The present work was carried out in greenhouse conditions at the Centro de Investigación en Alimentación y Desarrollo AC in Delicias, Chihuahua, México. Four different concentrations (0, 25, 50 and 100 μM L-1) of Zn chelate and sulfate were used to study the antioxidant system of Phaseolus vulgaris L. Three genes related with antioxidant activity [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] were selected for expression study. Results showed that when Zn chelate at 50 and 100 μM L-1 were applied SOD was repressed and GSH-Px expression was low at 0, 25 and 100 μM L-1 while with sulfate form SOD expression was low and GSH-Px expression was strong in all treatment. CAT was highly expressed in all form and treatments. For a biochemical study the same enzymes were spectrophotometrically measured. SOD activity shows differences in both forms of Zn, chelate form was different at 25, 50 and 100 μM L-1 with less activity at 100 μM L-1 and sulfate treatment shows differences in all concentrations used. GSH-Px activity shows significant differences with sulfate form at 25, 50 μM L-1 where at 50 μM the activity was higher and low at 100 μM L-1, CAT does not exhibit significant differences but with chelate treatment at 50-100 μM L-1 the activity was higher compared to sulfate. Finally, to raise the Zn concentration in bean under biofortification program is a promising strategy in cropping systems in order to increase the ingestion of zinc and antioxidant capacity in the general population and provided the benefits that this element offered in human health.
Keywords: Antioxidant; Biofortification; Chelate; Expression; Sulfate.