Role of MicroRNAs and small RNAs in regulation of developmental processes and agronomic traits in Gossypium species

Abstract Small RNAs (sRNAs) are short, non-coding, 17–24 nucleotides long RNA molecules that play vital roles in regulating gene expression in every known organism investigated to date including cotton ( Gossypium ssp .). These tiny RNA molecules target diverse categories of genes from different bioliogical and metabolic processes and have been reported in the three domains of life. Small RNAs, including miRNAs, are involved in ovule and fiber development, biotic and abiotic stresses, fertility, and other biochemical processes in cotton species. Also, sRNAs are the critical components in RNA interference pathway. In this article, we have reviewed the research efforts related to the isolation and characterization of miRNAs using molecular and genomic approaches. The progress made in understanding the functional roles of miRNAs in regulation, alteration, and inactivation of fundamental plant processes and traits of importance in cotton are presented here.