Fatty Acid Amino Acid Conjugates (FACs)

In caterpillar oral secretions, fatty acid amino acid conjugates (FACs) elicit plant defense responses during herbivory. The levels of these FAC elicitors within the caterpillar appear to be controlled by two enzymes, one in the gut tissue membranes that synthesizes FACs and the other in the gut lumen that hydrolyzes them. In lepidopteran species, the fatty acid moiety of FAC originates from the caterpillar diet. FACs are essential for caterpillar performance and survival. For pest management, there is a need to understand herbivore-specific signal molecules and their identification, modes of action, and signal transduction in plants. Therefore, this chapter deals with protocols for the extraction and identification of FACs from insect oral secretions.