镉胁迫对莴苣幼苗生长及抗氧化酶系统的影响

Effects of Cd stress on seedling growth and activities in antioxidant enzymes of lettuce

以笋王一号(Lactuca sativa L.sativa var.Angustata Irish.cv Sunwang NO.1)为材料,通过营养液水培试验,研究了不同浓度的Cd胁迫对莴苣幼苗生长和抗氧化酶的影响。试验结果表明:10～100μmol·L-1Cd2+对幼苗株高、根长、叶面积和叶数的增加具有明显的抑制作用,且随着浓度的增加抑制程度加重,但低浓度的Cd2+(1μmol·L-1)却产生了一定的促进作用;幼苗根、叶中MDA含量和G-POD、叶中SOD活性随着Cd处理浓度的增加明显增加,但根中的SOD在100μmol·L-1Cd胁迫下明显低于对照,同时,1μmol·L-1Cd对根和叶片中的APX和CAT活性有一定的激活效应,以后随着Cd处理浓度的提高表现为抑制效应,且随着Cd浓度的增加抑制效应逐渐增强。

Effects of cadmium at different concentrations on seedling growth and activities in antioxidant enzymes of lettuce cultivar, Sunwang No. 1, were studied after solution culture. It was shown that plant height, root length, leaf area and the amount of leaf were inhibited seriously by Cd at 10-100 μmol.L^-1, but were promoted by Cd at 1 μmol.L^-1. The content of MDA and activities of SOD and G-POD in roots and leaves increased gradually during increasing of Cd concentration, However, activities of SOD in roots de- creased significantly when Cd was at 100 μmol.L^-1. 1 μmol.L^-1 Cd can stimulate activities of CAT and APX in roots and leaves, however, the activities turned to be restrained and the effects increased gradually.