Elicitor

In plant biology, elicitors are extrinsic or foreign molecules often associated with plant pests, diseases or synergistic organisms. Elicitor molecules can attach to special receptor proteins located on plant cell membranes. These receptors are able to recognize the molecular pattern of elicitors and trigger intracellular defence signalling via the octadecanoid pathway. This response results in the enhanced synthesis of metabolites which reduce damage and increase resistance to pest, disease or environmental stress. This is an immune response called pattern triggered immunity (PTI).

PTI is effective against necrotrophic microorganisms.

An example is chitosan which is found in insects, fungi and the shells of crustaceans. Chitosan is used in agriculture as a natural biocontrol agent, to improve plant health and increase crop yields.