A NAC transcription factor and SNI1 cooperatively suppress basal pathogen resistance in Arabidopsis thaliana
A NAC transcription factor and SNI1 cooperatively suppress basal pathogen resistance in Arabidopsis thaliana
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DOI：
10.1093/nar/gks683
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发表时间：
2012-10-01
影响因子：
14.9
通讯作者：
Chung, Woo Sik
中科院分区：
文献类型：
--
作者：
Kim, Ho Soo;Park, Hyeong Cheol;Chung, Woo Sik
病原防御相关基因的转录抑制对植物的生长发育至关重要。已知有几种蛋白质参与植物防御反应的转录调控。然而，防御相关基因表达受抑制蛋白调控的机制尚不清楚。在这里，我们描述了CBNAC（一种钙调素调节的NAC转录抑制因子）在拟南芥中的植物功能。T-DNA插入突变体（cbna1）对丁香假单胞菌DC3000 （PstDC3000）的抗性增强，而转基因CBNAC过表达系的抗性降低。观察到的抗病性变化与致病相关蛋白1 （PR1）基因表达的改变有关。CBNAC直接与PR1启动子结合。SNI1 （suppressor of nonexpressor of PR genes1, inducible 1）被鉴定为cbnac结合蛋白。cbnac1 - sni1双突变体对PstDC3000的基础耐药性和PR1表达的下调高于cbnac1或sni1突变体。SNI1增强了CBNAC与其同源PR1启动子元件的结合。CBNAC和SNI1可能作为抑制蛋白协同抑制植物基础防御。
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.