Biotic Stress/Applied Plant Bio
CS-8-4 - Plastid-mediated epigenetic reprogramming in plants: Investigations of stress-induced memory response
Sunday, July 15
4:18 PM - 4:38 PM
Plants produce an integrated response to environmental changes, involving pathways that elicit phytohormone, oxidative, bioenergetic and circadian clock changes to facilitate adaptive behaviors. The extent to which these responses can be channeled to a stress memory response, particularly one that is sustained trans-generationally, is not known. Our group has refined a system for investigating these questions by exploiting the effects of MSH1 suppression. MSH1 is a nuclear gene that encodes an organellar protein localized to a subgroup of plastids that we have termed ‘sensory’ plastids. MSH1 disruption within these plastids by mutation or RNAi silencing is sufficient to elicit a multi-faceted, wide-ranging stress response in the plant grown under normal environmental conditions. Subsequent generations give rise to memory of the stress, a phenotype that is heritable independent of the RNAi transgene. This non-genetic memory, heritable indefinitely, represents a novel epigenetic state that, when crossed with isogenic wildtype, produces bioenergetic changes in growth. Through the heritable and nonstochastic features of the MSH1 system, we can directly address questions of epiallelic stability, quantitative influence on plant phenotype, and behavior under conditions of heterozygosity.