Department of Life Science and Institute of Plant Biology; National Taiwan University; Taipei, Taiwan.
Plant Signal Behav. 2012 Sep 1;7(9):1070-2. doi: 10.4161/psb.21013. Epub 2012 Aug 17.
Plant stomata function in disease resistance by restricting bacteria entry inside leaves. During plant-bacteria interactions, stomatal closure is initiated by the recognition of Microbe-Associated Molecular Patterns (MAMPs). Recently, we have shown that the Lectin Receptor Kinase V.5 (LecRK-V.5) negatively regulates bacterium- and MAMP-induced stomatal closure upstream of Reactive Oxygen Species (ROS) production mediated by abscisic acid signaling. Closed stomata in lecrk-V.5 mutants are correlated with constitutive high level of ROS in guard cells. Consequently, lecrk-V.5 mutants are more resistant to hemi-biotrophic pathogen Pseudomonas syringae pv tomato DC3000 (Pst DC3000). In this report, we further investigate the role of LecRK-V.5 in resistance against necrotrophic bacteria Pectobacterium carotovorum ssp. carotovorum (Pcc). Upon surface-inoculation lecrk-V.5 mutants exhibited enhanced resistance against Pcc whereas a wild-type level of resistance was observed using infiltration-inoculation, an inoculation method that bypasses the epidermal barrier. Enhanced resistance of dip-inoculated lecrk-V.5 mutants against necrotrophic bacteria, that induce different defense responses than hemi-biotrophic bacteria, further suggests a possible role for LecRK-V.5 in stomatal immunity.
植物气孔通过限制细菌进入叶片内部来发挥抗病作用。在植物与细菌的相互作用中，气孔关闭是由微生物相关分子模式（MAMPs）的识别引发的。最近，我们已经表明，凝集素受体激酶 V.5（LecRK-V.5）通过脱落酸信号转导负调控由活性氧（ROS）产生介导的细菌和 MAMP 诱导的气孔关闭。在保卫细胞中，LecRK-V.5 突变体中的关闭气孔与组成性高水平的 ROS 相关。因此，LecRK-V.5 突变体对半生物营养性病原体丁香假单胞菌 pv 番茄 DC3000（Pst DC3000）的抗性更高。在本报告中，我们进一步研究了 LecRK-V.5 在对坏死性病原体果胶杆菌果胶亚种（Pcc）的抗性中的作用。在表面接种时，LecRK-V.5 突变体表现出对 Pcc 的增强抗性，而使用渗透接种（一种绕过表皮屏障的接种方法）则观察到野生型水平的抗性。与半生物营养性病原体相比，浸泡接种的 LecRK-V.5 突变体对诱导不同防御反应的坏死性病原体的增强抗性进一步表明，LecRK-V.5 可能在气孔免疫中发挥作用。
