Erwinia amylovora type three-secreted proteins trigger cell death and defense responses in Arabidopsis thaliana
Erwinia amylovora type three-secreted proteins trigger cell death and defense responses in Arabidopsis thaliana
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DOI：
10.1094/mpmi-21-8-1076
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发表时间：
2008-08-01
影响因子：
3.5
通讯作者：
Barny, M. -A.
中科院分区：
文献类型：
--
作者：
Degrave, A.;Fagard, M.;Barny, M. -A.
解淀粉欧文氏菌是引起火疫病的细菌，火疫病是一种影响蔷薇科植物的坏死性疾病。E.食淀粉菌的致病性需要功能性第三型分泌系统（T3 SS）。我们在这里表明，E。amylovora引发拟南芥T3 SS依赖性细胞死亡。植物通过诱导T3 SS依赖性防御反应来响应，包括水杨酸（SA）非依赖性胼胝质沉积、SA防御途径的激活、活性氧（ROS）积累和茉莉酸/乙烯防御途径的一部分。这些反应中有几种与在寄主植物中观察到的反应相似。我们发现E. amylovora在A.不能简单地用抗性基因产物RPS 2识别AvrRpt 2（ea）来解释拟南芥的耐药性。然后，我们分析了三型分泌蛋白（T3 SPs）DspA/E，HrpN和HrpW在诱导细胞死亡和防御反应中的作用。thaliana感染相应的E.食淀粉菌突变株。发现HrpN和DspA/E在诱导细胞死亡、激活防御途径和ROS积累中起重要作用。测试的T3 SP中没有一个在诱导SA独立的胼胝质沉积中起主要作用。T3 SPs在A. thaliana与它们在寄主植物上的相对重要性相关，表明A.可将拟南芥作为研究其作用的模式。
Erwinia amylovora is the bacterium responsible for fire blight, a necrotic disease affecting plants of the rosaceous family. E. amylovora pathogenicity requires a functional type three secretion system (T3SS). We show here that E. amylovora triggers a T3SS-dependent cell death on Arabidopsis thaliana. The plants respond by inducing T3SS-dependent defense responses, including salicylic acid (SA)independent callose deposition, activation of the SA defense pathway, reactive oxygen species (ROS) accumulation, and part of the jasmonic acid/ethylene defense pathway. Several of these reactions are similar to what is observed in host plants. We show that the cell death triggered by E. amylovora on A. thaliana could not be simply explained by the recognition of AvrRpt2(ea) by the resistance gene product RPS2. We then analyzed the role of type three-secreted proteins (T3SPs) DspA/E, HrpN, and HrpW in the induction of cell death and defense reactions in A. thaliana following infection with the corresponding E. amylovora mutant strains. HrpN and DspA/E were found to play an important role in the induction of cell death, activation of defense pathways, and ROS accumulation. None of the T3SPs tested played a major role in the induction of SA-independent callose deposition. The relative importance of T3SPs in A. thaliana is correlated with their relative importance in the disease process on host plants, indicating that A. thaliana can be used as a model to study their role.