德国维尔茨堡大学Rainer Hedrich和Shouguang Huang共同合作，近期取得重要工作进展。他们研究发现，光门控通道视紫红质激发保卫细胞中质子诱导的钙释放。相关研究成果2023年12月15日在线发表于《科学》杂志上。

据介绍，尽管长期以来人们一直认为刺激诱导的胞浆pH变化与钙离子（Ca²⁺）水平的变化一致，但质子（H⁺）和Ca²⁺之间的相互依赖性仍知之甚少。

研究人员使用来自假真菌链状菌的光门控通道视紫红质HcKCR2来解决这个问题，它在植物细胞质膜上作为H⁺传导、Ca²⁺不可渗透的离子通道运行。拟南芥保护细胞中HcKCR2的光激活引起短暂的细胞质酸化，从而从内质网释放Ca²⁺。H⁺诱导的胞浆Ca²⁺信号通过激活Ca²⁺依赖性SLAC1/SLAH3阴离子通道导致膜去极化，这使人们能够远程控制气孔运动。

总之，这一研究提出了H⁺诱导的植物细胞中Ca²⁺释放机制，并建立了HcKCR2作为剖析植物细胞内pH和Ca²⁺信号传导的分子基础的工具。

附：英文原文

Title: Light-gated channelrhodopsin sparks proton-induced calcium release in guard cells

Author: Shouguang Huang, Like Shen, M. Rob G. Roelfsema, Dirk Becker, Rainer Hedrich

Issue&Volume: 2023-12-15

Abstract: Although there has been long-standing recognition that stimuli-induced cytosolic pH alterations coincide with changes in calcium ion (Ca2+) levels, the interdependence between protons (H+) and Ca2+ remains poorly understood. We addressed this topic using the light-gated channelrhodopsin HcKCR2 from the pseudofungus Hyphochytrium catenoides, which operates as a H+ conductive, Ca2+ impermeable ion channel on the plasma membrane of plant cells. Light activation of HcKCR2 in Arabidopsis guard cells evokes a transient cytoplasmic acidification that sparks Ca2+ release from the endoplasmic reticulum. A H+-induced cytosolic Ca2+ signal results in membrane depolarization through the activation of Ca2+-dependent SLAC1/SLAH3 anion channels, which enabled us to remotely control stomatal movement. Our study suggests a H+-induced Ca2+ release mechanism in plant cells and establishes HcKCR2 as a tool to dissect the molecular basis of plant intracellular pH and Ca2+ signaling.

DOI: adj9696

Source: https://www.science.org/doi/10.1126/science.adj9696