Progress on miRNAs involved in regulating plant responses to drought and salt stresses

Drought and salt stress are common abiotic constraints that limit plant growth, development, and reproduction. In response, plants have evolved complex molecular regulatory networks enabling them to perceive external stresses acutely and initiate rapid responses. Among these, microRNAs(miRNAs) play a pivotal role. Plant miRNAs are a class of non-coding small RNAs approximately 20-24 nucleotides in length, which exert their stress-responsive functions by cleaving target genes at the post-transcriptional level or inhibiting their translation. In recent years, with the rapid development and widespread application of high-throughput sequencing technology, a large number of miRNAs involved in drought and salt stress responses have been identified, and their functions and mechanisms of action have been gradually elucidated. In this review, we systematically summarize the molecular mechanisms by which miRNAs participate in regulating plant responses to drought and salt stress, comprehensively illustrating the commonality and specificityof miRNA-mediated drought resistance and salt tolerance in plants. We also compile and discuss the miRNAs that could serve as potential targets for biological breeding. The aim is to provide a reference for in-depth research on plant miRNAs, as well as a theoretical basis and forward-looking perspectives for their practical application in the genetic improvement of drought resistance and salt tolerance in plants.