Green leaf volatile sensory calcium transduction in Arabidopsis

Abstract

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 Ca2+ concentration ([Ca2+]cyt) 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 [Ca2+]cyt in Arabidopsis. These volatiles trigger the expression of biotic and abiotic stress-responsive genes in a Ca2+-dependent manner. Tissue-specific high-resolution Ca2+ imaging and stomatal mutant analysis reveal that [Ca2+]cyt 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 [Ca2+]cyt increases and subsequent defense responses in Arabidopsis leaves.

Autonecrotic Tomato (Solanum lycopersicum L.) Line as a Potential Model for Applications in Proximal Sensing of Biotic and Abiotic Stress

“…In a visionary perspective, such type of mutants can be used as "emitters" of volatile organic compounds (VOCs) able to activate defence systems in neighbouring plants. Two recent works in different species as tea [66] and Arabidopsis [67] confirmed as the release of plants VOCs related to the herbivore-or pathogen-challenged plants was a mechanism for triggering damaged-associated biochemical pathways [68]. Genotypes such as that of the present work can be a useful tool to prove the efficacy of VOCs release from the whole plant, whether and how the VOCs are received by neighbours and if the activation of plant defence is realistic in open field conditions.…”

Phytohormones in a universe of regulatory metabolites: lessons from jasmonate

“…In theory, each of the protein–metabolite interactions has the potential to alter physiological responses through changes in gene expression. Specific examples of how small molecules may regulate transcription include the binding of β-caryophyllene to a TOPLESS-like transcriptional corepressor ( Nagashima et al 2019 ), the activation of a NIN-like protein TF by nitrate ( Liu et al 2022 ), the increase in cytosolic Ca 2+ levels by Z -3-hexenal ( Aratani et al 2023 ), the perception of β-aminobutyric acid by an aspartyl tRNA synthetase ( Luna et al 2014 ), and the modulation of reactive oxygen species homeostasis by flavonols ( Pourcel et al 2013 ; Sugimoto et al 2022 ; Daryanavard et al 2023 ) ( Fig. 3 ).…”

Epoxyalcohol Synthase Branch of Lipoxygenase Cascade

“…Additionally, unusual oxylipins, such as graminoxins [47], and complex oxylipins, such as linolipins [48], have been identified. The physiological properties of plant oxylipins have been studied, with unjustifiably great attention being paid to jasmonates [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63], traumatin, and green leaf volatiles (GLVs) [46,[64][65][66][67][68][69][70][71][72][73][74][75][76][77][78]. Much less attention has been paid to other branches of the lipoxygenase cascade, including the formation of epoxy hydroxy derivatives (epoxyalcohols) and trihydroxy derivatives (trihydroxy acids), despite the fact that these compounds are found in organisms belonging to different taxa [79][80][81][82][83][84][85][86][87][88][89][90][91]…”