Suprathreshold\nWater Spray Stimulus Enhances Plant\nDefenses against Biotic Stresses in Tomato

Mechanical stimuli can affect plant growth, development,\nand defenses.\nThe role of water spray stimulation, as a prevalent mechanical stimulus\nin the environment, in crop growth and defense cannot be overlooked.\nIn this study, the effects of water spray on tomato plant growth and\ndefense against the chewing herbivore Helicoverpa armigera and necrotrophic fungus Botrytis cinerea were investigated. Suprathreshold water spray stimulus (LS) was\nfound to enhance tomato plant defenses against pests and pathogens\nwhile concurrently modifying plant architecture. The results of the\nphytohormone and chemical metabolite analysis revealed that LS improved\nthe plant defense response via jasmonic acid (JA) signaling. LS significantly\nelevated the level of a pivotal defensive metabolite, chlorogenic\nacid, and reduced the emissions of volatile organic compounds (VOCs)\nfrom tomato plants, thereby defending against pest and pathogen attacks.\nThe most obvious finding to emerge from this study is that LS enhances\ntomato plant defenses against biotic stresses, which will pave the\nway for further work on the application of mechanical stimuli for\npest management.