Universidad de los Andes, Laboratorio de Micología y Fitopatología de la Universidad de los Andes, 111711 Bogotá, Colombia.
Institut de Recherche pour le De´veloppement (IRD), Cirad, Universite´ Montpellier, Interactions Plantes Microorganismes Environnement (IPME), 34394, Montpellier, France.
Mol Plant Pathol. 2018 Mar;19(3):593-606. doi: 10.1111/mpp.12545. Epub 2017 Apr 5.
Xanthomonas axonopodis pv. manihotis (Xam) causes cassava bacterial blight, the most important bacterial disease of cassava. Xam, like other Xanthomonas species, requires type III effectors (T3Es) for maximal virulence. Xam strain CIO151 possesses 17 predicted T3Es belonging to the Xanthomonas outer protein (Xop) class. This work aimed to characterize nine Xop effectors present in Xam CIO151 for their role in virulence and modulation of plant immunity. Our findings demonstrate the importance of XopZ, XopX, XopAO1 and AvrBs2 for full virulence, as well as a redundant function in virulence between XopN and XopQ in susceptible cassava plants. We tested their role in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) using heterologous systems. AvrBs2, XopR and XopAO1 are capable of suppressing PTI. ETI suppression activity was only detected for XopE4 and XopAO1. These results demonstrate the overall importance and diversity in functions of major virulence effectors AvrBs2 and XopAO1 in Xam during cassava infection.
黄单胞菌木薯致病变种(Xam)引起木薯细菌性枯萎病,这是木薯最重要的细菌性疾病。Xam 与其他黄单胞菌一样,需要 III 型效应子(T3Es)才能达到最大毒力。Xam 菌株 CIO151 拥有 17 种预测的 T3E,属于黄单胞菌外蛋白(Xop)类。本工作旨在研究 Xam CIO151 中存在的 9 种 Xop 效应子在毒力和植物免疫调节中的作用。我们的研究结果表明 XopZ、XopX、XopAO1 和 AvrBs2 对完全毒力的重要性,以及在感病木薯植物中 XopN 和 XopQ 在毒力方面的冗余功能。我们使用异源系统测试了它们在病原体相关分子模式(PAMP)触发免疫(PTI)和效应物触发免疫(ETI)中的作用。AvrBs2、XopR 和 XopAO1 能够抑制 PTI。仅检测到 XopE4 和 XopAO1 具有 ETI 抑制活性。这些结果表明,在木薯感染过程中,主要毒力效应子 AvrBs2 和 XopAO1 在 Xam 中具有重要的整体功能和多样性。