Abstract
In response to herbivory, plants emit a specific blend of volatiles that attracts natural enemies of herbivores. The emission of the volatiles, so called herbivore-induced plant volatiles (HIPV), can be considered as one of the induced indirect defenses of plants against herbivores. In plant-pathogen interactions, brown spots are seen at infected sites on leaves by hypersensitive reaction (HR), one of the defense responses. Similar brown color can be seen in plant-spider mite interactions. For instance, either brown or white scars are observed on the lima bean leaves infested by Kanzawa spider mites. We selected two strains of the spider mites by the colors of the scar: red (to induce brown scars) and white strains. Each strain induced different blends of HIPV in lima bean plants. Based on analysis of expression of defensive genes and quantification of salicylic acid, combination of jasmonate- and salicylate-related signaling pathway partly explains the difference of HIPV from plants infested by each strain. We will discuss the differential early events in the response to damage by either strain based on the observation of Ca2+ and H2O2 by a confocal laser scanning microscopy.
