Plant MicroRNAs: Biogenesis, Functions, and Applications

MicroRNAs (miRNAs) are small 21-nt-long noncoding RNAs, involved in posttranscriptional regulation of mRNA either by direct cleavage or translational repression. They are mainly transcribed as independent transcriptional units and their expression differs during different stages of plant development. Plant miRNAs have been well studied during developmental stages and different environmental stress conditions, but their functions and regulatory networks have yet to be understood. Understanding their regulatory roles may open new avenues for crop improvement which is necessary for increased food production to feed the growing population. MicroRNA interference (miRNAi) technology provides an efficient platform for functional studies and agricultural applications.