International Research Centre for Environmental Membrane Biology, Foshan University, Foshan, China.
Key Laboratory of Horticultural Plant Biology (MOE), Huazhong Agricultural University, Wuhan, China.
Plant Cell Environ. 2020 Dec;43(12):2957-2968. doi: 10.1111/pce.13907. Epub 2020 Oct 26.
Soil salinization is a major threat to global food security and the biodiversity of natural ecosystems. To adapt to salt stress, plants rely on ROS-mediated signalling networks that operate upstream of a broad array of physiological and genetic processes. A key player in ROS signalling is NADPH oxidase, a plasma-membrane-bound enzyme encoded by RBOH genes. In this study, we have conducted a comprehensive bioinformatic analysis of over 50 halophytic and glycophytic species to link the difference in the kinetics of ROS signalling between contrasting species with the abundance and/or structure of NADPH oxidases. The RBOH proteins were predicted in all the tested plant lineages except some algae species from the Rhodophyta, Chlorophyta and Streptophyta. Within the glycophytic group, the number of RBOH copies correlated negatively with salinity stress tolerance, suggesting that a reduction in the number of RBOH isoforms may be potentially related to the evolution of plant salinity tolerance. While halophytes did not develop unique protein families during evolution, they evolved additional phosphorylation target sites at the N-termini of NADPH oxidases, potentially modulating enzyme activity and allowing more control over their function, resulting in more efficient ROS signalling and adaptation to saline conditions.
土壤盐渍化是全球粮食安全和自然生态系统生物多样性的主要威胁。为了适应盐胁迫，植物依赖于 ROS 介导的信号网络，该网络在广泛的生理和遗传过程的上游运作。ROS 信号转导中的一个关键参与者是 NADPH 氧化酶，它是一种由 RBOH 基因编码的质膜结合酶。在这项研究中，我们对 50 多种盐生植物和糖生植物进行了全面的生物信息学分析，将不同物种之间 ROS 信号转导动力学的差异与 NADPH 氧化酶的丰度和/或结构联系起来。除了一些来自红藻门、绿藻门和木贼门的藻类物种外，所有测试的植物谱系都预测到了 RBOH 蛋白。在糖生植物组中，RBOH 拷贝数与盐胁迫耐受性呈负相关，这表明 RBOH 同工型数量的减少可能与植物耐盐性的进化有关。虽然盐生植物在进化过程中没有形成独特的蛋白质家族，但它们在 NADPH 氧化酶的 N 端进化出了额外的磷酸化靶位，这可能调节了酶活性，并允许对其功能进行更多的控制，从而产生更有效的 ROS 信号转导，并适应盐度条件。
