Changes in functional nutrients in red-fleshed kiwifruits after forchlorfenuron application leveraging a multi-omics...

Forchlorfenuron (CPPU), a plant growth regulator used to enhance kiwifruit yield, lacks multi-omics research in red-fleshed kiwifruits. This study analyzed CPPU's regulatory mechanisms on metabolites, nutrients, and gene expression in 'Zhonghua 50' during development and maturation. The results indicated that CPPU enhanced fruit size and weight, but this promotion decreased as kiwifruit approached maturity. CPPU promoted mitosis and affected the photosynthetic system and defense responses. CPPU affected multiple metabolic pathways and some key genes encoding enzymes in each pathway. Flavonoids other than anthocyanins down-regulated during fruit development, the changes of HCT-related gene expression possibly be related to fruit expansion. Sugar and organic acid changed insignificantly during the edible period, but the regulation of CPPU on kiwifruit flavor displayed cultivar specificity. The up-regulation of PAL would impact the resistance to biotic stresses. Some amino acids were down-regulated at the edible stage, which may negatively impact the fruit's nutritional value.