Phytophthora infestans effector AVRblb2 prevents secretion of a plant immune protease at the haustorial interface
Phytophthora infestans effector AVRblb2 prevents secretion of a plant immune protease at the haustorial interface
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DOI：
10.1073/pnas.1112708109
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发表时间：
2011-12-20
影响因子：
11.1
通讯作者：
Kamoun, Sophien
中科院分区：
文献类型：
--
作者：
Bozkurt, Tolga O.;Schornack, Sebastian;Kamoun, Sophien
为了应对病原体的攻击，植物细胞在感染部位分泌抗微生物分子。然而，植物病原体如何干扰防御相关的局灶性分泌仍然知之甚少。在这里，我们表明，主机易位RXLR型效应蛋白AVRblb2的爱尔兰马铃薯饥荒病原体致病疫霉集中积累吸器周围，专门的感染结构，在植物细胞内形成，并通过干扰宿主防御的执行，促进毒力。AVRblb2通过靶向宿主木瓜蛋白酶样半胱氨酸蛋白酶C14并特异性地阻止其分泌到质外体中来显著增强宿主植物对致病疫霉的易感性。C14表达改变的植物对致病疫霉的易感性受到显著影响，其方式与C14在植物免疫中的积极作用一致。我们的研究结果指出了一种独特的防御策略，植物病原体用来中和分泌的宿主防御蛋白酶。效应子，如AVRblb2，可用作分子探针以剖析病原体穿透位点处的局灶性免疫应答。
In response to pathogen attack, plant cells secrete antimicrobial molecules at the site of infection. However, how plant pathogens interfere with defense-related focal secretion remains poorly known. Here we show that the host-translocated RXLR-type effector protein AVRblb2 of the Irish potato famine pathogen Phytophthora infestans focally accumulates around haustoria, specialized infection structures that form inside plant cells, and promotes virulence by interfering with the execution of host defenses. AVRblb2 significantly enhances susceptibility of host plants to P. infestans by targeting the host papain-like cysteine protease C14 and specifically preventing its secretion into the apoplast. Plants altered in C14 expression were significantly affected in susceptibility to P. infestans in a manner consistent with a positive role of C14 in plant immunity. Our findings point to a unique counterdefense strategy that plant pathogens use to neutralize secreted host defense proteases. Effectors, such as AVRblb2, can be used as molecular probes to dissect focal immune responses at pathogen penetration sites.