Uninfested eggplants exposed to volatiles from conspecific plants infested by omnivorous mirids exhibit jasmonic acid priming and enhanced defenses against herbivores

We studied plant–plant communication in a system that included eggplants, herbivores as prey, and the omnivorous mirid Nesidiocoris tenuis. When uninfested eggplants were exposed to volatiles from conspecific plants infested by N. tenuis adults, the amounts of jasmonic acid (JA) and salicylic acid (SA) in the exposed plants remained to be similar to those in uninfested eggplants that were exposed to volatiles from uninfested conspecific plants (control eggplants). Subsequent artificial damage to the leaves of either the exposed or control eggplants using scissors led to a significant increase in JA content in the leaves. Furthermore, following the damage, the JA content in the exposed plants was significantly higher than in the control plants. In contrast, the amount of SA in the eggplants was not affected by either exposure or subsequent artificial damage. The fecundity of Kanzawa spider mites on the leaf disks of the exposed plants was significantly lower than that on the leaf disks of the control plants. The weight gain of 2nd stadium Spodoptera litura larvae on the exposed plants was significantly lower than on the control plants. However, the survival and fecundity of N. tenuis females on both exposed and control plants were not significantly different. This study demonstrates the potential variations in the tolerance of herbivorous and omnivorous arthropods to plant defenses in response to exposure to plant volatiles.