Plant Molecular Biology and Biotechnology Laboratory, ARC Centre of Excellence for Integrative Legume Research, Melbourne School of Land and Environment, the University of Melbourne, Parkville, Victoria, Australia.
PLoS One. 2013 Oct 16;8(10):e77502. doi: 10.1371/journal.pone.0077502. eCollection 2013.
Epigenetics has been recognised to play vital roles in many plant developmental processes, including floral initiation through the epigenetic regulation of gene expression. The histone modifying proteins that mediate these modifications involve the SET domain-containing histone methyltransferases, JmjC domain-containing demethylase, acetylases and deacetylases. In addition, RNA interference (RNAi)-associated genes are also involved in epigenetic regulation via RNA-directed DNA methylation and post-transcriptional gene silencing. Soybean, a major crop legume, requires a short day to induce flowering. How histone modifications regulate the plant response to external cues that initiate flowering is still largely unknown. Here, we used RNA-seq to address the dynamics of transcripts that are potentially involved in the epigenetic programming and RNAi mediated gene silencing during the floral initiation of soybean. Soybean is a paleopolyploid that has been subjected to at least two rounds of whole genome duplication events. We report that the expanded genomic repertoire of histone modifiers and RNA silencing genes in soybean includes 14 histone acetyltransferases, 24 histone deacetylases, 47 histone methyltransferases, 15 protein arginine methyltransferases, 24 JmjC domain-containing demethylases and 47 RNAi-associated genes. To investigate the role of these histone modifiers and RNA silencing genes during floral initiation, we compared the transcriptional dynamics of the leaf and shoot apical meristem at different time points after a short-day treatment. Our data reveal that the extensive activation of genes that are usually involved in the epigenetic programming and RNAi gene silencing in the soybean shoot apical meristem are reprogrammed for floral development following an exposure to inductive conditions.
表观遗传学在许多植物发育过程中起着至关重要的作用，包括通过基因表达的表观遗传调控来启动花的形成。介导这些修饰的组蛋白修饰蛋白涉及 SET 结构域包含的组蛋白甲基转移酶、JmjC 结构域包含的去甲基酶、乙酰转移酶和去乙酰化酶。此外，RNA 干扰（RNAi）相关基因也通过 RNA 指导的 DNA 甲基化和转录后基因沉默参与表观遗传调控。大豆是一种主要的豆科作物，需要短日照才能诱导开花。组蛋白修饰如何调节植物对外界信号的反应，从而启动开花，在很大程度上仍然未知。在这里，我们使用 RNA-seq 来研究在大豆花的起始过程中，潜在参与表观遗传编程和 RNAi 介导的基因沉默的转录物的动态变化。大豆是一个古多倍体，经历了至少两轮全基因组复制事件。我们报告说，大豆中组蛋白修饰酶和 RNA 沉默基因的扩展基因组库包括 14 个组蛋白乙酰转移酶、24 个组蛋白去乙酰化酶、47 个组蛋白甲基转移酶、15 个蛋白精氨酸甲基转移酶、24 个 JmjC 结构域包含的去甲基酶和 47 个 RNAi 相关基因。为了研究这些组蛋白修饰酶和 RNA 沉默基因在花的起始过程中的作用，我们比较了短日照处理后不同时间点的叶片和茎尖分生组织的转录动力学。我们的数据表明，在诱导条件下，大豆茎尖分生组织中通常参与表观遗传编程和 RNAi 基因沉默的基因的广泛激活被重新编程为花的发育。
