镉、铅胁迫对麻疯树幼苗生长的影响

Effects of Cd^(2+) and Pb^(2+) on the seedling growth of Jatropha curcas L.

采用盆栽试验研究了不同浓度的镉(Cd2+)和铅(Pb2+)对麻疯树幼苗生长及幼苗叶片的叶绿素含量、叶片细胞超微结构、丙二醛(MDA)含量、可溶性蛋白含量以及过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性的影响。结果表明,两种重金属处理后,麻疯树幼苗的株高、根长、根重和地上鲜重抑制作用较为明显;随着Cd2+、Pb2+浓度的增大,叶片叶绿素总量总体呈下降趋势,MDA和可溶性蛋白含量升高,SOD活性则先上升后下降。Pb2+胁迫下,POD活性随浓度呈先升后降的趋势,CAT活性则逐渐上升,叶绿体双层膜分辨不清,基质大量溢出;Cd2+胁迫下,POD活性随浓度缓慢上升,CAT活性则是先上升后下降,叶绿体结构轻微变形,呈圆形且有肿胀现象,基质少量溢出。

The effects of individual Cd^2＋ and Pb^2＋ pollution on seedling growth, chlorophy Ⅱ content, MDA content, soluble protein content and 3 antioxidant enzymatic activities （SOD, POD, CAT） in the antioxidant system of Jatropha curcas L. were tested with coneent ration gradients of Cd^2＋ and Pb^2＋ added to soil respectively. The concentrations of Cd^2＋ and Pb^2＋ were 0, 50, 100 and 0, 500, 1 000 mg/L, respectively. With the treatment of Cd^2＋ and Pb^2＋, plant height, root length, root weight and shoot weight of the J. curcas L. produced significant inhibition. With the same content of Cd^2＋ and Pb^2＋, the radicle length was more strongly inhibited than stems elongation. The ehlorophy Ⅱ content decreased as content rations of Cd^2＋ and Pb^2＋ increased, but the MDA content and soluble protein content increased. The proline content and SOD activity tended to increase at lower concentrations （50 mg/L Cd^2＋, 500 mg/L Pb^2＋） and decrease at higher concentrations （100 mg/L Cd^2＋, 1 000 mg/L Pb^2＋）. POD activity tended to increase at lower concentrations （500 mg/L Pb^2＋.） and decrease at higher concentrations （1 000 mg/L Pb^2＋）, and it tended to increase as concent rations of Cd^2＋. The activity of CAT tended to increase at lower concentrations （50 mg/L Cd^2＋） and decrease at higher concentrations （100 mg/L Cd^2＋）.