ATAF2, a NAC transcription factor, binds to the promoter and regulates NIT2 gene expression involved in auxin biosynthesis

• Published in: Molecules and cells 2012, 34(3), , pp.305-313
• Main Authors: Huh, S.U., Korea University, Seoul, Republic of Korea, Lee, S.B., Korea University, Seoul, Republic of Korea, Kim, H.H., Korea University, Seoul, Republic of Korea, Paek, K.H., Korea University, Seoul, Republic of Korea
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Aminohydrolases - genetics; Aminohydrolases - metabolism; ARABIDOPSIS; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; ATAF2; AUXINAS; AUXINE; AUXINS; Binding Sites; Biochemistry; Biomedical and Life Sciences; Biomedicine; Biotechnology; Cell Biology; Gene Expression Regulation, Plant; Genes, Reporter; Indoleacetic Acids - metabolism; Indoles - metabolism; Indoles - pharmacology; Life Sciences; Molecular Sequence Data; NAC transcription factor; Nitrilase; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Promoter Regions, Genetic; Repressor Proteins - genetics; Repressor Proteins - metabolism; Research Article; Transcription Factors - genetics; Transcription Factors - metabolism; 생물학
• ISSN: 1016-8478; 0219-1032
• DOI: 10.1007/s10059-012-0122-2

The transcription factor ATAF2, one of the plant specific NAC family genes, is known as repressor of pathogenesisrelated genes and responsive to the diverse defense-related hormones, pathogen infection, and wounding stress. Furthermore, it is important to consider that tryptophandependant IAA biosynthesis pathway can be activated by wounding and pathogen. We found that ATAF2pro::GUS reporter was induced upon indole-3-acetonitrile (IAN) treatments. And ataf2 mutant showed reduced sensitivity to IAN whereas 35S::ATAF2 plants showed hyper-sensitivity to IAN. IAN biosynthesis required nitrilase involved in the conversion of IAN to an auxin, indole-3-acetic acid (IAA). We found that the NIT2 gene was repressed in ataf2 knockout plants. Expression of both ATAF2 and NIT2 genes was induced by IAN treatment. Transgenic plants overexpressing ATAF2 showed up-regulated NIT2 expression. ATAF2 activated promoter of the NIT2 gene in Arabidopsis protoplasts. Electrophoretic mobility shift assay revealed that NIT2 promoter region from position -117 to -82 contains an ATAF2 binding site where an imperfect palindrome sequence was critical to the protein-DNA interaction. These findings indicate that ATAF2 regulates NIT2 gene expression via NIT2 promoter binding.