The effect of stress on genome regulation and structure

Abstract

• Background: Stresses exert evolutionary pressures on all organisms, which have developed sophisticated responses to cope and survive. These responses involve cellular physiology, gene regulation and genome remodelling. • Scope: In this review, the effects of stress on genomes and the connected responses are considered. Recent developments in our understanding of epigenetic genome regulation, including the role of RNA interference (RNAi), suggest a function for this in stress initiation and response. We review our knowledge of how different stresses, tissue culture, pathogen attack, abiotic stress, and hybridization, affect genomes. Using allopolyploid hybridization as an example, we examine mechanisms that may mediate genomic responses, focusing on RNAi-mediated perturbations. • Conclusions: A common response to stresses may be the relaxation of epigenetic regulation, leading to activation of suppressed sequences and secondary effects as regulatory systems attempt to re-establish genomic order. © 2004 Annals of Botany Company.