Epigenetics and Acquired Tolerance to Environmental Stress

The unprecedented rate of increase in global temperatures is threatening to outpace the evolutionary adaptability of corals. With climate change endangering the very existence of coral reefs, the ability of corals to mitigate detrimental changes in their environment within their lifetime is becoming more critical than ever. A range of experiments and observations suggest that corals might be able to retain environmental memory from previous stress that provides increased resilience to recurrent events, and examples from other organisms suggest that such responses could potentially be transferred across generations. However, the underlying molecular mechanisms and the extent to which they can improve resilience and survivability in light of climate change have yet to be elucidated. This chapter provides an overview of the current knowledge on acquired tolerance to environmental stress in corals and the potential role of epigenetic mechanisms in this process. Based on the current evidence from corals and other organisms, I provide a theoretical model by which epigenetic mechanisms could confer transcriptional memory and, thus, promote acquired tolerance in these organisms.