title: A NAC transcription factor and SNI1 cooperatively suppress basal pathogen resistance in Arabidopsis thaliana.
abstract: Transcriptional repression of pathogen defense-related genes is essential for plant growth and development. Several proteins are known to be involved in the transcriptional regulation of plant defense responses. However, mechanisms by which expression of defense-related genes are regulated by repressor proteins are poorly characterized. Here, we describe the in planta function of CBNAC, a calmodulin-regulated NAC transcriptional repressor in Arabidopsis. A T-DNA insertional mutant (cbnac1) displayed enhanced resistance to a virulent strain of the bacterial pathogen Pseudomonas syringae DC3000 (PstDC3000), whereas resistance was reduced in transgenic CBNAC overexpression lines. The observed changes in disease resistance were correlated with alterations in pathogenesis-related protein 1 (PR1) gene expression. CBNAC bound directly to the PR1 promoter. SNI1 (suppressor of nonexpressor of PR genes1, inducible 1) was identified as a CBNAC-binding protein. Basal resistance to PstDC3000 and derepression of PR1 expression was greater in the cbnac1 sni1 double mutant than in either cbnac1 or sni1 mutants. SNI1 enhanced binding of CBNAC to its cognate PR1 promoter element. CBNAC and SNI1 are hypothesized to work as repressor proteins in the cooperative suppression of plant basal defense.
authors: Division of Applied Life Science (BK21 Program), Gyeongsang National University, Jinju 660-701, Korea.
authors: Ho Soo
authors: HS
authors: Kim
authors: Hyeong Cheol
authors: HC
authors: Park
authors: Kyung Eun
authors: KE
authors: Kim
authors: Mi Soon
authors: MS
authors: Jung
authors: Hay Ju
authors: HJ
authors: Han
authors: Sun Ho
authors: SH
authors: Kim
authors: Young Sang
authors: YS
authors: Kwon
authors: Sunghwa
authors: S
authors: Bahk
authors: Jonguk
authors: J
authors: An
authors: Dong Won
authors: DW
authors: Bae
authors: Dae-Jin
authors: DJ
authors: Yun
authors: Sang-Soo
authors: SS
authors: Kwak
authors: Woo Sik
authors: WS
authors: Chung
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D060467:Disease Resistance / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D009687:Nuclear Proteins / Q000378:metabolism*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D011401:Promoter Regions, Genetic; D044224:Pseudomonas syringae; D012333:RNA, Messenger / Q000096:biosynthesis; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid
chemical_list: D029681:Arabidopsis Proteins; C577034:CBNAC protein, Arabidopsis; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C121026:SNI1 protein, Arabidopsis; D004247:DNA; D020156:Salicylic Acid