Ethylene is one of the key elements for cell death and Defense response control in the Arabidopsis lesion mimic mutant vad1
Ethylene is one of the key elements for cell death and Defense response control in the Arabidopsis lesion mimic mutant vad1
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DOI：
10.1104/pp.107.106302
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发表时间：
2007-10-01
期刊：
影响因子：
7.4
通讯作者：
Balague, Claudine
中科院分区：
文献类型：
--
作者：
Bouchez, Olivier;Huard, Carine;Balague, Claudine
尽管乙烯参与调节植物防御微生物攻击的信号通路的复杂串扰，但其功能仍有待阐明。病变模拟突变体vad1-1（血管相关死亡）表现出沿血管系统繁殖性超敏反应样病变的光条件外观，是研究乙烯在程序性细胞死亡和防御中的作用的良好模型。在这里，我们证明了在损伤促进条件下和植物与病原体相互作用后，vad1-1中与乙烯合成和信号传导相关的基因表达增强。对vad1-1植株与35S::ERF1转基因植株或ein2-1、ein3-1、ein4-1、ctr1-1或eto2-1突变体杂交后代的分析表明，vad1-1细胞的死亡和防御表型依赖于乙烯的生物合成和信号传导。相反，尽管ein2、ein3和ein4突变消除了vad1-1依赖性的抗性增加，但乙烯生物合成（eto2-1）或乙烯反应（35::ERF1）的正调控并未加剧这种表型。此外，VAD1在对超敏反应诱导的细菌病原体的反应中表达依赖于乙烯感知和信号传导。这些结果与先前的数据一起表明，VAD1可能作为激素信号传导的一个整合节点，乙烯与水杨酸协同作用，作为细胞死亡繁殖的积极调节剂。
Although ethylene is involved in the complex cross talk of signaling pathways regulating plant defense responses to microbial attack, its functions remain to be elucidated. The lesion mimic mutant vad1-1 (for vascular associated death), which exhibits the light-conditional appearance of propagative hypersensitive response-like lesions along the vascular system, is a good model for studying the role of ethylene in programmed cell death and defense. Here, we demonstrate that expression of genes associated with ethylene synthesis and signaling is enhanced in vad1-1 under lesion-promoting conditions and after plant-pathogen interaction. Analyses of the progeny from crosses between vad1-1 plants and either 35S::ERF1 transgenic plants or ein2-1, ein3-1, ein4-1, ctr1-1, or eto2-1 mutants revealed that the vad1-1 cell death and defense phenotypes are dependent on ethylene biosynthesis and signaling. In contrast, whereas vad1-1-dependent increased resistance was abolished by ein2, ein3, and ein4 mutations, positive regulation of ethylene biosynthesis (eto2-1) or ethylene responses (35::ERF1) did not exacerbate this phenotype. In addition, VAD1 expression in response to a hypersensitive response-inducing bacterial pathogen is dependent on ethylene perception and signaling. These results, together with previous data, suggest that VAD1 could act as an integrative node in hormonal signaling, with ethylene acting in concert with salicylic acid as a positive regulator of cell death propagation.