Molecular and epigenetic basis of heat stress responses and acclimatization in plants

Plants have developed highly sophisticated mechanisms to regulate stress responses. Plants change and reorient their transcriptome and proteome while dealing with the heat stress within minutes of being exposed to heat. The change in transcriptome/proteome is primarily driven by epigenetic modifications. The epigenetic modification also plays a huge role in acclimatizing the plants for heat stress and therefore, plays a significant role in faster and swift response in terms of expression of heat shock proteins and maintaining the structural and physiological stability. Epigenetic modifications such as DNA methylation and histone modifications like acetylation, phosphorylation, methylation play a central role in regulating transcription and translation. The present review will underline and discuss the role of different epigenetic modification in heat stress responses of plants and the acclimatization of plants to re-exposure to heat stress. Although the initial mechanism of plant's responses to many abiotic stresses is similar, however, recent understanding has suggested heat-stress-specific epigenetic modifications in plants. The present review will also give a comprehensive detail of heat-stress-specific responses and underlying mechanisms in plants.