Elucidating the Role of MdERF2 in Apple Fruit Quality Formation Through Transcriptome Profiling

The Ethylene-Responsive Factor 2 (ERF2) plays a critical regulatory role in multiple physiological processes associated with apple development and maturation. Based on the analysis of the apple MdERF2 gene and the basic structural and characteristics of the amino acids it encodes, this study constructed MdERF2 overexpression plasmids, genetically transformed apple callus, and investigated the effects of MdERF2 overexpression on differentially expressed genes across metabolic pathways through transcriptome sequencing. The results revealed that MdERF2 modulates enzymatic browning by regulating MdPAL1 expression, mediates tissue resistance by influencing MdC4H expression, participates in lignin biosynthesis through the regulation of MdHST , MdCOMT1 , and MdCCoAOMT5 , contributes to anthocyanin accumulation by regulating MdGT5 and MdANS , facilitates pectin degradation via modulation of MdPME , delays carbohydrate metabolism in fruit through the regulation of MdRPI2 , MdPFK , MdPGAM , and MdPEPCK , and is implicated in auxin and biotin metabolism by controlling the expression of MdAMI1 and MdDTBS / Md7,8-DAPAAT . These findings provide critical reference value for further exploration and characterization of MdERF2 in apple fruit quality formation and maintenance.