A small peptide modulates stomatal control via abscisic acid in long-distance signalling

First author: Fuminori Takahashi; Affiliations: RIKEN Center for Sustainable Resource Science (日本理化研究所可持续资源科学中心): Tsukuba, Japan

Corresponding author: Kazuo Shinozaki 

Mammalian peptide hormones propagate extracellular stimuli from sensing tissues to appropriate targets to achieve optimal growth maintenance. In land plants, root-to-shoot signalling is important to prevent water loss by transpiration and to adapt to water-deficient conditions. The phytohormone abscisic acid has a role in the regulation of stomatal movement to prevent water loss. However, no mobile signalling molecules have yet been identified that can trigger abscisic acid accumulation in leaves. Here we show that the CLAVATA3/EMBRYO-SURROUNDING REGION-RELATED 25 (CLE25) peptide transmits water-deficiency signals through vascular tissues in Arabidopsis, and affects abscisic acid biosynthesis and stomatal control of transpiration in association with BARELY ANY MERISTEM (BAM) receptors in leaves. The CLE25 gene is expressed in vascular tissues and enhanced in roots in response to dehydration stress. The root-derived CLE25 peptide moves from the roots to the leaves, where it induces stomatal closure by modulating abscisic acid accumulation and thereby enhances resistance to dehydration stress. BAM receptors are required for the CLE25 peptide-induced dehydration stress response in leaves, and the CLE25–BAM module therefore probably functions as one of the signalling molecules for long-distance signalling in the dehydration response.

哺乳动物多肽激素通过将组织感知到的外界环境刺激传递到合适的部位以维持生物能够最大化的生长。在陆地植物中，由地下部分到地上部分的信号转导对于植物通过蒸腾作用防止水分丢失以适应水缺乏条件是非常重要的。植物激素脱落酸在调节植物的气孔运动以防止水分丢失方面发挥重要作用。然而，目前为止还没有鉴定到能够诱导叶片中脱落酸积累的来自根迁移上来的信号分子。本文中，作者在拟南芥中鉴定到了一个CLE25多肽，其能够将水分缺失的信号通过维管组织转移到地上部分，并影响叶片中脱落酸的生物合成以及与BAM受体相关的植物蒸腾作用的气孔运动。CLE25基因在维管组织中表达，并且在根中的表达会响应于脱水胁迫而增强。源自于根中的CLE25多肽会从根中转移到叶片中，进而通过调节脱落酸的积累诱导气孔的关闭，从而增强植株对脱水胁迫的抗性。BAM受体对于由CLE25多肽在叶片中诱导的脱水胁迫抗性是必要的，因此CLE25-BAM模块作为长距离信号转导的信号分子在植物应对脱水胁迫的发挥作用。

通讯：Kazuo Shinozaki (http://www.csrs.riken.jp/en/labs/gdrg/)

个人简介：1997年，名古屋大学，分子生物学博士。

研究方向：植物应对环境胁迫的调控因子及信号转导因子；利用反向遗传学方法研究参与植物产量的相关基因；培育具有环境胁迫抗性的小麦和水稻；开发针对突变基因功能分析的表型组分析平台。

doi: https://doi.org/10.1038/s41586-018-0009-2

Journal: Nature

Published date: 04 April, 2018