Signalrezeption, Biosynthese und Ökologie Duftstoffe: Die Sprache der Pflanzen

Plants respond with coordinated actions to threats from their environment. After being attacked by a herbivorous insect, plants are able to emit a complex blend of volatiles, which attract carnivorous arthropods that reduce the number of herbivores and thus benefit the plant. By modulating the emitted volatile spectrum, plants are able to transmit information on type and intensity of their infestation to their defenders. Using either various elicitors from the saliva secretion of the herbivore or differences in the spatio-temporal pattern of wounding, the plant is able to discriminate between different herbivore species. Subsequently, a complex signalling network ensures the specific reaction to various stresses. Moreover, also plant roots are able to emit volatiles upon attack to attract the predators of root-feeding insects. New studies suggest that plants may also be able to communicate with each other: By "eavesdropping" on their damaged neighbour, plants of the same or another species can use the information on a currently increased risk of being attacked by herbivores and, as a precaution, activate its own defences. However, most of these interactions between plants and other organisms have been studied mainly under laboratory conditions and we are only starting to understand the ecology of these mechanisms in nature.