title: Cucumber Pti1-L is a cytoplasmic protein kinase involved in defense responses and salt tolerance.
abstract: Homologs of the cytoplasmic protein kinase Pti1 are found in diverse plant species. A clear role of Pti1 in plant defense response has not been established. We identified a Pti1 homolog in cucumber (CsPti1-L). CsPti1-L expression was induced when cucumber plants were challenged with the fungal pathogen Sphaerotheca fuliginea or with salt treatment. CsPti1-L expression in cucumber leaves also was induced by methyl jasmonate, salicylic acid, and abscisic acid. CsPti1-L exhibited autophosphorylation activity and was targeted to the cytoplasm. Transgenic Nicotiana benthamiana expressing CsPti1-L exhibited greater cell death and increased ion leakage in response to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000, resistance to Botrytis cinerea infection, and higher tolerance to salt stress. RT-PCR analysis of transgenic N. benthamiana overexpressing CsPti1-L revealed constitutive upregulation of multiple genes involved in plant-defense and osmotic-stress responses. Our results suggest a functional role for CsPti1-L as a positive regulator of pathogen-defense and salt-stress responses.
authors.affiliation: Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Sang-Keun
authors.initials: SK
authors.lastname: Oh
authors.affiliation: Korea Research Institute of Bioscience & Biotechnology, Plant Systems Engineering Research Center, Daejeon 305-806, Republic of Korea.
authors.forename: Hyun A
authors.initials: HA
authors.lastname: Jang
authors.affiliation: Korea Research Institute of Bioscience & Biotechnology, Plant Systems Engineering Research Center, Daejeon 305-806, Republic of Korea.
authors.forename: Sang Sook
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Korea Research Institute of Bioscience & Biotechnology, Plant Systems Engineering Research Center, Daejeon 305-806, Republic of Korea.
authors.forename: Hye Sun
authors.initials: HS
authors.lastname: Cho
authors.affiliation: Department of Life Science, Ewha Womans University, Seoul 120-750, Republic of Korea.
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Plant Science, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
authors.forename: Doil
authors.initials: D
authors.lastname: Choi
authors.affiliation: Korea Research Institute of Bioscience & Biotechnology, Plant Systems Engineering Research Center, Daejeon 305-806, Republic of Korea. Electronic address: sykwon@kribb.re.kr.
authors.forename: Suk-Yoon
authors.initials: SY
authors.lastname: Kwon
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000502:physiology; D020171:Botrytis / Q000502:physiology; D016923:Cell Death; D002734:Chlorophyll / Q000378:metabolism; D018553:Cucumis sativus / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000502:physiology; D003593:Cytoplasm / Q000201:enzymology; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000502:physiology; D055049:Salt Tolerance; D036226:Seedlings / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology; D016415:Sequence Alignment; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000276:immunology / Q000502:physiology
chemical_list: D010940:Plant Proteins; D002734:Chlorophyll; D011494:Protein Kinases
keywords: Cell death; CsPti1-L; Cytoplasmic protein kinase; Defense responses; Salt tolerance