Mase Kosuke, Tsukagoshi Hironaka
Faculty of Agriculture, Meijo University, Nagoya, Japan.
Front Plant Sci. 2021 Apr 27;12:660274. doi: 10.3389/fpls.2021.660274. eCollection 2021.
Plant development under altered nutritional status and environmental conditions and during attack from invaders is highly regulated by plant hormones at the molecular level by various signaling pathways. Previously, reactive oxygen species (ROS) were believed to be harmful as they cause oxidative damage to cells; however, in the last decade, the essential role of ROS as signaling molecules regulating plant growth has been revealed. Plant roots accumulate relatively high levels of ROS, and thus, maintaining ROS homeostasis, which has been shown to regulate the balance between cell proliferation and differentiation at the root tip, is important for proper root growth. However, when the balance is disturbed, plants are unable to respond to the changes in the surrounding conditions and cannot grow and survive. Moreover, ROS control cell expansion and cell differentiation processes such as root hair formation and lateral root development. In these processes, the transcription factor-mediated gene expression network is important downstream of ROS. Although ROS can independently regulate root growth to some extent, a complex crosstalk occurs between ROS and other signaling molecules. Hormone signals are known to regulate root growth, and ROS are thought to merge with these signals. In fact, the crosstalk between ROS and these hormones has been elucidated, and the central transcription factors that act as a hub between these signals have been identified. In addition, ROS are known to act as important signaling factors in plant immune responses; however, how they also regulate plant growth is not clear. Recent studies have strongly indicated that ROS link these two events. In this review, we describe and discuss the role of ROS signaling in root development, with a particular focus on transcriptional regulation. We also summarize the crosstalk with other signals and discuss the importance of ROS as signaling molecules for plant root development.
在营养状况改变、环境条件变化以及遭受入侵者攻击时，植物的发育在分子水平上通过各种信号通路受到植物激素的高度调控。以前，活性氧（ROS）被认为是有害的，因为它们会对细胞造成氧化损伤；然而，在过去十年中，ROS作为调节植物生长的信号分子的重要作用已被揭示。植物根系积累相对较高水平的ROS，因此，维持ROS稳态对根系正常生长很重要，ROS稳态已被证明可调节根尖细胞增殖和分化之间的平衡。然而，当这种平衡被打破时，植物就无法对周围环境的变化做出反应，无法生长和存活。此外，ROS控制细胞扩展和细胞分化过程，如根毛形成和侧根发育。在这些过程中，转录因子介导的基因表达网络是ROS下游的重要环节。虽然ROS在一定程度上可以独立调节根系生长，但ROS与其他信号分子之间会发生复杂的相互作用。已知激素信号调节根系生长，并且ROS被认为与这些信号相互融合。事实上，ROS与这些激素之间的相互作用已经得到阐明，并且已经确定了在这些信号之间起枢纽作用的核心转录因子。此外，已知ROS在植物免疫反应中作为重要的信号因子发挥作用；然而，它们如何调节植物生长尚不清楚。最近的研究强烈表明，ROS将这两个事件联系起来。在这篇综述中，我们描述并讨论了ROS信号在根系发育中的作用，特别关注转录调控。我们还总结了与其他信号的相互作用，并讨论了ROS作为植物根系发育信号分子的重要性。
