Sequence variation in genes encoding miRNAs/targets and other related approaches for possible use in crop improvement

Abstract

MicroRNAs (miRNAs) are small non-coding RNAs (ncRNAs), which are involved in regulation of gene expression in almost all plant and animal systems. In crop plants, a large number of miRNAs are now known, which regulate expression of genes controlling a variety of traits including yield and tolerance to biotic and abiotic stresses. Like protein-coding genes, miRNA genes (MIRs) and their products (including pri-miRNAs, pre-miRNAs or miRNAs themselves) also exhibit sequence variation. This variation affects the corresponding miRNAs in a variety of ways including their own transcription, maturation and target specificity. In this review, we summarize the available information on markers based on sequence variations in MIRs and the corresponding target genes. The association of these markers with agronomic traits of value and their possible use in crop improvement is also discussed using suitable examples.