Abstract
Heat stress (HS) affects plant growth and development, and reduces crop yield. To combat HS, plants have evolved several sophisticated strategies. The primary HS response in plants involves the activation of heat-shock transcription factors and heat-shock proteins (HSPs). Plants also deploy more advanced epigenetic mechanisms in response to recurring HS conditions. In addition, beneficial microbes can reprogram the plant epitranscriptome to induce thermotolerance, and have the potential to improve crop yield productivity by mitigating HS-induced inhibition of growth and development. We summarize the latest advances in plant epigenetic regulation and highlight microbe-mediated thermotolerance in plants.
In nature plants encounter multiple stresses such as heat waves that negatively influence their growth and reduce productivity. Often, however, mild heat can induce tolerance to later subsequent stresses. In such circumstances, plants memorize the previous stress exposure and develop a memory termed thermopriming or thermomemory.Epigenetic modifications play a crucial role in maintaining plant HS memory, and can be essential for adaptation to intermittent HS events. In recent years epigenetic modifications such as histone methylation and small RNAs have been shown to actively participate in thermomemory in plants.Plant epigenetic modifications are not only shaped by mild stress but also by beneficial endophytic microorganisms. The use of these microbes as a tool to ensure robust responses under HS holds great potential to improve crop productivity in a sustainable manner.