Key Laboratory of Molecular Epigenetics of the Ministry of Education (MOE), Northeast Normal University, Changchun 130024, China.
Department of Biomedical Science, Sunchon National University, Suncheon 57922, Republic of Korea.
Int J Mol Sci. 2024 Aug 16;25(16):8940. doi: 10.3390/ijms25168940.
Environmental variations initiate chromatin modifications, leading to the exchange of histone subunits or the repositioning of nucleosomes. The phosphorylated histone variant H2A.X (γH2A.X) is recognized for the formation of foci that serve as established markers of DNA double-strand breaks (DSBs). Nevertheless, the precise roles of H2A.X in the cellular response to genotoxic stress and the impact of the plant hormone abscisic acid (ABA) remain incompletely understood. In this investigation, we implemented CRISPR/Cas9 technology to produce loss-of-function mutants of and in . The phenotypes of the and single mutants were nearly identical to those of the wild-type Col-0. Nevertheless, the double mutants exhibited aberrant embryonic development, increased sensitivity to DNA damage, and higher sensitivity to ABA. The RT-qPCR analysis indicates that and negatively regulate the expression of , a fundamental regulator in the ABA signaling pathway. Subsequent investigation demonstrated that participates in the genotoxic stress response by influencing the expression of DNA damage response genes, such as , , and . Our research offers new insights into the role of H2A.X in the genotoxic and ABA responses of .
环境变化引发染色质修饰，导致组蛋白亚基交换或核小体重新定位。磷酸化组蛋白变体 H2A.X（γH2A.X）因其形成焦点而被认可，这些焦点是 DNA 双链断裂（DSBs）的既定标志物。然而，H2A.X 在细胞对遗传毒性应激的反应中的精确作用以及植物激素脱落酸（ABA）的影响仍不完全清楚。在这项研究中，我们使用 CRISPR/Cas9 技术在 中产生 和 的功能丧失突变体。 和 单突变体的表型与野生型 Col-0 几乎相同。然而， 双突变体表现出异常的胚胎发育、对 DNA 损伤的敏感性增加和对 ABA 的敏感性增加。RT-qPCR 分析表明， 和 负调控 ABA 信号通路中的基本调节剂 的表达。随后的研究表明， 通过影响 DNA 损伤反应基因（如 、 和 ）的表达参与遗传毒性应激反应。我们的研究为 H2A.X 在 的遗传毒性和 ABA 反应中的作用提供了新的见解。
