Key message

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.

Abstract

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.

中文翻译：

---

OsRbohB 介导的 ROS 产生在水稻的干旱胁迫耐受性中起关键作用

关键信息

我们发现水稻 NADPH 氧化酶基因OsRbohB有助于耐旱，其功能涉及 OsRbohB 介导的 ROS 产生和 ABA 信号传导的相互作用。

抽象的

质膜 NADPH 氧化酶，也称为呼吸爆发氧化酶同源物，是植物在正常和胁迫条件下产生 ROS 的关键。然而，它们在水稻发育和抗逆性中的作用仍在研究中。在这里，我们发现水稻 NADPH 氧化酶基因OsRbohB，也称为OsNOX1，在整个发育阶段检查的所有组织中都有表达，在叶片中具有更高的转录本。OsRbohB的转录表达也受到脱水、盐和几种植物激素处理的强烈刺激。与宽型和过表达 OsRbohB的转基因植物相比，osrbohB是OsRbohB的 Tos17 插入敲除突变体，显示出较低的 ROS 产生、脱落酸 (ABA) 含量和一系列应激相关基因的转录本。osrbohB突变体还表现出较低的种子发芽率、器官大小和千粒重，但较高的气孔孔径和对干旱的敏感性。此外，在正常生长和干旱条件下， osrbohB植物中的许多参与植物发育、应激反应、转录调控，特别是 ABA 信号传导的基因都有差异表达。所有这些结果表明OsRbohB在水稻耐旱性中的作用可能是通过 OsRbohB 介导的 ROS 产生和 ABA 信号传导的相互作用来实现的。