MicroRNA: One Of The Stress Fighters Plays Crucial Role In Resilience Of Rice To Changing Climatic Conditions

This century is presenting global climate change with significant alterations in environmental conditions, which might affect the growth, development, and survival of several organisms. In turn, such changes affect the availability of food, feed, and fodder for the creatures on the earth. Recurring environmental stresses like heat, drought, cold, flooding, etc. might cause considerable yield losses, challenges to crop husbandry, and concerns for sustainable food security. Modulation in gene expression under stressful conditions is one of the molecular strategies adopted by plants to cope with environmental stresses. MicroRNAs (miRNAs) are known to play important roles in controlling gene expression either through translational repression or due to cleavage of mRNA. Moreover, miRNAs are emerging as newer candidates for modulating developmental processes including productivity/yield as well as responses to stress in plants. Often the targets of miRNAs are transcription factors and the genes associated with stress responses affecting adaptive potential of the plant. A combination of miRNAs (miR160-ARF, miR159-MYB, and miR169-NFYA) was reported to be involved in regulating gene expression under drought in plants. These drought-responsive miRNAs were shown to affect physiological, biochemical, and molecular responses and serving as candidates for genetic manipulation of crop plants for enhanced stress resilience. This review provides insights on miRNA as a stress fighter that plays an important role in resilience to environmental stresses in plants, particularly in rice. miRNA has been reported to control crucial biological processes like respiration, photosynthesis, signalling pathways, senescence, etc., particularly under stressful conditions. Some of the limitations as well as future perspectives of utilizing miRNA-based strategies for improvement have been discussed. These might help understanding the functions of miRNAs, as one of the important components of the gene regulatory network, which will facilitate genetic improvement of crops for multiple stresses and yielding potential.