Deciphering the plant-insect phenotypic arms race

Authors: LI, XIANCHUN - University Of Arizona; Ni, Xinzhi

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 11/22/2009
Publication Date: 8/1/2010
Citation: Li, X., Ni, X. 2010. Deciphering the plant-insect phenotypic arms race. In: Liu, T.-X. and Kang, L., editors. Recent Advances in Entomological Research: From Molecular Biology to Pest Management. Beijing, China:Higher Education Press. p. 3-20.

Interpretive Summary: Plant-feeding insects and their host plants interact with each other on three different time scales. They are macro- or micro-evolutionary time scale and ecological time scale. This review focuses on the ecological time scale of molecular interactions between insects and their host plants. The interacting host plants and insect herbivores exhibit a back-and-forth attack-defense-counterdefense cycle resembling a phenotypic arms race. Phenotypic divergence in long-term is the result of repetitive short-term (or temporal) changes at cellular level in defenses and counterdefenses of individual plants and insects, which are mediated by reciprocal elicitation and regulation of gene expressions. All reciprocal regulation of gene expression, in turn, is further magnified by chemical or physical signals from the environment, the organism itself, or the interactive counterpart. All signals, irrespective of internal or external, must be received and processed at cellular level of an organism. A number of signals that trigger the reciprocal regulation of plant defense or insect counterdefense genes have been characterized. A growing number of microarray studies have defined molecular basis for plant defense and insect counterdefense interactions. This chapter comprehensively reviews the recent advancement related to the underlying molecular mechanisms of plant-insect phenotypic arms race.

Technical Abstract: Plants and herbivorous insects interact with each other on three different time scales (i.e., macro-evolutionary, micro-evolutionary, and ecological time scale). On the ecological time scale, the interacting species, both plants and insects, exhibit a back-and-forth attack-defense-counterdefense cycle, resulting in a phenotypic arms race. Such short-term changes in defenses and counterdefenses of individual plants and insects are mediated by reciprocal elicitation and regulation of gene expressions. All reciprocal regulation of gene expression, in turn, are further magnified by a chemical or physical signal, from the environment, the organism itself, or the interactive counterpart; and all signals, internal or external, must be received and processed at the cellular level. A number of signals that trigger the reciprocal regulation of plant defense or insect counterdefense genes have been characterized. A growing number of microarray studies have defined plant defense and insect counterdefense transcriptomes, i.e., the transcription rate of genes is altered by the defense-counterdefense interactions. In this book chapter, the authors review the dynamic nature of reciprocal signaling and responsive transcriptome production that underlies the plant-insect phenotypic arms race.