Effect of Exogenous Selenium on Activity of Glutathione Peroxidase and Uptake and Conversion of Selenium in Several Brassica Vegetables

Pot experiment carried out to investigate the effects of Se level (0, 0.5, 1.0, 2.5 and 5 mg kg(-1)) in soil on the growth, activity of glutathione peroxidase (GSH-px), and Se absorption and transformation of Brassica vegetables (included Brassica rapa var. perviridis, B. rapa ssp. chinensis, B. rapa var. purpuraria, B. pekinensis, B. oleracea var. capitata). The results showed that application of exogenous Se (0.5. 5.0 mg kg(-1)) in soil increased the growth of Brassica vegetables, and the total biomass (dry weight) was increased by 8.22-101.22% compared to control, but high concentration of selenium (2.5 or 5.0 mg kg(-1)) inhibited the growth of vegetables. Selenium increased GSHi-px activity of leaf and root in most vegetables. Exogenous Se significantly increased the total Se of plant and concentration of organic Se in the edible parts of vegetables, and Se concentrations of tissues in Brassica vegetables were positively correlated with the concentration of Se. Selenium concentrations in the edible parts of vegetables were 1.06-52.40 times compared to the control. The highest conversion of organic Se was found in B. rapa var. perviridis. by 94.81%. At the same Se level, the highest of Se uptake ability was observed in B. rapa var. purpuraria, and B. oleracea var. capitata was the lowest. Selenium enrichment coefficient (BCF) of B. rapa var. perviridis came was the highest at the same Se level, and B. oleracea var. capitata was the lowest. Selenium-rich B. rapa var. perviridis can be planted to supplement selenium content of human body in se-deficient areas. (c) 2018 Friends Science Publishers