Water status, biochemical and hormonal changes involved in the response of Olea europaea L. to water deficit induced by partial root-zone drying irrigation (PRD)

Changes in the plant water status, biochemical and hormonal responses, were investigated three olive cultivars (Arbequina, Arbosana Chetoui) grown a super-high-density orchard under partial root-zone drying (PRD) irrigation. Four irrigation treatments applied during two growing seasons (2015 2016); control treatment (100 % ETc) irrigated at 100 of crop evapotranspiration on both parts PRD PRD, 75 50 PRD) %, only one alternated part root-zone. The results indicated that studied showed clear difference their response to Arbequina cultivar has shown conservative strategy for using since relative content (RWC) stem potential (?stem) reduced more Chetoui In fact, led strong activation secondary metabolites with antioxidant properties such as pigments, phenols flavonoids. Other metabolic changes, including accumulation soluble sugars proline have been also triggered by Among cultivars, displayed highest levels proline, total sugars, flavonoids, lowest ones Malondialdehyde (MDA) hydrogen peroxide (H2O2). increase Superoxide dismutase (SOD), catalase (CAT) guaiacol peroxidase (POD) activity reduction polyphenoloxidase (PPO) pronounced 2016 season activities obtained from Arbequina. For all increased phytohormones concentration both, roots leaves recorded 2016. leaves, abscisic acid (ABA), jasmonic (JA), salicylic (SA) indole-3-acetic (IAA). induces higher ABA, JA IAA dried than wetted ones. Taken together, physiological mechanisms induced effective suggesting better protection foliar functions compared other its adaptability PRD.