In response to biotic stress, plants synthesize defense proteins and metabolites. Volatile organic compounds (VOCs) belong to this defensive compounds group. Some esters of (Z)-3-hexenol were identified to be differentially emitted by tomato cv. Rio Grande plants upon infection with the avirulent strain of the bacterium Pseudomonas syringae DC3000 pv. tomato (Lopez-Gresa et al., 2017). Exogenous treatments with esters of (Z)-3-hexenol with acetic, propionic, isobutyric or butyric acid showed an induction of resistance against this bacterium. Particularly, treatments with (Z)-3-hexenyl butyrate (HB), resulted in
significant stomatal closure, defense genes induction and enhanced resistance to the bacteria (Lopez-Gresa et al., 2018), leading us to patent this compound due to its defensive properties (Lisón et al., 2017). We have focused on the mode of action of HB and its ability to close stomata in different plant species, resulting in HB-mediated stomatal closure in several plant species belonging to Nicotiana, Arabidopsis, Medicago, Zea and Citrus genus, or against different stresses, such as drought. Its efficacy as phyto-protector has also been tested in open field conditions and against other pathogens, such as potato and infection with the fungus Phytophthora infestans. Our results reinforce the importance of VOCs as fundamental compounds in the plant defense response, proposing HB as a new natural product for the sustainable control of stresses in agriculture.