Evaluation of Aluminum toxicity and phosphorus treatment on the physiological and biochemical traits of spinach (Spinacia oleracea L)

•The growth of Spinacia oleracea L. was decreased.•The activity of GPX, GR, and APX increased but the activity of CAT decreased.•The amount of photosynthetic pigments of S. oleracea was decreased.•P application reduced the activity of GP, GR, and APX enzymes.•Malondialdehyde and hydrogen peroxide amounts were changed by P application. In the acidic soils, Al toxicity is a major factor limiting plant growth and metabolism. It seems that the use of P can alleviate the toxic effects of Al. In this study, we investigated the single and combined effects of P treatment and Al-toxicity on the physiological and biochemical behavior of Spinacia oleracea L. Under Al stress, dry matter amount of shoots and roots decreased. Under Al stress, root Al contents were lower with P application than those without P application, while this effect for the leaf Al contents was completely reverse. Further, under Al stress, the activity of some enzymes, including GPX, GR and APX increased; but the activity of CAT and SOD showed a decrease and no change, respectively. P application reduced the activity of GPX, GR and APX enzymes. However, P treatment had not affected SOD activity. The amount of MDA, H2O2 and photosynthetic pigments of plant was affected by Al stress, but no change in protein content were observed. P application was able to change the effect of Al stress on MDA and H2O2 amounts. In this study, under Al stress, with P application antioxidant enzymes activity to some extent improved and the peroxidation of lipids decreased.