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

• 成果类型: Article
• 署名作者: Huang, Shouguang; Shen, Like; Roelfsema, M. Rob G.; Becker, Dirk; Hedrich, Rainer
• 署名单位: University of Wurzburg; Nanjing Agricultural University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-10814
• DOI: 10.1126/science.adj9696
• 发表日期: 2023-12-15
• 页码: 1314-1318
• 关键词: abscisic-acid; ca2+ waves; ph; channels; GROWTH; reticulum; protein; plants

摘要

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.