Department of Biochemistry and Molecular Biology, Saitama University, Saitama, 338-8570, Japan.
Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, 753-8515, Japan.
Nat Commun. 2023 Oct 17;14(1):6236. doi: 10.1038/s41467-023-41589-9.
Plants perceive volatile organic compounds (VOCs) released by mechanically- or herbivore-damaged neighboring plants and induce various defense responses. Such interplant communication protects plants from environmental threats. However, the spatiotemporal dynamics of VOC sensory transduction in plants remain largely unknown. Using a wide-field real-time imaging method, we visualize an increase in cytosolic Ca concentration ([Ca]) in Arabidopsis leaves following exposure to VOCs emitted by injured plants. We identify two green leaf volatiles (GLVs), (Z)-3-hexenal (Z-3-HAL) and (E)-2-hexenal (E-2-HAL), which increase [Ca] in Arabidopsis. These volatiles trigger the expression of biotic and abiotic stress-responsive genes in a Ca-dependent manner. Tissue-specific high-resolution Ca imaging and stomatal mutant analysis reveal that [Ca] increases instantly in guard cells and subsequently in mesophyll cells upon Z-3-HAL exposure. These results suggest that GLVs in the atmosphere are rapidly taken up by the inner tissues via stomata, leading to [Ca] increases and subsequent defense responses in Arabidopsis leaves.
植物能够感知到邻近的机械损伤或食草动物损伤的植物释放的挥发性有机化合物 (VOCs)，并诱导各种防御反应。这种植物间的通讯可以保护植物免受环境威胁。然而，植物中 VOC 感觉转导的时空动态在很大程度上仍然未知。我们使用宽场实时成像方法，可视化了拟南芥叶片在暴露于受伤植物释放的 VOC 后细胞溶质 Ca 浓度 ([Ca]) 的增加。我们鉴定出两种绿叶挥发物 (GLVs)，(Z)-3-己烯醛 (Z-3-HAL) 和 (E)-2-己烯醛 (E-2-HAL)，它们增加了拟南芥中的 [Ca]。这些挥发物以 Ca 依赖性方式触发生物和非生物胁迫响应基因的表达。组织特异性高分辨率 Ca 成像和气孔突变体分析表明，Z-3-HAL 暴露后，[Ca] 在保卫细胞中瞬间增加，随后在叶肉细胞中增加。这些结果表明，大气中的 GLVs 通过气孔迅速被内部组织吸收，导致拟南芥叶片中的 [Ca] 增加和随后的防御反应。
