Abstract

Drought being a production restrictive factor has become the main threat to international food security. Therefore, understanding the mechanisms underlying the drought response is one of the main scientific agenda for enhancing crop yield. Plants set out different strategies and mechanisms to respond to and tolerate drought stress. The expression of several genes is changed in different plants under drought stress that helps them to optimize their growth and development. Plant hormone abscisic acid (ABA) plays a key role in plant response and tolerance by regulating the expression of many genes under drought stress. Transcription factors being the chief regulator of gene expression play a vital role in stress response. ABA regulates the expression of the majority of the target genes through the ABA-responsive element (ABRE) binding protein/ABRE binding factor (AREB/ABF) transcription factors. Genes regulated by AREB/ABFs comprises a regulon termed as AREB/ABF regulon. In addition to this, drought-responsive genes are also regulated by ABA-independent mechanisms. In ABA-independent regulation, dehydration-responsive element-binding protein (DREB), and NAC regulons play a crucial role by regulating numerous drought-responsive genes. Apart from these key regulons, MYB/MYC, and WRKY, transcription factors family also contributes to drought response and tolerance. Our insight into the transcriptional regulation of drought is still developing. Current findings have suggested the presence of crosstalk between diverse transcription factors functioning under drought stress. In this manuscript, I have reviewed the role of different regulons functioning under drought stress and their crosstalk with each other.

Keywords: Dehydration; Abscisic acid; Transcription factors; Responsive element; Expression