Uptake and Conversion of Volatile Compounds in Plant–Plant Communication

Volatile organic compounds emitted from plants have an important role in communication between plants and other organisms (e.g. plant–pollinator, plant–herbivore and plant–carnivore communication). Recent studies have revealed a novel mechanism of volatile-mediated plant–plant communication. Here, plants take up volatiles through the stomata and by adsorption on the leaf surface. The volatiles are then processed within leaf tissues. Reduction and esterification of compounds increase their volatility, and the converted volatiles are emitted again into the air. Volatiles taken up by a plant also undergo glycosylation and glutathionylation, resulting in their conversion to non-volatile compounds that have ecological functions. For example, one of the glycosylated compounds, (Z)-3-hexenyl vicianoside, functions in plant defences against insect herbivory. Conversion to non-volatile forms would enable uninjured plants to be more defended against herbivores moving from neighbouring herbivore-infested plants. Uptake and conversion of volatile compounds in plants is discussed in this chapter.