Blocking histone deacetylation in Arabidopsis induces pleiotropic effects on plant gene regulation and development.
Histone acetylation and deacetylation play essential roles in eukaryotic gene regulation. Reversible modifications of core histones are catalyzed by two intrinsic enzymes, histone acetyltransferase and histone deacetylase (HD). In general, histone deacetylation is related to transcriptional gene silencing, whereas acetylation correlates with gene activation. We produced transgenic plants expressing the antisense Arabidopsis HD (AtHD1) gene. AtHD1 is a homolog of human HD1 and RPD3 global transcriptional regulator in yeast. Expression of the antisense AtHD1 caused dramatic reduction in endogenous AtHD1 transcription, resulting in accumulation of acetylated histones, notably tetraacetylated H4. Reduction in AtHD1 expression and AtHD1 production and changes in acetylation profiles were associated with various developmental abnormalities, including early senescence, ectopic expression of silenced genes, suppression of apical dominance, homeotic changes, heterochronic shift toward juvenility, flower defects, and male and female sterility. Some of the phenotypes could be attributed to ectopic expression of tissue-specific genes (e.g., SUPERMAN) in vegetative tissues. No changes in genomic DNA methylation were detected in the transgenic plants. These results suggest that AtHD1 is a global regulator, which controls gene expression during development through DNA-sequence independent or epigenetic mechanisms in plants. In addition to DNA methylation, histone modifications may be involved in a general regulatory mechanism responsible for plant plasticity and variation in nature.
Tian
L
L
Genetics Program and Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843-2474, USA.
Chen
Z J
ZJ
D000107:Acetylation; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins; D019175:DNA Methylation; D016373:DNA, Antisense / Q000235:genetics; D015536:Down-Regulation; D018628:Gene Dosage; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant / Q000235:genetics; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D008969:Molecular Sequence Data; D010641:Phenotype; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation
D029681:Arabidopsis Proteins; D016373:DNA, Antisense; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D010940:Plant Proteins; D014157:Transcription Factors; C096661:superman protein, Arabidopsis; D006655:Histone Deacetylases