Response of enzymatic and non-enzymatic antioxidant defense systems of Polygonum hydropiper to Mn stress

The response of enzyme and non-enzymatic antioxidants of Mn hyperaccumuator, Polygonum hydropiper(P. hydropiper), to Mn stress was studied using hydroponics culture experiments to explore the mechanism of Mn tolerance in this species. Results showed that both chlorophyll and carotenoid contents significantly(p<0.05) decreased with increasing Mn treatment levels(0, 0.5, 1, 2, 4, and 8 mg/L) in hydroponics. The concentrations of malondialdehyde(MDA) and hydrogen peroxide(H_2O_2) in the root and shoot of P. hydropiper were accumulated under Mn stress. Meanwhile, the anti-oxidative functions of several important enzymes, including superoxide dismutase(SOD), catalase(CAT), ascorbate peroxidase(APX) and peroxidase(POD) in plants were stimulated by Mn spike in leaves and roots, especially at low Mn stress; while sulfhydryl group(—SH) and glutathion(GSH) were likely involved in Mn detoxification of P. hydropiper under high Mn stress.

The response of enzyme and non-enzymatic antioxidants of Mn hyperaccumuator, Polygonum hydropiper （P. hydropiper）, to Mn stress was studied using hydroponics culture experiments to explore the mechanism of Mn tolerance in this species. Results showed that both chlorophyll and carotenoid contents significantly （p〈0.05） decreased with increasing Mn treatment levels （0, 0.5, 1, 2, 4, and 8 mg/L） in hydroponics. The concentrations of malondialdehyde （MDA） and hydrogen peroxide （H202） in the root and shoot of P hydropiper were accumulated under Mn stress. Meanwhile, the anti-oxidative functions of several important enzymes, including superoxide dismutase （SOD）, catalase （CAT）, ascorbate peroxidase （APX） and peroxidase （POD） in plants were stimulated by Mn spike in leaves and roots, especially at low Mn stress; while sulfhydryl group （--SH） and glutathion （GSH） were likely involved in Mn detoxification ofP. hydropiper under high Mn stress.