title: Label-free quantitative secretome analysis of Xanthomonas oryzae pv. oryzae highlights the involvement of a novel cysteine protease in its pathogenicity.
abstract: Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most devastating diseases resulting in a huge loss of the total rice productivity. The initial interaction between rice and Xoo takes place in the host apoplast and is mediated primarily by secretion of various proteins from both partners. Yet, such secretory proteins remain to be largely identified and characterized. This study employed a label-free quantitative proteomics approach and identified 404 and 323 Xoo-secreted proteins from in vitro suspension-cultured cells and in planta systems, respectively. Gene Ontology analysis showed their involvement primarily in catalytic, transporter, and ATPase activities. Of a particular interest was a Xoo cysteine protease (XoCP), which showed dramatic increase in its protein abundance in planta upon Xoo interaction with a susceptible rice cultivar. Knock-out mutants of XoCP showed reduced pathogenicity on rice, highlighting its potential involvement in Xoo virulence. Besides, a parallel analysis of in planta rice-secreted proteins resulted in identification of 186 secretory proteins mainly associated with the catalytic, antioxidant, and electron carrier activities. Identified secretory proteins were exploited to shed light on their possible role in the rice-Xoo interaction, and that further deepen our understanding of such interaction.
  
  
  
  Xanthomonas oryzae pv. oryzae (Xoo), causative agent of bacterial blight disease, results in a huge loss of the total rice productivity. Using a label-free quantitative proteomics approach, we identified 727 Xoo- and 186 rice-secreted proteins. Functional annotation showed Xoo secreted proteins were mainly associated with the catalytic, transporter, and ATPase activities while the rice secreted proteins were mainly associated with the catalytic, antioxidant, and electron carrier activities. A novel Xoo cysteine protease (XoCP) was identified, showing dramatic increase in its protein abundance in planta upon Xoo interaction with a susceptible rice cultivar. Knock-out mutants of XoCP showed reduced pathogenicity on rice, highlighting its potential involvement in Xoo virulence.
authors.affiliation: Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linneweg 10, Cologne 50829, Germany.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang 627-707, South Korea.
authors.forename: Ravi
authors.initials: R
authors.lastname: Gupta
authors.affiliation: Plant Proteomics Group, Max Planck Institute for Plant Breeding Research, Carl-von-Linneweg 10, Cologne 50829, Germany.
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.affiliation: Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang 627-707, South Korea.
authors.forename: Hyun-Hye
authors.initials: HH
authors.lastname: Huh
authors.affiliation: Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang 627-707, South Korea.
authors.forename: So Eui
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Carl-von-Linneweg 10, Cologne 50829, Germany.
authors.forename: Jingni
authors.initials: J
authors.lastname: Wu
authors.affiliation: Research Laboratory for Biotechnology and Biochemistry (RLABB), GPO 13265, Kathmandu 44600, Nepal; GRADE (Global Research Arch for Developing Education) Academy, Pvt. Ltd, Adarsh Nagar-13, Birgunj 44300, Nepal.
authors.forename: Ganesh Kumar
authors.initials: GK
authors.lastname: Agrawal
authors.affiliation: Research Laboratory for Biotechnology and Biochemistry (RLABB), GPO 13265, Kathmandu 44600, Nepal; GRADE (Global Research Arch for Developing Education) Academy, Pvt. Ltd, Adarsh Nagar-13, Birgunj 44300, Nepal; Faculty of Health and Sport Sciences, Tsukuba International Academy for Sport Studies (TIAS), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8574, Ibaraki, Japan.
authors.forename: Randeep
authors.initials: R
authors.lastname: Rakwal
authors.affiliation: Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju, South Korea.
authors.forename: Kyu Young
authors.initials: KY
authors.lastname: Kang
authors.affiliation: National Academy of Agricultural Science, Rural Development Administration, Suwon 441-707, South Korea. Electronic address: srpark@korea.kr.
authors.forename: Sang-Ryeol
authors.initials: SR
authors.lastname: Park
authors.affiliation: Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang 627-707, South Korea. Electronic address: stkim71@pusan.ac.kr.
authors.forename: Sun Tae
authors.initials: ST
authors.lastname: Kim
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism; D057056:Cysteine Proteases / Q000502:physiology* / Q000633:toxicity; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000032:analysis / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D014774:Virulence; D014974:Xanthomonas / Q000201:enzymology / Q000378:metabolism* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D010940:Plant Proteins; D057056:Cysteine Proteases
keywords: Bacterial blight; Pathogenicity; Proteomics; Rice; Secretome