Lysin Motif-Containing Proteins LYP4 and LYP6 Play Dual Roles in Peptidoglycan and Chitin Perception in Rice Innate Immunity
Lysin Motif-Containing Proteins LYP4 and LYP6 Play Dual Roles in Peptidoglycan and Chitin Perception in Rice Innate Immunity
复制标题
含有赖氨酸基序的蛋白质 LYP4 和 LYP6 在水稻先天免疫中的肽聚糖和甲壳质感知中发挥双重作用
DOI：
10.1105/tpc.112.102475
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发表时间：
2012-08-01
期刊：
影响因子：
11.6
通讯作者：
Wang, Hong-Bin
中科院分区：
文献类型：
--
作者：
Liu, Bing;Li, Jian-Feng;Wang, Hong-Bin
植物先天免疫依赖于通过植物细胞表面的模式识别受体（PRRs）成功检测入侵微生物的微生物相关分子模式（MAMPs）。在这里，我们报道了两个同源的水稻（Oryza sativa）溶酶基序蛋白LYP4和LYP6，作为双功能的PRRs传感细菌肽聚糖（PGN）和真菌几丁质。活细胞成像和微粒体分离一致地揭示了这些蛋白在水稻细胞中的质膜定位。这两个基因的转录可以在暴露于细菌病原体或多种MAMPs时迅速诱导。这两种蛋白在体外选择性结合PGN和几丁质，但不结合脂多糖（LPS）。因此，LYP的沉默特异性地损害了PGN-或几丁质，而不是lps诱导的水稻防御反应，包括活性氧的产生、防御基因的激活和胼胝质沉积，导致水稻对细菌病原体米黄单胞菌和真菌病原体米大孔菌的抗性降低。有趣的是，过量的PGN预处理显著减弱了水稻细胞对几丁质而不是鞭毛蛋白的碱化反应；反之，几丁质预处理会减弱水稻对PGN的反应，这表明PGN和几丁质参与了水稻中重叠的感知成分。总的来说，我们的数据支持LYP4和LYP6是水稻先天免疫中PGN和几丁质的混杂PRRs的观点。
Plant innate immunity relies on successful detection of microbe-associated molecular patterns (MAMPs) of invading microbes via pattern recognition receptors (PRRs) at the plant cell surface. Here, we report two homologous rice (Oryza sativa) lysin motif-containing proteins, LYP4 and LYP6, as dual functional PRRs sensing bacterial peptidoglycan (PGN) and fungal chitin. Live cell imaging and microsomal fractionation consistently revealed the plasma membrane localization of these proteins in rice cells. Transcription of these two genes could be induced rapidly upon exposure to bacterial pathogens or diverse MAMPs. Both proteins selectively bound PGN and chitin but not lipopolysaccharide (LPS) in vitro. Accordingly, silencing of either LYP specifically impaired PGN- or chitin-but not LPS-induced defense responses in rice, including reactive oxygen species generation, defense gene activation, and callose deposition, leading to compromised resistance against bacterial pathogen Xanthomonas oryzae and fungal pathogen Magnaporthe oryzae. Interestingly, pretreatment with excess PGN dramatically attenuated the alkalinization response of rice cells to chitin but not to flagellin; vice versa, pretreatment with chitin attenuated the response to PGN, suggesting that PGN and chitin engage overlapping perception components in rice. Collectively, our data support the notion that LYP4 and LYP6 are promiscuous PRRs for PGN and chitin in rice innate immunity.