Functional Interplay Between Arabidopsis NADPH Oxidases and Heterotrimeric G Protein
Functional Interplay Between Arabidopsis NADPH Oxidases and Heterotrimeric G Protein
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DOI：
10.1094/mpmi-10-12-0236-r
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发表时间：
2013-06-01
影响因子：
3.5
通讯作者：
Dangl, Jeffery L.
中科院分区：
文献类型：
--
作者：
Angel Torres, Miguel;Morales, Jorge;Dangl, Jeffery L.
植物NADPH氧化酶产生活性氧（ROS）响应病原体，在不同的细胞环境中具有不同的功能。不同的表型结果可能来自NADPH氧化酶依赖性ROS与介导防御激活的其他信号组分的相互作用。我们分析了NADPH氧化酶AtRbohD和AtRbohF和拟南芥异源三聚体G蛋白之间的相互作用。异源三聚体G蛋白的G β亚基（AGBI）是对不同假单胞菌菌株的完全抗病性所必需的。遗传学研究表明，在P. erichingae感染后，AGBI和AtRbohD和AtRbohF可以在相同的途径中起作用，因为agb 1无效等位基因对NADPH氧化酶无效等位基因是上位性的，组合突变体显示agb 1表型，并且agb 1抑制一些atrbohD atrbohF双突变体表型。相比之下，增加的敏感性，显示由agbl和atrbohD atrbohF的necrotrophic真菌黄瓜炭疽病菌是在agbl atrbohD atrbohF三重突变体增强，这表明NADPH氧化酶和异源三聚体G蛋白介导不同的响应途径，响应于这种necrotrophic病原体。由AGBI介导的防御反应是独立的病原体依赖的水杨酸积累和信号传导，因为agb1_2（isochorisnzate synthase 2）双突变体与两个单突变体相比显示出增强的对黄瓜疫霉和黄瓜斑点落叶病菌的疾病易感性。这项研究阐明了介导防御激活的信号事件之间的复杂相互作用，这取决于植物-病原体相互作用的类型。
The plant NADPH oxidases produce reactive oxygen species (ROS) in response to pathogens that have diverse functions in different cellular contexts. Distinct phenotypic outcomes may derive from the interaction of NADPH oxidase-dependent ROS with other signaling components that mediate defense activation. We analyze the interaction between NADPH oxidases AtRbohD and AtRbohF and the Arabidopsis heterotrimeric G protein. The G beta subunit (AGBI) of the heterotrimeric G protein is required for full disease resistance to different Pseudomonas syringae strains. Genetic studies reveal that, upon P. syringae infection, AGBI and AtRbohD and AtRbohF can function in the same pathway, as the agb1 null allele is epistatic to the NADPH oxidase null alleles, combinatorial mutants display the agb1 phenotypes, and agb1 suppresses some of the atrbohD atrbohF double mutant phenotypes. In contrast, increased susceptibility to the necrotrophic fungus Plectosphaerella cucumerina displayed by agbl and atrbohD atrbohF is enhanced in the agbl atrbohD atrbohF triple mutant, suggesting that NADPH oxidase and heterotrimeric G proteins mediate different response pathways in response to this necrotrophic pathogen. The defense response mediated by AGBI is independent of pathogen-dependent salicylic acid accumulation and signaling, as the agb1 sid2 (isochorisnzate synthase 2) double mutant showed enhanced disease susceptibility to P. syringae and Plectosphaerella cucumerina as compared with both single mutants. This study exemplifies the complex interplay between signaling events mediating defense activation, depending on the type of plant-pathogen interaction.