Department of Biological Sciences, Tokyo Metropolitan University, Minami-osawa, Hachioji, Tokyo, Japan.
Kihara Institute for Biological Research, Yokohama City University, Maiokacho, Totsuka-ku, Yokohama, Kanagawa, Japan.
Plant J. 2021 Nov;108(4):1097-1115. doi: 10.1111/tpj.15497. Epub 2021 Oct 8.
Reactive oxygen species (ROS) play essential roles in plant development and environmental stress responses. In this study, ROS dynamics, the glutathione redox status, the expression and subcellular localization of glutathione peroxidases (GPXs), and the effects of inhibitors of ROS-mediated metabolism were investigated along with fertilization and early zygotic embryogenesis in rice (Oryza sativa). Zygotes and early embryos exhibited developmental arrest upon inhibition of ROS production. Egg cells accumulated high ROS levels, and, after fertilization, intracellular ROS levels progressively declined in zygotes in which de novo expression of GPX1 and 3 was observed through upregulation of the genes. In addition to inhibition of GPX activity, depletion of glutathione impeded early embryonic development and led to failure of the zygote to appropriately decrease H O levels. Moreover, through monitoring of the glutathione redox status, the developing zygotes exhibited a progressive glutathione oxidation, which became extremely delayed under inhibited GPX activity. Our results provide insights into the importance of ROS dynamics, GPX antioxidant activity, and glutathione redox metabolism during zygotic/embryonic development.
活性氧（ROS）在植物发育和环境胁迫响应中发挥着重要作用。在这项研究中，我们研究了 ROS 动力学、谷胱甘肽氧化还原状态、谷胱甘肽过氧化物酶（GPXs）的表达和亚细胞定位，以及 ROS 介导的代谢抑制剂对水稻受精和早期合子胚胎发生的影响。ROS 产生受到抑制后，合子和早期胚胎发育停滞。卵细胞积累了高水平的 ROS，受精后，新合成的 GPX1 和 3 通过基因的上调表达，在合子中观察到细胞内 ROS 水平逐渐下降。除了抑制 GPX 活性外，谷胱甘肽的耗竭也阻碍了早期胚胎的发育，并导致合子不能适当降低 H2O2 水平。此外，通过监测谷胱甘肽氧化还原状态，发育中的合子表现出谷胱甘肽逐渐氧化，而在抑制 GPX 活性下，这一过程变得极其延迟。我们的研究结果为 ROS 动力学、GPX 抗氧化活性和谷胱甘肽氧化还原代谢在合子/胚胎发育过程中的重要性提供了新的见解。
