title: VASCULAR-RELATED NAC-DOMAIN7 directly regulates the expression of a broad range of genes for xylem vessel formation.
abstract: The Arabidopsis thaliana NAC domain transcription factor, VASCULAR-RELATED NAC-DOMAIN7 (VND7), acts as a key regulator of xylem vessel differentiation. In order to identify direct target genes of VND7, we performed global transcriptome analysis using Arabidopsis transgenic lines in which VND7 activity could be induced post-translationally. This analysis identified 63 putative direct target genes of VND7, which encode a broad range of proteins, such as transcription factors, IRREGULAR XYLEM proteins and proteolytic enzymes, known to be closely associated with xylem vessel formation. Recombinant VND7 protein binds to several promoter sequences present in candidate direct target genes: specifically, in the promoter of XYLEM CYSTEINE PEPTIDASE1, two distinct regions were demonstrated to be responsible for VND7 binding. We also found that expression of VND7 restores secondary cell wall formation in the fiber cells of inflorescence stems of nst1 nst3 double mutants, as well as expression of NAC SECONDARY WALL THICKENING PROMOTING FACTOR3 (NST3, however, the vessel-type secondary wall deposition was observed only as a result of VND7 expression. These findings indicated that VND7 upregulates, directly and/or indirectly, many genes involved in a wide range of processes in xylem vessel differentiation, and that its target genes are partially different from those of NSTs.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Mitsuda
authors.forename: Misato
authors.initials: M
authors.lastname: Ohtani
authors.forename: Masaru
authors.initials: M
authors.lastname: Ohme-Takagi
authors.forename: Ko
authors.initials: K
authors.lastname: Kato
authors.forename: Taku
authors.initials: T
authors.lastname: Demura
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002473:Cell Wall / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism; D058526:Plant Vascular Bundle / Q000254:growth & development; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D052584:Xylem / Q000254:growth & development*
chemical_list: D029681:Arabidopsis Proteins; C519877:NST3 protein, Arabidopsis; D014157:Transcription Factors; C420969:CESA8 protein, Arabidopsis; D005964:Glucosyltransferases