title: Expression and function of HD2-type histone deacetylases in Arabidopsis development.
abstract: HD2 (histone deacetylase) proteins are plant-specific histone deacetylases (HDACs). The Arabidopsis genome contains four HD2 genes, namely HD2A, HD2B, HD2C, and HD2D. We have previously demonstrated that HD2A, HD2B, and HD2C can repress transcription directly by targeting to promoters in planta. Here, we show that the N-terminal conserved motif (EFWG) and histidine 25 (H25), a potential catalytic residue, were important for the gene repression activity of HD2A. In situ hybridization indicated that HD2A, HD2B, and HD2C were expressed in ovules, embryos, shoot apical meristems, and primary leaves. Furthermore, all three genes were strongly induced during the process of somatic embryogenesis. HD2D mRNA was only detected in the stems and flowers with young siliques and may have adopted different functions. Using green fluorescent protein (GFP) fusions, we demonstrated that HD2A, HD2B, and HD2C accumulated in the nuclei of Arabidopsis cells. Overexpression of 35S::GFP-HD2A in transgenic Arabidopsis plants generated pleiotropic developmental abnormalities, including abnormal leaves, delayed flowering, and aborted seed development. The data showed that normal pattern of HD2 expression was essential for normal plant development and that HD2A, HD2B, and HD2C may be needed for embryogenesis and embryo development. Reverse transcriptase (RT)-PCR analysis revealed that a number of genes involved in seed development and maturation were repressed in the 35S::GFP-HD2A plants, supporting a role of HD2A in the regulation of gene expression during seed development.
authors.affiliation: Department of Biology, West Virginia University, Morgantown, WV 26506, USA.
authors.forename: Changhe
authors.initials: C
authors.lastname: Zhou
authors.forename: Helene
authors.initials: H
authors.lastname: Labbe
authors.forename: Sunandini
authors.initials: S
authors.lastname: Sridha
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Lining
authors.initials: L
authors.lastname: Tian
authors.forename: Marysia
authors.initials: M
authors.lastname: Latoszek-Green
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.forename: Daniel
authors.initials: D
authors.lastname: Brown
authors.forename: Brian
authors.initials: B
authors.lastname: Miki
authors.forename: Keqiang
authors.initials: K
authors.lastname: Wu
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D017931:DNA Primers; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases / Q000235:genetics* / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; D012097:Repressor Proteins; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases