Switching on plant genes by external chemical signals

During the past decade there has been rapidly increasing interest in the ro le of plant volatiles in insect-plant interactions and the induction of pla nt defence systems by both pathogens and herbivores. Scientists are strivin g to link the proximate studies elucidating pathways end genes with the ult imate adaptive studies that attempt to explain their ecological role. Howev er, we still do not know whether plants 'talk' to one another by employing 'phytopheromones'.