Role of miRNAs in Fruit Ripening, Shelf Life, Biofortification and Allergenicity: An Update

Postharvest losses of perishable fruits are mainly due to over-ripening, which significantly affects farmers. Nutrient-related and allergenicity-related miRNAs and their gene regulation machinery constitute novel platforms for improving the fruit nutritional status and reducing allergenicity, respectively. The development of modern technologies, such as high-throughput sequencing and degradome sequencing of small RNAs, has enabled the identification of several conserved and non-conserved miRNAs in different fruits. Several novel miRNAs and their targets identified through different studies have revealed that these miRNAs play key roles in the regulation of genes involved in different metabolic pathways. These observations and findings help in understanding the target genes of different miRNAs that are known to regulate fruit development, ripening, and shelf life, as well as the enhancement of mineral nutrients and vitamins, and the suppression of allergen effects in major edible fruit crops. The biofortification of different fruits offers a sustainable solution for delivering nutrient-rich fruit in the human diet. The application of a recent CRISPR/Cas9 based genome editing tool could be a better option for producing low allergenic fruit through the downregulation of specific genes. This review discusses about the identification and validation of different classes of miRNAs involved in the regulation of fruit development and ripening, shelf life, biofortification and allergenicity.