Lee Kyounghee, Park Ok-Sun, Jung Su-Jin, Seo Pil Joon
Department of Bioactive Material Sciences and Research Center of Bioactive Materials, Chonbuk National University, Jeonju 561-756, Republic of Korea.
Department of Chemistry and Research Institute of Physics and Chemistry, Chonbuk National University, Jeonju 561-756, Republic of Korea.
J Plant Physiol. 2016 Feb 1;191:95-100. doi: 10.1016/j.jplph.2015.12.006. Epub 2015 Dec 15.
Chromatin structure determines the accessibility of transcriptional regulators to target DNA and contributes to regulation of gene expression. Posttranslational modifications of core histone proteins underlie the reversible changes in chromatin structure. Epigenetic regulation is closely associated with cellular differentiation. Consistently, we found that histone deacetylation is required for callus formation from leaf explants in Arabidopsis . Treatment with trichostatin A (TSA) led to defective callus formation on callus-inducing medium (CIM). Gene expression profiling revealed that a subset of HDAC genes, including HISTONE DEACETYLASE 9 (HDA9), HD-TUINS PROTEIN 1 (HDT1), HDT2, HDT4, and SIRTUIN 1 (SRT1), was significantly up-regulated in calli. In support of this, genetic mutations of HDA9 or HDT1 showed reduced capability of callus formation, probably owing to their roles in regulating auxin and embryonic and meristematic developmental signaling. Taken together, our findings suggest that histone deacetylation is intimately associated with the leaf-to-callus transition, and multiple signaling pathways are controlled by means of histone modification during cellular dedifferentiation.
染色质结构决定转录调节因子对靶DNA的可及性，并有助于基因表达的调控。核心组蛋白的翻译后修饰是染色质结构可逆变化的基础。表观遗传调控与细胞分化密切相关。与此一致的是，我们发现拟南芥叶外植体形成愈伤组织需要组蛋白去乙酰化。用曲古抑菌素A（TSA）处理导致在愈伤组织诱导培养基（CIM）上愈伤组织形成缺陷。基因表达谱分析显示，包括组蛋白去乙酰化酶9（HDA9）、HD-TUINS蛋白1（HDT1）、HDT2、HDT4和沉默信息调节因子1（SRT1）在内的一组HDAC基因在愈伤组织中显著上调。与此相符的是，HDA9或HDT1的基因突变显示愈伤组织形成能力降低，这可能是由于它们在调节生长素以及胚胎和分生组织发育信号传导中的作用。综上所述，我们的研究结果表明组蛋白去乙酰化与叶到愈伤组织的转变密切相关，并且在细胞去分化过程中多种信号通路通过组蛋白修饰受到调控。
