The cytosolic thiol peroxidase PRXIIB is an intracellular sensor for H2O2 that regulates plant immunity through a redox relay
The cytosolic thiol peroxidase PRXIIB is an intracellular sensor for H2O2 that regulates plant immunity through a redox relay
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胞质硫醇过氧化物酶 PRXIIB 是一种细胞内 H2O2 传感器，通过氧化还原继电器调节植物免疫力
DOI：
10.1038/s41477-022-01252-5
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发表时间：
2022-10-01
期刊：
影响因子：
18
通讯作者：
Zhou, Jian-Min
中科院分区：
文献类型：
--
作者：
Bi, Guozhi;Hu, Man;Zhou, Jian-Min
H2O2 的快速产生是植物对多种病原体反应的标志，并且在感知免疫原性模式的各种受体下游信号传导中发挥着至关重要的作用。然而，植物感知 H2O2 来调节免疫力的机制仍知之甚少。我们发现，免疫激活时产生的内源性 H2O2 可被硫醇过氧化物酶 PRXIIB 通过 Cys51 氧化来感知，这对于针对丁香假单胞菌的气孔免疫至关重要。我们进一步表明，在免疫刺激的细胞中，PRXIIB 通过 Cys51 与 2C 型蛋白磷酸酶 ABA 不敏感 2 (ABI2) 结合，随后将 H2O2 信号转导至 ABI2。这种氧化作用在体外使 H2O2 介导的 ABI2 磷酸酶活性抑制显着敏感，并且是植物气孔免疫所必需的。总之，我们的结果说明了氧化还原继电器，其中 PRXIIB 作为 H2O2 传感器，ABI2 作为目标蛋白，在植物免疫过程中介导活性氧信号传导。
Rapid production of H2O2is a hallmark of plant responses to diverse pathogens and plays a crucial role in signalling downstream of various receptors that perceive immunogenic patterns. However, mechanisms by which plants sense H2O2to regulate immunity remain poorly understood. We show that endogenous H2O2generated upon immune activation is sensed by the thiol peroxidase PRXIIB via oxidation at Cys51, and this is essential for stomatal immunity against Pseudomonas syringae. We further show that in immune-stimulated cells, PRXIIB conjugates via Cys51 with the type 2C protein phosphatase ABA insensitive 2 (ABI2), subsequently transducing H2O2signal to ABI2. This oxidation dramatically sensitizes H2O2-mediated inhibition of the ABI2 phosphatase activity in vitro and is required for stomatal immunity in plants. Together, our results illustrate a redox relay, with PRXIIB as a sensor for H2O2and ABI2 as a target protein, that mediates reactive oxygen species signalling during plant immunity.