State Key Laboratory of Crop Stress Biology in Arid Area/College of Life Sciences, Northwest A&F University, Yangling, 712100, Shanxi, China.
College of Science, Northwest A&F University, Yangling, 712100, Shanxi, China.
Plant Cell Rep. 2020 Dec;39(12):1767-1784. doi: 10.1007/s00299-020-02603-2. Epub 2020 Sep 26.
We found that a rice NADPH oxidase gene OsRbohB contributes drought tolerance and its functions are involved in the interaction of the OsRbohB-mediated ROS production and ABA signaling. The plasma membrane NADPH oxidases, also known as respiratory burst oxidase homologs, are the key producers of ROS under both normal and stress conditions in plants. However, their functions in rice development and stress tolerance are still under investigation. Here, we found that a rice NADPH oxidase gene OsRbohB, also named OsNOX1, is expressed in all tissues examined throughout the development stages with higher transcripts in leaves. The transcriptional expression of OsRbohB is also strongly stimulated by dehydration, salt and several phytohormonal treatments. Compared with wide-type and the OsRbohB-overexpressing transgenic plants, osrbohB, a Tos17 insertion knockout mutant of OsRbohB, shows lower ROS production, abscisic acid (ABA) content and transcripts of a series of stress-related genes. The osrbohB mutant also exhibits lower seed germination rate, organ size and thousand seed weight, but higher stomatal aperture and sensitivity to drought. Moreover, a number of genes involved in plant development, stress response, transcriptional regulation, and particularly ABA signaling are differentially expressed in osrbohB plants under both normal growth and drought conditions. All these results suggest the roles of OsRbohB in drought tolerance of rice, which probably performed through the interaction of the OsRbohB-mediated ROS production and ABA signaling.
我们发现，水稻 NADPH 氧化酶基因 OsRbohB 有助于耐旱性，其功能涉及 OsRbohB 介导的 ROS 产生和 ABA 信号的相互作用。质膜 NADPH 氧化酶，也称为呼吸爆发氧化酶同源物，是植物在正常和应激条件下 ROS 的主要产生者。然而，它们在水稻发育和耐胁迫中的功能仍在研究中。在这里，我们发现，水稻 NADPH 氧化酶基因 OsRbohB，也称为 OsNOX1，在整个发育阶段的所有组织中表达，在叶片中表达更高的转录本。OsRbohB 的转录表达也强烈受到脱水、盐和几种植物激素处理的刺激。与野生型和 OsRbohB 过表达转基因植物相比，OsRbohB 的 Tos17 插入敲除突变体 osrbohB 表现出较低的 ROS 产生、脱落酸 (ABA) 含量和一系列与胁迫相关基因的转录本。osrbohB 突变体还表现出较低的种子发芽率、器官大小和千粒重，但气孔孔径较大，对干旱敏感。此外，在正常生长和干旱条件下，osrbohB 植物中许多参与植物发育、应激反应、转录调节的基因，特别是 ABA 信号的基因表达存在差异。所有这些结果表明 OsRbohB 在水稻耐旱性中的作用，这可能是通过 OsRbohB 介导的 ROS 产生和 ABA 信号的相互作用来实现的。
