Sesquiterpene sites point predators to prey
Researchers have found that maize plants respond to leaf damage caused by feeding caterpillars by emitting a blend of volatile sesquiterpenes in a spatially restricted manner that may help point beneficial predators to their prey or hosts. In maize plants infested with caterpillars, sesquiterpene volatiles are produced at high rates in damaged leaves in tissue that is apical to and on the same side of the midrib as the damage site. In undamaged leaves, or same-leaf tissue that is basal or on the other side of the midrib, sesquiterpene emissions are much lower, indicating that the signaling cascade is most probably propagated through xylem tissue. Emission patterns correlate with expression patterns of two terpene synthase genes, tsp10 and tsp23, known to be primarily responsible for sesquiterpene biosynthesis.