Role of RNA interference in drought stress management: physiological, biochemical and molecular approach

Abstract

Plants frequently encounter unfavourable growth conditions due to various biotic and abiotic stress factors. Drought is a significant abiotic stress factor that negatively impacts plant growth and development resulting in reduced crop productivity. Through evolution, plants have developed dynamic mechanisms that involve complex cross-talk between different regulatory levels, providing flexibility in their response to environmental stressors. Small non-coding RNAs (ncRNAs), particularly microRNAs (miRNAs) and small interfering RNAs (siRNAs), have been discovered to play a crucial role in regulating molecular response to stress, and to be the key players in the RNA interference (RNAi) process. RNAi is a reliable strategy for precise regulation of gene expression and has emerged as a game-changer in mitigating plant responses to abiotic stress such as drought. This review summarises the role of RNAi in drought mitigation and its mechanism of action, compiling the current understanding of drought-responsive miRNAs functional at physiological, biochemical and molecular levels in major cereals. Moreover, we discuss the fine-tuning of miRNAs using the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9) system, a genome editing tool which can enhance the precision of gene expression regulation and increase plant tolerance to drought stress. These technologies have significant potential in ensuring global food security and sustainable agriculture by increasing crop yield and resilience to environmental stress.