altered levels of histone deacetylase oshdt1 affect differential gene expression patterns in hybrid rice改变水平的组蛋白脱乙酰酶oshdt1影响微分在杂交水稻基因表达模式.pdfVIP

Altered Levels of Histone Deacetylase OsHDT1 Affect Differential Gene Expression Patterns in Hybrid Rice 1 1 1 1 1,2 Chen Li , Limin Huang , Caiguo Xu , Yu Zhao , Dao-Xiu Zhou * ´ 1 National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, China, 2 Institut de Biologie des Plantes, UMR8618, Universite Paris sud 11, CNRS, Orsay, France Abstract Hybrids between different inbred varieties display novel patterns of gene expression resulted from parental variation in allelic nucleotide sequences. To study the function of chromatin regulators in hybrid gene expression, the histone deacetylase gene OsHDT1 whose expression displayed a circadian rhythm was over-expressed or inactivated by RNAi in an elite rice parent. Increased OsHDT1 expression did not affect plant growth in the parent but led to early flowering in the hybrid. Nonadditive up-regulation of key flowering time genes was found to be related to flowering time of the hybrid. Over-expression of OsHDT1 repressed the nonadditive expression of the key flowering repressors in the hybrid (i.e. OsGI and Hd1) inducing early flowering. Analysis of histone acetylation suggested that OsHDT1 over-expression might promote deacetylation on OsGI and Hd1 chromatin during the peak expression phase. High throughput differential gene expression analysis revealed that altered OsHDT1 levels affected nonadditive expression of many genes in the hybrid. These data demonstrate that nonadditive gene expression was involved in flowering time control in the hybrid r