Transcriptome Analysis Identifies Genes Associated with Chlorogenic Acid Biosynthesis during Apple Fruit Development

As a predominant phenolic compound in apple fruits, chlorogenic acid (CGA) benefits human health due to its various antioxidant properties. However, little has been known regarding the molecular mechanism underlying CGA accumulation fruits. In this study, we measured content and relative enzymes’ activities during fruit development two different flesh-colored cultivars ‘Huashuo’ ‘Red Love’. The both decreased sharply from 30 days after full bloom (DAFB) 60 DAFB. Notably, flesh was relatively higher than that peel. Further, of C3H HCT enzymes downstream biosynthesis showed similar changing trend as content. Based on transcriptome data at DAFB DAFB, 23 differentially expressed synthesis-related genes were screened. Gene expression analyses further MdHCT1/2/4/5/6 MdC3H1/2/3 positively correlated variation cultivars. These findings establish theoretical foundation for study provide guidance nutrient improvement breeding programs.