title: Rice OsFLS2-Mediated Perception of Bacterial Flagellins Is Evaded by Xanthomonas oryzae pvs. oryzae and oryzicola.
abstract: Bacterial flagellins are often recognized by the receptor kinase FLAGELLIN SENSITIVE2 (FLS2) and activate MAMP-triggered immunity in dicotyledonous plants. However, the capacity of monocotyledonous rice to recognize flagellins of key rice pathogens and its biological relevance remain poorly understood. We demonstrate that ectopically expressed OsFLS2 in Arabidopsis senses the eliciting flg22 peptide and in vitro purified Acidovorax avenae (Aa) flagellin in an expression level-dependent manner, but does not recognize purified flagellins or derivative flg22(Xo) peptides of Xanthomonas oryzae pvs. oryzae (Xoo) and oryzicola (Xoc). Consistently, the flg22 peptide and purified Aa flagellin, but not Xoo/Xoc flagellins, induce various immune responses such as defense gene induction and MAPK activation in rice. Perception of flagellin by rice does induce strong resistance to Xoo infection, as shown after pre-treatment of rice leaves with Aa flagellin. OsFLS2 was found to differ from AtFLS2 in its perception specificities or sensitivities to different flg22 sequences. In addition, post-translational modification of Xoc flagellin was altered by deletion of glycosyltransferase-encoding rbfC, but this had little effect on Xoc motility and rpfC mutation did not detectably reduce Xoc virulence on rice. Deletion of flagellin-encoding fliC from Xoo/Xoc blocked swimming motility but also did not significantly alter Xoo/Xoc virulence. These results suggest that Xoo/Xoc carry flg22-region amino acid changes that allow motility while evading the ancient flagellin detection system in rice, which retains recognition capacity for other bacterial pathogens.
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China.
authors.forename: Shanzhi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China.
authors.forename: Huiqin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Lu
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Rice Research Institute, Shandong Academy of Agricultural Science, Jinan 250100, Shandong Province, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, Hunan Province, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Rice Research Institute, Shandong Academy of Agricultural Science, Jinan 250100, Shandong Province, China.
authors.forename: Shiyong
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China.
authors.forename: Zejian
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Department of Plant Pathology, University of Wisconsin, Madison, WI 53706, USA.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Bent
authors.affiliation: Department of Plant Pathology, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, China; Key Laboratory of Plant Pathology, Ministry of Agriculture, China Agricultural University, Beijing 100193, China. Electronic address: wxs@cau.edu.cn.
authors.forename: Wenxian
authors.initials: W
authors.lastname: Sun
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D001665:Binding Sites; D042621:Comamonadaceae / Q000235:genetics / Q000502:physiology; D000066630:Ectopic Gene Expression; D005408:Flagellin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000201:enzymology* / Q000235:genetics; D010641:Phenotype; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D036226:Seedlings / Q000254:growth & development; D014974:Xanthomonas / Q000235:genetics / Q000502:physiology*
chemical_list: D005408:Flagellin; D011494:Protein Kinases
keywords: OsFLS2; Xanthomonas oryzae; flagellin; perception specificity