Drought stress and chromatin: An epigenetic perspective

In the current scenario of growing world population, industrialization, and global warming, tackling drought stress in its entirety is a focus issue for plant scientists to devise strategies favoring plant growth under uncertain water regimes. The onset of stress leads to epigenetic alterations in the cell leading to a more closed/condensed state (heterochromatin) and repressed transcription. Such a stress response, often reversible is stored in the “stress memory�? of the plant, and once favorable conditions return the cell again acquires an open/decondensed state and becomes transcriptionally active (euchromatin). In this chapter, we aim to enlighten readers with a comprehensive overview of how onset of drought stress affects changes in chromatin gene expression and how the prevailing molecular and physiological strategies can be entailed for chromatin-mediated drought tolerance in plants. Moreover, we apprise readers of the adaptive significance of transgenerational inheritance of DNA methylation patterns in plant drought tolerance. Lastly, we discuss future strategies for sustainable drought stress tolerance through transcriptional control of dehydration stress memory genes regulating dynamic chromatin structure and stability.