Metabolomic and transcriptomic analyses provide insights into the role of MiMYB114 and MiMYC2 in the MeJA-induced regulatory network for mango pericarp coloration

Abstract

The color of mango fruit peel is a critical factor influencing consumer preference and market value. MeJA can enhance mango pericarp coloration, but its effects on different pigments accumulation and the underlying molecular mechanisms remain unclear. In this study, exogenous treatment of 4 mmol/L MeJA enhances the red and yellow pigments in the pericarp of mango cultivar ‘Guifei’. Metabolomic analysis revealed that MeJA significantly increases anthocyanin and carotenoid accumulation while accelerating chlorophyll degradation. Transcriptomic analysis indicated that MeJA promotes the expression of genes involved in anthocyanin biosynthesis (e.g., MiPAL, MiC4H, MiF3H, and MiUFGT), chlorophyll degradation (MiSGRs, MiPPHs, MiPAO, and MiRCCRs), and carotenoid biosynthesis (MiPSY, MiLCYB, MiBCH, and MiZEP). Furthermore, the transcription factors (MYBs, AP2-ERFs, bHLHs, WRKYs, and TIFYs) were induced by MeJA. Of these, transient expression assays suggested that MiMYB114 mediates anthocyanin accumulation by enhancing the expression of MiF3H and MiUFGT, and the bHLH transcription factor MiMYC2 regulates chlorophyll degradation and carotenoid biosynthesis by promoting the expression of MiSGR, MiRCCR, MiPSY, and MiBCH. Our results provide new insights into the regulatory roles of MeJA treatment in mango pericarp coloration.