Transcriptome and proteome analysis of the fig (Ficus carica L.) cultivar Orphan and its mutant Hongyan based on the fruit peel colour in South China

The external fruit colour is an important parameter of the fig fruit quality. Fig anthocyanin content is critical for the peel colour. The peel of mature fruits of the fig cultivar Orphan and its red peel bud mutant Hongyan were separated for a transcriptomic and proteomic analysis. A total of 162 different abundance proteins (DAPs) and 5 015 differentially expressed genes (DEGs) were identified. The correlation analysis revealed that only two and 15 genes were downregulated and upregulated, respectively, at both the transcriptome and proteome levels. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that the enrichment pathways including Tropane, piperidine and pyridine alkaloid biosynthesis, phenylalanine metabolism and isoquinoline alkaloid biosynthesis for DEGs, and protein processing in the endoplasmic reticulum and flavonoid biosynthesis may contribute to the mutant color phenotype. Our results provide transcriptomic and proteomic information for two fig cultivars and may help to clarify the potential mechanisms of fig colouration.