We aimed to evaluate if plants with different nutrient availability evidenced a different capacity to
overcome drought-induced oxidative stress. Membrane peroxidative damages as MDA concentration and
the activity of several antioxidant enzymes were determined in leaves of well watered (WW) and water
stressed (WS) H. annuus plants grown either with adequate (Adeq Nutr) or limited (Limit Nutr) nutrient
regimes. Constitutive capacity to eliminate ROS was not overall changed by growing plants with different
nutrient supply regimes, but a diverse enzyme-dependent response was observed. In response to drought
SOD and DHAR activity increased only in plants with limited nutrient supply, while in plants with
adequate nutrient supply the activity of these enzymes did not change and were constitutively higher, but
the activity APX increased by 50%. The subtle observed changes in the activity of the antioxidant
enzymes are discussed, given that no oxidative damage was observed