Effects of Cr~(6+) Stress on Physiological and Biochemical Parameters of Soybean Seedlings

In order to study toxic mechanism of Cr6+ to plant,soybean seedlings with four leaves were cultured in Hoagland's nutrient solution that containing different concentration of Cr6+.Physiological functions of soybean seedlings were investigated after eight days treatment.The results showed that Cr6+ with low concentration(5 mg·L-1)stimulated the growth of soybean seedlings.Height and total chlorophyll content of soybean seedlings increased by 4.97% and 18.2% respectively after 5 mg·L-1 Cr6+ treatment.Moreover,MDA content decreased 15.95% and the POD activity did not have significant difference compared with control.however,Cr6+ with high concentration(10～100 mg·L-1)inhibited the growth of soybean seedlings,plant height,total chlorophyll content and POD activity of soybean seedlings all decreased,however,proline content and permeability of cell membranes increased after high concentration Cr6+ treatments.