Methyl salicylate as an airborne signal in neighboring cowpea plants' systematic defense responses against spider mites.

Yi-Xia Wu; Ming-Xiu Liu; Wan-Ting Huang; Min-Yu Yang; Jiang-Hua Sun; Huai Liu; Ya-Ying Li

Herbivore induced plant volatiles (HIPVs) play a crucial role in regulating interactions among multiple species, including triggering defense responses in neighboring plants. In this study, cowpea plants infested with Tetranychus urticae released substantial amounts of HIPVs, particularly methyl salicylate (MeSA). To investigate the impact of exposure to HIPVs at different distances and exposure to single MeSA on plant defense against mites, a series of experiments integrating physiology, biochemistry, behavioral, and chemical analysis were conducted. Exposure of healthy cowpea plants to either HIPVs or single MeSA enhanced their direct defense responses, with effects varying according to distance and dosage. These responses included improved antioxidant enzyme activities and increased phytohormone production. Furthermore, exposure to single MeSA increased the release of volatiles, decreased the survival rate of spider mites on leaves, and reduced leaf damage. Feeding on leaves exposed to HIPVs or single MeSA also influenced detoxification and defense-related enzymatic activities in spider mites. Additionally, plants which exposed to HIPVs or single MeSA chemical attracted predatory mites. These results emphasize the distance-dependent effect of HIPVs and highlight the role of MeSA as an airborne signal that primes direct and indirect defense responses against T. urticae, providing a scientific foundation for the development of eco-friendly pest management strategies based on plant defense responses to manage spider mites.

SPIDER mites; TWO-spotted spider mite; PREDATORY mite; PLANT defenses; SALICYLIC acid

Entomologia Generalis, 2024, Vol 44, Issue 6, p1493

0171-8177

Academic Journal

10.1127/entomologia/2024/2812