Effect of 5- Aminolevulinic acid and Genistein on the polyphenols, enzyme activity and gene expression in apple skin

Objective: To explore the changes of total polyphenol, anthocyanin, enzymes activity and gene expression in apple skin when the apples were spraied by 5- Aminolevulinic acid ( ALA) and Genistein ( GNT) . Methods: During the field experiments, 300mg·L- 1ALA, 21.62μg·L- 1GNT, and ALA + GNT were used to spray the‘Qinyang'apple when debagged, and determined the total polyphenol, anthocyanin, enzymes activity and gene expression in apple skin.Results: The red of apple skin deepen as the increase of anthocyanin content and relative gene expression quantity.The total polyphenol content reached the highest and polyphenol oxidase ( PPO) activity was lowest in which apple skin was spraied by ALA. The phenylalanin ammonia- lyase ( PAL) activity was not significant in the apples treated with GNT and ALA, but higher than the other three kinds of apples.Conclusion: ALA and GNT were conductive to the anthocyanin accumulation, so they can be used for promoting the coloration of early apples to improve market competitiveness.