Plant Genomic Network Research Team, RIKEN Plant Science Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Kanagawa, Japan.
Plant Cell Physiol. 2012 May;53(5):847-56. doi: 10.1093/pcp/pcs053. Epub 2012 Apr 13.
Changes in chromatin status are correlated with gene regulation of biological processes such as development and stress responses in plants. In this study, we focused on the transition of chromatin status toward gene repression during the process of recovery from drought stress of drought-inducible genes (RD20, RD29A and AtGOLS2) and a rehydration-inducible gene (ProDH). In response to drought, RNA polymerase II was recruited on the drought-inducible genes and rapidly disappeared after rehydration, although mRNA levels of these genes were maintained to some degree after rehydration, suggesting that the transcriptional activities of these genes were rapidly inactivated by rehydration treatment. Histone H3K9ac was enriched by drought and rapidly removed from these regions by rehydration. In contrast, histone H3K4me3 was gradually decreased by rehydration but was maintained at low levels after rehydration, suggesting that H3K4me3 functions as an epigenetic mark of stress memory. These results show that the transcriptional activity and chromatin status are rapidly changed from an active to inactive mode during the recovery process. Our results demonstrate that histone modifications are correlated with the inactivation of drought-inducible genes during the recovery process by rehydration.
染色质状态的变化与基因调控有关，如植物的发育和应激反应等生物学过程。在这项研究中，我们专注于干旱诱导基因（RD20、RD29A 和 AtGOLS2）和再水合诱导基因（ProDH）从干旱胁迫恢复过程中向基因抑制的染色质状态转变。在受到干旱胁迫时，RNA 聚合酶 II 被招募到干旱诱导基因上，在再水合后迅速消失，尽管这些基因的 mRNA 水平在再水合后在一定程度上得以维持，这表明这些基因的转录活性被再水合处理迅速失活。组蛋白 H3K9ac 在干旱胁迫下富集，并在再水合后迅速从这些区域中去除。相比之下，组蛋白 H3K4me3 逐渐减少，但在再水合后仍保持在低水平，这表明 H3K4me3 作为应激记忆的表观遗传标记。这些结果表明，在恢复过程中，转录活性和染色质状态迅速从活跃状态转变为不活跃状态。我们的结果表明，组蛋白修饰与再水合过程中干旱诱导基因的失活有关。
