Epigenetic changes and photosynthetic plasticity in response to environment

Abstract Without photosynthesis, life on earth as we know it would be impossible. Advances in our understanding of how light harvesting and carbon fixation work have traditionally been driven by biochemical and molecular approaches with the goal of increasing crop yield. However, environmental challenges are putting the survival of many plants at risk due to photosynthetic inbalance. Epigenetic regulation has only recently been recognized as an important player in the response to changes in key environmental conditions such as light, temperature and drought, and while there has been scattered research on the topic, it has not yet been collated into a review. Here we focus on epigenetics’ affect on photosynthesis-related carbon fixation pathways and identify important directions for future research. For instance, during the perception of light, epigenetic regulation mediates a complex and flexible series of events, including histone acetylation and DNA demethylation, to promote expression of several genes involved in carbon fixation, such as RuBisCO and PEPC in C 3 and C 4 plants, respectively. On the other hand, the crucial role of deacetylases of histones HD1 and HDA15 and the possible participation of miRNAs during light/dark signaling and light harvesting, respectively, reveal an unexplored connection between light signaling and epigenetic regulation during photosynthesis. In the present review, we highlight how euchromatin configuration helps in the acquisition of drought tolerance and efficient stomata conductance. Therefore, we suggest that several drought-sensitive crops could be improved with the use of miRNA to optimize photosynthetic stomata conductance and gas exchange.