Preliminary transcriptomic data analysis reveals key genes associated with the fruit development of Opuntia ficus-indica

The commercial prickly pear fruits have sweet juicy pulp containing hard-coated seeds, which limits the acceptability of the fruits for consumers. Two different prickly pear mutants, known as “Beer Sheeva-1” (“BS-1”) and “Revertant”, were discovered in Israel. “BS-1” fruits are parthenocarpic (seedless) and contain enlarged unfertilized ovules that develop into small, aborted seeds. Whereas some branches (about 10 %) of the “BS-1” cultivar set normal fruits, containing small ovules and viable seeds; that phenotype is called “Revertant”. We hypothesis that the parthenocarpic phenotype of “BS-1” is due to a mutation that leads to elevated levels of gibberellic acid (GA) in the ovary. This results in earlier fruit ripening, fruit morphology of longer "neck", enlarged and unfertilized ovules, smaller-less glochid and aborted seeds in “BS-1”. In this study, ovary tissues from the two mutants; i.e., BS-1 and Revertant were sequenced by high–throughput RNA–sequencing (RNA–Seq) to find differentially expressed genes. mRNA profiles of both mutants were RNA–sequenced to identify the potential candidate genes related to fruit development. A total of 7,717 differentially expressed genes (DEGs) were identified and 2178 of them were upregulated and 5539 were downregulated. Venn diagram and heat map analysis were performed to visualize the overlapping differentially expressed genes between “BS-1” and “Revertant”. Further research work in gene ontology (GO) and other bioinformatic approaches will contribute to understand the development of parthenocarpic fruit in O. ficus-indica.