National Research Council of Italy, Institute of Plant Genetics, Research Division Portici, 80055 Portici, Italy.
Plant Physiol. 2013 Sep;163(1):431-40. doi: 10.1104/pp.113.221713. Epub 2013 Jul 22.
Histone modifications are involved in the regulation of many processes in eukaryotic development. In this work, we provide evidence that AtHDA7, a HISTONE DEACETYLASE (HDAC) of the Reduced Potassium Dependency3 (RPD3) superfamily, is crucial for female gametophyte development and embryogenesis in Arabidopsis (Arabidopsis thaliana). Silencing of AtHDA7 causes degeneration of micropylar nuclei at the stage of four-nucleate embryo sac and delay in the progression of embryo development, thereby bringing the seed set down in the Athda7-2 mutant. Furthermore, AtHDA7 down- and up-regulation lead to a delay of growth in postgermination and later developmental stages. The Athda7-2 mutation that induces histone hyperacetylation significantly increases the transcription of other HDACs (AtHDA6 and AtHDA9). Moreover, silencing of AtHDA7 affects the expression of ARABIDOPSIS HOMOLOG OF SEPARASE (AtAESP), previously demonstrated to be involved in female gametophyte and embryo development. However, chromatin immunoprecipitation analysis with acetylated H3 antibody provided evidence that the acetylation levels of H3 at AtAESP and HDACs does not change in the mutant. Further investigations are essential to ascertain the mechanism by which AtHDA7 affects female gametophyte and embryo development.
组蛋白修饰参与真核生物发育过程中的许多调控。在这项工作中，我们提供了证据表明 AtHDA7，一个 REDUCED POTASSIUM 依赖性 3（RPD3）超家族的组蛋白去乙酰化酶（HDAC），对于拟南芥（Arabidopsis thaliana）雌性配子体发育和胚胎发生至关重要。AtHDA7 的沉默导致四核胚囊阶段的珠孔核退化和胚胎发育进程的延迟，从而导致 Athda7-2 突变体中的种子结实减少。此外，AtHDA7 的下调和上调导致萌发后和后期发育阶段的生长延迟。诱导组蛋白过度乙酰化的 Athda7-2 突变显著增加了其他 HDAC（AtHDA6 和 AtHDA9）的转录。此外，AtHDA7 的沉默会影响先前被证明参与雌性配子体和胚胎发育的 ARABIDOPSIS HOMOLOG OF SEPARASE（AtAESP）的表达。然而，用乙酰化 H3 抗体进行的染色质免疫沉淀分析提供了证据表明，AtAESP 和 HDACs 中的 H3 乙酰化水平在突变体中没有改变。进一步的研究对于确定 AtHDA7 影响雌性配子体和胚胎发育的机制至关重要。
