Response of health-promoting bioactive compounds and related enzyme activities of table grape (Vitis vinifera L.) to deficit irrigation in greenhouse

Abstract

ABSTRACTGrape (Vitis vinifera L.) containsabundant secondary metabolites that are beneficial to humanhealth. Previous studies reported that deficit irrigation alters fruitcomposition, however, the mechanisms underlying the responseof health-promoting bioactive compounds to deficit irrigation indifferent phenological stages and those of associated metabolismrelatedenzymes remain unclear. Continual maintain irrigation (CI),deficit irrigation throughout growth seasons (DI), deficit irrigationbefore (ED) and after (LD) fruit set were performed for investigatingthe response of bioactive compounds and related enzyme activitiesin grape berries to deficit irrigation. Resveratrol, anthocyanins,phenylalanine ammonialyase (PAL) and superoxide dismutase(SOD) in grape berries were increase in DI, ED and LD treatments,whereas proanthocyanidins and polyphenol oxidase (PPO) weresignificantly increased in CI treatment. Significant differenceswere observed between the groups with respect to resveratrol,anthocyanins and PAL activity. Grapevine evapotranspirationwere decreased in ED and LD treatments, with water useefficiency increased. Principal component analysis showed a clearseparation among four treatments, and the LD had the highesttotal membership function value. Changes of bioactive compoundscontent can be attributed to PAL activity. Deficit irrigation after fruitset can promote the production of functional and superior qualitytable grape in greenhouse.