Identification and improvement of isothiocyanate-based inhibitors on stomatal opening to act as drought tolerance-conferring agrochemicals

Stomatal pores in the plant epidermis open and close to regulate gas exchange between leaves and the atmosphere. To uncover and manipulate the stomatal opening pathway, we screened a chemical library and identified benzyl isothiocyanate (BITC), a Brassicales-specific metabolite, as a potent stomatal-opening inhibitor. We further developed BITC derivatives with multiple isothiocyanate groups (multi-ITCs), which demonstrated at most 66-times higher inhibitory activity on stomatal opening, as well as a longer duration of the effect and negligible toxicity.