Effects of Mulching with Hyperaccumulator Straw on Antioxidant Enzyme Activity of Grape Seedlings under Cadmium Stress

Abstract

A pot experiment was conducted to study the effects of mulching with straw of different cadmium hyperaccumulators (Crassocephalum crepidioides, Galinsoga parviflora, Youngia japonica and Gnaphalium affine) on antioxidant enzyme systems of grape seedlings under cadmium stress. The results showed that all the straw-mulch treatments increased the peroxidase (POD) activity, superoxide dismutase (SOD) activity and soluble protein content of grape seedlings, but decreased the catalase (CAT) activity and malonic dialdehyde (MDA) content of grape seedlings. Mulching with straw of Y. japonica, the POD activity and SOD activity reached the highest level, which was 35.81% and 19.63% higher than monoculture respectively. Mulching with straw of Galinsoga parviflora, the soluble protein content reached the highest level, which was 29.23% higher than monoculture. However, all the straw-mulch treatments decreased CAT activity and MDA content compared with monoculture, and mulching with Y. japonica straw was the lowest, which was 85.49% and 68.49% lower than monoculture. In conclusion, covering different cadmium hyperaccumulator straws under cadmium stress can promote the growth of grape seedlings.