚群的积累以及幼苗生长的抑制。与在mkp1突变体中观察到的增强的PAMP应答表型一致，我们发现mkp1幼苗和成株对强毒细菌病原体丁香假单胞菌pv更具抗性。番茄（Pto） DC3000。进一步的遗传分析表明，MPK6，而不是MPK3，在mkp1幼苗中观察到的mpk1依赖性的Pto抗性增加和pamp诱导的生长抑制增强是必需的。总之，我们的数据支持MKP1作为mpk6介导的PAMP应答的负调节因子的作用。
A primary component of plant defense is the detection of pathogen-associated molecular patterns (PAMPs) by plasma membrane-localized pathogen recognition receptors. PAMP perception results in rapid and transient activation of phosphorylation-dependent signaling pathways that lead to a wide array of defense-related responses, including extensive changes in gene expression. In Arabidopsis, several kinases, including the mitogen-activated protein kinases (MAPKs) MPK6 and MPK3, are rapidly activated after PAMP treatment, and are thought to positively regulate a wide array of defense-related responses. In contrast, negative regulation of PAMP responses by downstream phosphatases remains poorly understood. Here we report the identification of Arabidopsis MAP Kinase Phosphatase 1 (MKP1) as a negative regulator of diverse PAMP responses, including activation of MPK6 and MPK3, transient production of extracellular reactive oxygen species, accumulation of a subset of PAMP-regulated transcripts, and inhibition of seedling growth. In agreement with the enhanced PAMP response phenotypes observed in the mkp1 mutant, we found that mkp1 seedlings and adult plants are more resistant to the virulent bacterial pathogen Pseudomonas syringae pv. tomato (Pto) DC3000. Further genetic analysis revealed that MPK6, but not MPK3, is required for the mkp1-dependent increase in resistance to Pto and enhanced PAMP-induced growth inhibition observed in mkp1 seedlings. Together, our data support a role for MKP1 as a negative regulator of MPK6-mediated PAMP responses.