Variation in polyphenolic composition, antioxidants and physiological characteristics of globe artichoke (Cynara cardunculus var. scolymus Hayek L.) as affected by drought stress

Different levels of irrigation regimes (20%, 50% and 80% depletion) were applied to evaluate polyphenolic compounds and physiological traits in leaves and heads of artichoke. According to HPLC analysis, chlorogenic acid was the most abundant phenolic acid in leaves (481 mg/Kg DW) and the second most abundant compound (after caffeic acid) in heads (213 mg/Kg DW) in non-stress condition. During water shortage, chlorogenic acid, caffeic acid, 1,3-dicaffeoylquinic acid and 1,5-dicaffeoylquinic acid increased, while apigenin, and luteolin decreased in both parts. The elevation in the contents of proline, H2O2, malondialdehyde and the activities of antioxidant enzymes were also observed under stress conditions. Catalase was the most active antioxidant enzyme in all treatments. Water stress led to increase in carotenoids and decrease in chlorophyll content of the heads. Finally, the irrigation regimes can be selected by considering the yield components as well as favorite compounds for food and pharmaceutical purposes.