Role of the penetration-resistance genes PEN1, PEN2 and PEN3 in the hypersensitive response and race-specific resistance in Arabidopsis thaliana
Role of the penetration-resistance genes PEN1, PEN2 and PEN3 in the hypersensitive response and race-specific resistance in Arabidopsis thaliana
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DOI：
10.1111/tpj.12571
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发表时间：
2014-08-01
期刊：
影响因子：
7.2
通讯作者：
Andersson, Mats X.
中科院分区：
文献类型：
--
作者：
Johansson, Oskar N.;Fantozzi, Elena;Andersson, Mats X.
植物有很强的识别和防御入侵微生物的能力。适应的植物病原体分泌效应分子来抑制宿主的免疫系统。这些分子可以被宿主编码的抗性蛋白识别，然后以过敏反应（HR）的形式触发防御，导致感染部位的宿主组织的程序性细胞死亡。已发现三种蛋白质PEN1、PEN2和PEN3在针对非适应性白粉病Blumeria graminis fsp的基于细胞壁的防御中充当中心组分。大麦（Bgh）。我们发现，三个PEN基因中任何一个的功能缺失突变都会导致拟南芥中由卵菌和细菌病原体的效应子识别引发的过敏性细胞死亡减少。这些突变有相当大的累加效应。在pen2 pen3和pen1 pen3双突变体中，由AvrRpm1识别诱导的HR几乎完全被废除，并且细胞死亡的损失可能与吲哚硫代葡萄糖苷分解产物有关。然而，在围栏双突变体的HR的损失并没有影响植物的能力，限制细菌的生长，而对无毒分离株的卵菌Hyaloperonospora arabidopsidis的抗性强烈受损。相比之下，双重和三重突变体在Bgh作用下表现出不同程度的失控细胞死亡。综上所述，我们的结果表明，这三个基因PEN1，PEN2和PEN3在功能上超出了它们先前在基于细胞壁的防御非宿主病原体中的功能。
Plants are highly capable of recognizing and defending themselves against invading microbes. Adapted plant pathogens secrete effector molecules to suppress the host's immune system. These molecules may be recognized by host-encoded resistance proteins, which then trigger defense in the form of the hypersensitive response (HR) leading to programmed cell death of the host tissue at the infection site. The three proteins PEN1, PEN2 and PEN3 have been found to act as central components in cell wall-based defense against the non-adapted powdery mildew Blumeria graminis fsp. hordei (Bgh). We found that loss of function mutations in any of the three PEN genes cause decreased hypersensitive cell death triggered by recognition of effectors from oomycete and bacterial pathogens in Arabidopsis. There were considerable additive effects of the mutations. The HR induced by recognition of AvrRpm1 was almost completely abolished in the pen2 pen3 and pen1 pen3 double mutants and the loss of cell death could be linked to indole glucosinolate breakdown products. However, the loss of the HR in pen double mutants did not affect the plants' ability to restrict bacterial growth, whereas resistance to avirulent isolates of the oomycete Hyaloperonospora arabidopsidis was strongly compromised. In contrast, the double and triple mutants demonstrated varying degrees of run-away cell death in response to Bgh. Taken together, our results indicate that the three genes PEN1, PEN2 and PEN3 extend in functionality beyond their previously recognized functions in cell wall-based defense against non-host pathogens.