Epigenetic regulation and beyond in grapevine-pathogen interactions: a biotechnological perspective

Abstract

As one of the most important crop plants worldwide, understanding the mechanisms underlying grapevine response to pathogen attacks is key to achieving a productive and sustainable viticulture. Recently, epigenetic regulation in plant immunity has gained significant traction in the scientific community, not only for its role in gene expression regulation but also for its heritability, giving it enormous biotechnological potential. Epigenetic marks have been shown to be dynamically modulated in key genomic regions upon infection, with some being maintained after such, being responsible for priming defense genes. In grapevine, however, knowledge of epigenetic mechanisms is still limited, especially regarding biotic stress responses, representing a glaring gap in knowledge in this important crop plant. Here, we report and integrate current knowledge on grapevine epigenetic regulation as well as non-epigenetic non-coding RNAs in the response to biotic stress. We also explore how epigenetic marks may be useful in grapevine breeding for resistance, considering different approaches, from uncovering and exploiting natural variation to inducing it through different means.

FIGURE 1

Main mechanisms of epigenetic regulation. A – mechanisms of DNA methylation; B – mechanisms of histone modifications; C – mechanisms of epigenetic regulatory ncRNA and their functions. Text in red represents gene families and functions already identified in grapevine. CMT – Chromomethylase; MET1 – Methyltransferase 1; DRM – Domains rearranged methyltransferase; DME – Demeter; ROS1 – Repressor of silencing 1; DML2 – Demeter‐like 2; DML3 – Demeter‐like 3; HAT – Histone Acetyltransferase; HDAC – Histone Deacetylase; HMT – histone methyltransferase; HDMT – Histone demethylase; siRNA – small interfering RNA; lncRNA – long non‐coding RNA; Ac – acetyl group; Me – methyl group. Created with BioRender.

FIGURE 2

Possible paths of introducing epigenetic marks in grapevine breeding, from harnessing natural epigenetic diversity (top panel) to inducing it (bottom panel). epiQTL – epigenetic quantitative trait locus; DMT – DNA demethylase; dCas – dead Cas.