The singer-song-writer Paul Simon sang about the '50 ways to leave your lover'; plants have at least as many ways of coping with their insect herbivores. Recent research has elucidated the mechanisms of direct and indirect plant defenses, and has provided the first proof of a protective function for indirect defenses in nature. Insect attack elicits a large transcriptional reorganization that differs from that elicited by mechanical wounding. Elicitors in herbivore oral secretions can account for herbivore-specific responses. Patterns of transcriptional changes point to the existence of central herbivore-activated regulators of metabolism.