Effects of strontium stress on antioxidant characteristics of oilseed rape seedling

Seedlings of oilseed rape (Brassica napus L.) were treated with different concentration of Sr2+ (0, 10, 20, 40 mmol/L SrCl2) for 0, 7, 14, 21 days under quartz sand and Hoagland solution culture, and the antioxidant characteristics and Sr2+ accumulation of seedling were investigated. Rape seedlings showed high accumulation capacity for strontium, especial the leaves. But the accumulation capacity declined with the increasing of Sr2+ concentration. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) increased with the increasing of Sr2+ concentration and then declined with the extention of the stress time. The activity of catalase (CAT) and peroxidase (POD) declined with the increasing of the Sr2+ accumulation capacity. This study showed that oilseed rape had a very high strontium-tolerant and strontium-uptake capacity, and leaf was the organ that accumulates most of strontium. The accumulation capacity and activity of CAT, POD exhibited a significantly-negative correlation. (authors)