Suprathreshold Water Spray Stimulus Enhances Plant Defenses against Biotic Stresses in Tomato

Area of Science:

• Plant Science
• Agricultural Science
• Entomology

Background:

• Mechanical stimuli influence plant growth, development, and defense mechanisms.
• Water spray is a common environmental mechanical stimulus impacting crops.
• Understanding its role in crop defense is crucial for agricultural applications.

Purpose of the Study:

• To investigate the effects of water spray stimulation on tomato plant growth.
• To assess tomato plant defense responses against the herbivore Helicoverpa armigera and the fungus Botrytis cinerea.
• To elucidate the underlying phytohormone and metabolic pathways involved in water spray-induced defense.

Main Methods:

• Tomato plants were subjected to suprathreshold water spray stimulus (LS).
• Plant growth and architecture were monitored.
• Phytohormone levels, chemical metabolites, and volatile organic compound (VOC) emissions were analyzed.
• Defense responses against Helicoverpa armigera and Botrytis cinerea were evaluated.

Main Results:

• LS significantly enhanced tomato plant defenses against both chewing herbivores and fungal pathogens.
• Water spray altered tomato plant architecture.
• LS treatment elevated jasmonic acid (JA) signaling pathways.
• Levels of the defensive metabolite chlorogenic acid were increased, while VOC emissions were reduced.

Conclusions:

• Water spray acts as an effective mechanical stimulus to bolster plant defenses against biotic stresses.
• The findings highlight the role of JA signaling and specific metabolites in mediating water spray-induced resistance.
• Mechanical stimulation via water spray presents a promising avenue for sustainable pest and disease management in agriculture.