Connecting the dots: Epigenetics, ABA, and plant stress tolerance

Extreme changes in environmental conditions are the main cause of abiotic stress and pose a major challenge for plant survival. In addition to controlling stress-related gene expression through a signal transduction cascade, epigenetic regulation plays an important role in orchestrating rapid and precise responses of plants to dynamic changes in environmental conditions. Complex mechanisms such as DNA methylation, especially via the de novo pathway, and histone tail modifications such as methylation, acetylation, phosphorylation, ubiquitination, and SUMOylation are involved in plant stress responses. In addition, histone variants and chromatin structure contribute to the dynamic regulation of chromatin state and determine whether it remains open or closed. Here, we summarise the complex combination of epigenetic modifications and factors that together regulate plant response to climate stress, focusing on the interplay between epigenetic mechanisms and the phytohormone abscisic acid.