Epigenetic reponses and memories to (a)biotic stresses in grapevine

Abstract

Epigenetics corresponds to the complement of genetic information carried in chromatin beyond the DNA sequence. It includes posttranslational modifications of histones, DNA methylation and small RNAs, all involved in the control of gene expression and transposon mobility. Studies in Arabidopsis, tomato and many other plants, have demonstrated the relevance of epigenetic mechanisms in the control of development, their impact on agronomic traits and on genome stability, as well as their role in the responses of plants to various stresses, and to the memory stresses. However, most epigenetic studies so far were performed on annual plants, whereas epigenetic studies in perennials are still in their infancy. As a woody perennial, grafted and clonally propagated pant, grapevine presents unique features that make it an interesting model for epigenetic studies.

In this context we have investigated the role of epigenetic mechanisms in grapevine berries and plants, focusing on DNA methylation. We have shown tissue specific modifications of DNA methylation during berry development and ripening.  Additional works are analyzing the possible roles of DNA methylation in the epigenetic memory of stresses considering both annual and trans annual priming of different stresses, such as drought stress, carbon limitation and the esca disease. To this end we are developing integrative approaches that extend from the analysis of epigenetic landscapes, transcriptomic and metabolic profiles to plant phenotypes.

Our current results indicate that the leaf methylome of grapevine is highly dynamic in response to stresses, and that stress priming influence the response of grapevine to subsequent stresses. In addition, we demonstrate a transannual memory of stresses, even after two years of stress recovery, consistent with a long-term epigenetic memory of stresses. However, this trans annual memory may depend on the type, intensity frequency and length of stresses. Current investigation are focusing on the inheritance through clonal plant propagation of stress induced DNA methylation pattern and of their phenotypical consequences. We expect that these approaches in combination will allow determining the part of the epigenetic information that is inherited from parental plants from the one acquired in a specific environment, and evaluating consequences on grapevine plants.