Chitinase gene expression induced by mite-infested plant volatiles under air-flow conditions in intact lima bean plants

Abstract: Plants attacked by herbivores emit a specific blend of volatiles. When intact plants
near damaged plants perceive the blend, the plants become more defensive against herbivores. The plant-to-plant signalling mediated by plant volatiles has been reported by several research groups but the molecular responses have not been fully clarified. Lima bean plants exposed to mite-infested volatiles expressed the defence genes directly; on the other hand, corn plants exposed to worm-infested volatiles were primed for the gene induction. We observed that intact lima bean plants exposed to the volatiles emitted from mite-infested lima bean plants with an airflow equipment induced chitinase (PR-3) gene as shown in the previous report. On the other hand, the expression of the genes for lipoxygenase (LOX) and glucanase (PR-4) were not induced under this condition. From this observation, we concluded that the responses of plants against volatiles were not so assured but strongly depended on the exposure conditions.