State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510642, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
BMC Plant Biol. 2021 Dec 8;21(1):580. doi: 10.1186/s12870-021-03343-5.
Leaf senescence is a highly complex and meticulous regulatory process, and the disruption of any factor involved in leaf senescence might lead to premature or delayed leaf senescence and thus result in reduced or increased crop yields. Despite sincere efforts by scientists, there remain many unsolved problems related to the regulatory factors and molecular mechanisms of leaf senescence.
This study successfully revealed that OsHXK1 was highly expressed in senescent leaves of rice. The upregulation of OsHXK1 led to premature senescence of rice leaves, a decreased level of chlorophyll, and damage to the chloroplast structure. The overexpression of OsHXK1 resulted in increases in glucose and ROS levels and produced programmed cell death (PCD) signals earlier at the booting stage. Further analysis showed that expression level of the respiratory burst oxidase homolog (RBOH) genes and OsGLO1 were increased in OsHXK1-overexpressing plants at the booting stage.
Overall, the outcomes of this study suggested that OsHXK1 could act as a positive regulator of rice leaf senescence by mediating glucose accumulation and inducing an increase in ROS.
叶片衰老过程是一个高度复杂和精细的调控过程，任何参与叶片衰老的因素的破坏都可能导致叶片过早或过迟衰老，从而导致作物产量减少或增加。尽管科学家们付出了真诚的努力，但与叶片衰老的调控因子和分子机制相关的许多问题仍然没有得到解决。
本研究成功揭示了 OsHXK1 在水稻衰老叶片中高度表达。OsHXK1 的上调导致水稻叶片过早衰老，叶绿素水平降低，叶绿体结构受损。OsHXK1 的过表达导致葡萄糖和 ROS 水平升高，并在孕穗期更早产生程序性细胞死亡 (PCD) 信号。进一步分析表明，在 OsHXK1 过表达植株中，呼吸爆发氧化酶同源物（RBOH）基因和 OsGLO1 的表达水平在孕穗期升高。
总的来说，这项研究的结果表明，OsHXK1 可以通过介导葡萄糖积累和诱导 ROS 增加来作为水稻叶片衰老的正调控因子。
