Plant chemical defense: monoterpenes and the growth-differentiation balance hypothesis.

Recent studies of allocation to defensive chemicals in plants have provided insights into the ecological controls over plant defensive chemicals. Both developmental and ecological studies now suggest that we can understand the factors influencing allocation to defense by examining the relative availability of resources, external needs for chemical defense, and the internal demands for growth that plants face. These studies have also shed light on one of the more popular theories in plant evolutionary ecology, the growth-differentiation balance hypothesis of plant resource allocation.