Rice and shine: a review of miRNA-mediated responses to abiotic stress in Oryza sativa, from drought to ionizing radiation

Abstract

MicroRNAs (miRNAs) are a class of 20-24 nucleotides-long small non-coding RNAs that regulate gene expression at post-transcriptional level via directing cleavage or translational repression of complementary mRNA targets. In plants, in addition to regulating biological processes essential for proper growth and development, miRNAs are also involved in fast responses to stress. Rice (Oryza sativa) is one of the most valuable crop species, feeding over half of the global population; however, its productivity is severely affected by unfavorable environmental and climatic conditions, including drought, salinity, temperature extremes, heavy metal toxicity, and nutrient deficiencies. In this context, numerous stress-responsive miRNAs have been identified in rice, highlighting their contribution to cellular homeostasis, developmental adjustment, and stress acclimation. This review provides a comprehensive overview of miRNA biogenesis in plants and their roles in rice responses to major abiotic stresses. Special emphasis is given to miRNA-mediated regulation under genotoxic stress, particularly that induced by ionizing radiation. Overall, available evidence suggests that rice miRNA responses combine recurrent regulatory modules shared across stresses with context-dependent, stress-specific patterns, while miRNA involvement in genotoxic stress responses remains comparatively underexplored.