title: The calmodulin-binding transcription factor OsCBT suppresses defense responses to pathogens in rice.
abstract: We previously isolated the OsCBT gene, which encodes a calmodulin (CaM)-binding protein, from a rice expression library constructed from fungal elicitor-treated rice suspension cells. In order to understand the function of OsCBT in rice, we isolated and characterized a T-DNA insertion mutant allele named oscbt-1. The oscbt-1 mutant exhibits reduced levels of OsCBT transcripts and no significant morphological changes compared to wild-type plant although the growth of the mutant is stunted. However, oscbt-1 mutants showed significant resistance to two major rice pathogens. The growth of the rice blast fungus Magnaporthe grisea, as well as the bacterial pathogen Xanthomonas oryzae pv. oryzae was significantly suppressed in oscbt-1 plants. Histochemical analysis indicated that the hypersensitive-response was induced in the oscbt-1 mutant in response to compatible strains of fungal pathogens. OsCBT expression was induced upon challenge with fungal elicitor. We also observed significant increase in the level of pathogenesis-related genes in the oscbt-1 mutant even under pathogen-free condition. Taken together, the results support an idea that OsCBT might act as a negative regulator on plant defense.
authors.affiliation: Division of Applied Life Science (Brain Korea 21 program), Plant Molecular Biology and Biotechnology Research Center and Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Sung Cheol
authors.initials: SC
authors.lastname: Koo
authors.forename: Man Soo
authors.initials: MS
authors.lastname: Choi
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Chun
authors.forename: Dong Bum
authors.initials: DB
authors.lastname: Shin
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Park
authors.forename: Yul Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Hyang-Mi
authors.initials: HM
authors.lastname: Park
authors.forename: Hak Soo
authors.initials: HS
authors.lastname: Seo
authors.forename: Jong Tae
authors.initials: JT
authors.lastname: Song
authors.forename: Kyu Young
authors.initials: KY
authors.lastname: Kang
authors.forename: Dae-Jin
authors.initials: DJ
authors.lastname: Yun
authors.forename: Woo Sik
authors.initials: WS
authors.lastname: Chung
authors.forename: Moo Je
authors.initials: MJ
authors.lastname: Cho
authors.forename: Min Chul
authors.initials: MC
authors.lastname: Kim
mesh_terms: D002148:Calmodulin-Binding Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D048708:Cell Growth Processes / Q000235:genetics; D004269:DNA, Bacterial; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D007108:Immune Tolerance; D007109:Immunity / Q000235:genetics; D020082:Magnaporthe / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity; D050505:Mutant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012275:Oryza / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014974:Xanthomonas / Q000254:growth & development / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D002148:Calmodulin-Binding Proteins; D004269:DNA, Bacterial; D050505:Mutant Proteins; D010940:Plant Proteins; C036483:T-DNA; D014157:Transcription Factors