Why Does Herbivore Attack Reconfigure Primary Metabolism?

A plant's resistance to herbivore attack is thought to be principally determined by its secondary metabo- lism, which can be remarkably plastic and responsive to different grades and types of herbivory. Newer unbiased ''omic'' approaches, which characterize tran- scriptomic, metabolomic, and proteomic changes in herbivore-attacked plants, have laid to rest the notion that metabolism can be neatly parsed into ''secondary metabolism,'' which functions to meet environmental challenges, and ''primary metabolism,'' which sup- ports growth. The hundreds of genes regulated during the plant-herbivore or -pathogen interaction have been analyzed with microarray studies, and almost all as- pects of metabolism are represented, with a substantial