title: A Phytophthora sojae Glycoside Hydrolase 12 Protein Is a Major Virulence Factor during Soybean Infection and Is Recognized as a PAMP.
abstract: We identified a glycoside hydrolase family 12 (GH12) protein, XEG1, produced by the soybean pathogen Phytophthora sojae that exhibits xyloglucanase and β-glucanase activity. It acts as an important virulence factor during P. sojae infection but also acts as a pathogen-associated molecular pattern (PAMP) in soybean (Glycine max) and solanaceous species, where it can trigger defense responses including cell death. GH12 proteins occur widely across microbial taxa, and many of these GH12 proteins induce cell death in Nicotiana benthamiana. The PAMP activity of XEG1 is independent of its xyloglucanase activity. XEG1 can induce plant defense responses in a BAK1-dependent manner. The perception of XEG1 occurs independently of the perception of ethylene-inducing xylanase. XEG1 is strongly induced in P. sojae within 30 min of infection of soybean and then slowly declines. Both silencing and overexpression of XEG1 in P. sojae severely reduced virulence. Many P. sojae RXLR effectors could suppress defense responses induced by XEG1, including several that are expressed within 30 min of infection. Therefore, our data suggest that PsXEG1 contributes to P. sojae virulence, but soybean recognizes PsXEG1 to induce immune responses, which in turn can be suppressed by RXLR effectors. XEG1 thus represents an apoplastic effector that is recognized via the plant's PAMP recognition machinery.
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhenchuan
authors.identifier: http://orcid.org/0000-0002-8478-2833
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Tianqiao
authors.initials: T
authors.lastname: Song
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Wenwu
authors.identifier: http://orcid.org/0000-0001-7347-8935
authors.initials: W
authors.lastname: Ye
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Suomeng
authors.identifier: http://orcid.org/0000-0002-9623-6776
authors.initials: S
authors.lastname: Dong
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing 210095, China.
authors.forename: Zhengguang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing 210095, China.
authors.forename: Daolong
authors.identifier: http://orcid.org/0000-0001-5226-6642
authors.initials: D
authors.lastname: Dou
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing 210095, China.
authors.forename: Xiaobo
authors.identifier: http://orcid.org/0000-0001-5803-5343
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Center for Genome Research and Biocomputing, Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331.
authors.forename: Brett M
authors.identifier: http://orcid.org/0000-0003-1549-2987
authors.initials: BM
authors.lastname: Tyler
authors.affiliation: Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing 210095, China wangyc@njau.edu.cn.
authors.forename: Yuanchao
authors.identifier: http://orcid.org/0000-0001-5803-5343
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001419:Bacteria / Q000201:enzymology; D002212:Capsicum / Q000378:metabolism; D016923:Cell Death; D060467:Disease Resistance; D006026:Glycoside Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D006868:Hydrolysis; D018551:Solanum lycopersicum / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D000069452:Pathogen-Associated Molecular Pattern Molecules / Q000378:metabolism*; D010838:Phytophthora / Q000201:enzymology* / Q000472:pathogenicity*; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity; D010940:Plant Proteins / Q000378:metabolism; D021382:Protein Sorting Signals; D013025:Glycine max / Q000166:cytology / Q000276:immunology* / Q000382:microbiology*; D014026:Nicotiana / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D014774:Virulence; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D000069452:Pathogen-Associated Molecular Pattern Molecules; D010940:Plant Proteins; D021382:Protein Sorting Signals; D037521:Virulence Factors; D006026:Glycoside Hydrolases