title: Arabidopsis putative deacetylase AtSRT2 regulates basal defense by suppressing PAD4, EDS5 and SID2 expression.
abstract: The silent information regulator protein (Sir2) and its homologs are NAD(+)-dependent deacetylase enzymes that play important roles in a variety of physiological processes. However, the functions of the Sir2 family in plants are poorly understood. Here, we report that Arabidopsis AtSRT2, a homolog of yeast Sir2, negatively regulates plant basal defense against the pathogen Pseudomonas syringae pv. tomato DC3000 (PstDC3000). In response to PstDC3000 infection, the expression of AtSRT2 was down-regulated in a salicylic acid (SA)-independent manner. In addition, knock-out of AtSRT2 (srt2) enhanced resistance against PstDC3000 and increased expression of pathogenesis-related gene 1 (PR1). Conversely, overexpression of AtSRT2 resulted in hypersusceptibility to PstDC3000 and impaired PR1 induction. Consistent with this phenotype, expression of PAD4, EDS5 and SID2, three essential genes in the SA biosynthesis pathway, were increased in the srt2 mutant and decreased in AtSRT2-overexpressing plants. Taken together, these results demonstrate that AtSRT2 is a negative regulator of basal defense, possibly by suppressing SA biosynthesis.
authors.affiliation: National Laboratory of Protein Engineering and Plant Genetic Engineering, National Center for Plant Gene Research (Beijing), Peking-Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology, College of Life Sciences, Peking University, Beijing, PR China.
authors.forename: Chunzheng
authors.initials: C
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
authors.forename: Jianguo
authors.initials: J
authors.lastname: Wu
authors.forename: Jianli
authors.initials: J
authors.lastname: Dai
authors.forename: Chunhong
authors.initials: C
authors.lastname: Wei
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000276:immunology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D056545:Group III Histone Deacetylases / Q000235:genetics / Q000378:metabolism*; D007113:Immunity, Innate; D016254:Mutagenesis, Insertional; D044224:Pseudomonas syringae / Q000472:pathogenicity; D018749:RNA, Plant / Q000235:genetics; D020156:Salicylic Acid / Q000378:metabolism; D037761:Sirtuins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D018749:RNA, Plant; D056545:Group III Histone Deacetylases; C000592615:SRT2 protein, Arabidopsis; D037761:Sirtuins; D020156:Salicylic Acid