Changes of health-promoting bioactive compounds and related enzymes of 'Hutai No.8' grape (Vitis vinifera L.) in response to deficit irrigation.

The objective of this study was to investigate the changes of health-promoting bioactive compounds and related enzymes of 'Hutai No.8' grape (Vitis vinifera L.) in response to deficit irrigation. The experiment had five irrigation treatments: FI (75%–90% of FC [field water holding capacity] from budburst to full maturation), DI (same as FI except 50%–60% of FC from peasize to full maturation), DI1 (same as FI except 50%–60% of FC from peasize to véraison), DI2 (same as FI except 50%–60% of FC from véraison to mid-ripening) and DI3 (same as FI except 50%–60% of FC from mid-ripening to full maturation). Results showed that contents of different bioactive compounds and activity of related enzymes in grape leaves and berries tissue increased over control due to the application of deficit irrigation, and these changes were dependent on the fruit developmental period. Correlation analysis revealed the most significant positive relationship was observed between bioactive compounds and related enzymes activities in the grape seeds (r = 0.804). However, the most significant negative relationship was observed between bioactive compounds and polyphenol oxidase activity in the grape leaves (r = −0.769). Deficit irrigation treatment after véraison is an efficient approach for inducing the accumulation of bioactive compounds. [ABSTRACT FROM AUTHOR]