Role of small RNAs in plant stress response and their potential to improve crops

ABSTRACT Increasing plant resistance to biotic and abiotic stresses may help to address global food insecurity. We review small RNA (sRNA) research and consider the potential of sRNA-based technologies as strategies to enhance plant resistance to environmental stresses. sRNAs are essential non-coding signalling molecules 21–24 nucleotides in length that are involved in various reproduction, defence and plant development processes. sRNAs guide regulatory processes during development and environmental adaptation at the DNA or RNA level in various eukaryotic organisms. They control gene expression in eukaryotes via a process commonly termed RNA silencing. sRNAs are responsible for suppressing some pathogenic genes in eukaryotes and pests. This suppression offers the potential to protect plant growth and development through a new generation of eco-friendly RNA-based fungicides or insecticides that are specific in their target and can easily control multiple diseases simultaneously. This review focuses on sRNA production in crop species, the role of sRNAs in plant responses to a range of stresses, and their prospective applications, highlighting sRNA-based technology and applications in crops under stress. This review could serve as a reference for future researchers working on small RNAs and the roles they play in plant response to environmental stresses.