Novel microRNAs regulating ripening-associated processes in banana fruit

MicroRNAs (miRNAs) modulate gene expression and regulate various physiological and developmental processes in plants. During fruit ripening phase, several physiological and biochemical variations take place resulting changes in colour and texture, softening and production of aroma volatiles. A number of pathways leading to cell wall hydrolysis, ethylene signaling, biosynthesis of fatty acids, esters and a number of secondary plant products play important role during fruit ripening. However, detailed analysis of various processes regulated by miRNAs has not been studied in detailed in a number of fruits. In this study, we sequenced small RNA libraries from ripe and un-ripe fruit of Banana ( Musa acuminata ), an important and staple food crop, to identify miRNAs regulating fruit ripening. Our analysis identified a number of novel miRNAs which are differentially expressed during fruit ripening. These novel miRNAs were analyzed for their precursors, chromosome localization and targets. Some of these miRNAs were identified to target genes involved in miRNA biogenesis, fruit softening and aroma biosynthesis. This study advances our knowledges in the area of fruit ripening process regulated by miRNAs.