Plants form green leaf volatiles (GLVs) almost instantly after tissue disruption caused by damages, such as herbivore damage. This rapid formation of GLVs, namely GLV-burst, is an essential factor for the plants' GLV-dependent direct and indirect defenses. However, mechanism of GLV-burst remains unknown. We observed that the formation of monogalactosyldiacylglycerol hydroperoxides (MGDG-OOHs) by Arabidopsis lipoxygenase 2 (AtLOX2) governs GLV-burst in Arabidopsis. Addition of a Ca2+ selective chelating reagent, BAPTA, during tissue disruption effectively suppressed the formation of MGDG-OOHS as well as GLV-burst. This suppression was relieved by the addition of Ca2+. Therefore, we propose that Ca2+-dependent activation of AtLOX2 facilitates GLV-burst formation as observed in leukotriene formation, which is regulated by Ca2+-dependent activation of LOXs in animal cells. (C) 2018 Elsevier Inc. All rights reserved.