p. 50718 Biotic Interactions
- Lincoln Taiz, Lincoln TaizUniversity of California, Santa Cruz
- Eduardo Zeiger, Eduardo ZeigerUniversity of California, Los Angeles
- Ian Max MøllerIan Max MøllerAarhus University, Denmark
- , and Angus MurphyAngus MurphyUniversity of Maryland
Abstract
This chapter addresses biotic interactions, starting with examples of beneficial associations between plants and microorganisms. Such mutually beneficial biotic interactions are termed mutualisms. The chapter then considers various types of harmful interactions between plants, herbivores, and pathogens and the defensive mechanisms used by plants against them. It surveys the wide range of constitutive and inducible defenses that plants deploy to fend off insect herbivores. Constitutive defenses are always present, whereas inducible defenses are triggered in response to attack. Unlike constitutive defenses, inducible defenses require specific detection systems and signal transduction pathways that can sense the presence of an herbivore or pathogen and alter gene expression and metabolism accordingly. Finally, the chapter notes the important roles that volatile organic compounds play in repelling herbivores, attracting insect predators, and acting as distress signals between different parts of plants and between neighboring plants.
