Plant communication from an ecological perspective

Abstract

Abstract Plants respond to chemical signals (semiochemicals) that are associated with insect or pathogen attack by modifying their metabolism accordingly so that defence pathways are switched on or primed. Once the relevant semiochemicals or analogues are identified, these signals can be artificially applied to achieve similar effects. Such plant activator agrochemicals represent an entirely different approach from the one traditionally used by the agrochemical industry of deploying pesticide molecules to kill pests. These chemicals do not have direct effects on pests and diseases but upregulate plant defence genes that increase plant resistance to attack. Plant activators are compatible with integrated pest management (IPM) systems and even enhance biocontrol techniques by promoting plant attractiveness to natural enemies of plant pests, as natural enemies of pests prefer induced plants. The plant defence traits activated are often complex relying on the expression of many genes, which makes it harder for pests to adapt to them. Current practise and future prospects are reviewed in this chapter.