Antioxidant metabolism of Chenopodium quinoa Willd. under salt stress

Abstract

The aim of this study was to understand the functioning and importance of antioxidant metabolism in the preservation of Chenopodium quinoa early seedling tissue against the oxidative damage caused by different concentrations of NaCl (0, 50, 100, 150 and 200 mM). The experimental design was completely randomized, with 5 treatments and 5 replications per treatment. After 7 days of treatments, the shoots and roots were evaluated for biomass allocation, betacyanin and antioxidant metabolism. The activity of superoxide dismutase showed similar behavior in both roots and shoots, and the greater activity of this enzyme was observed in higher concentrations of NaCl. The high SOD activity resulted in an increased production of H2O2 only in the shoots. H2O2 was probably removed by catalase, which exhibited behavior similar to that of superoxide dismutase. Higher levels of lipid peroxidation as well as lower levels of betacyanin were observed in the shoots at a concentration of 200 mM NaCl. All this metabolic adjustment was made without any impact on seedling dry matter accumulation. In this way, Chenopodium quinoa early seedlings are potentially tolerant to salinity, as an adjustment of their antioxidant metabolism was performed without affecting growth.