Abstract:

The effects of the different Pb content（0，150，450，1 350 mg · kg-1）stress on the active
oxygen metabolism in ginger leaves were studied with a ginger（Zingiber officinale Roscoe）cultivar
‘Laiwu Ginger’by using the method of sewage irrigation. The results showed that with the increase of Pb
stress level and exposure duration， productivity rate and H2O2 content increased significantly and then
decreased under excessive Pb stress，while MDA content and electrolyte leakage rate increased
continuously. After 40 days of Pb stress which was during the seedling stage，with the increase of Pb stress
level，the activities of superoxide dismutase（SOD），peroxidase（POD），catalase（CAT），glutathione
reductase（GR），ascorbate acid（APX），monodehydroascorbate reductase（MDHAR）and dehydroascorbate
reductase（DHAR）were enhanced markedly，and the contents of reduced ascorbic acid（AsA），totalascorbic acid（AsA + DHA），reduced glutathione（GSH）and total glutathione（GSH + GSSG）were
increased remarkably，and the ratios of AsA/DHA，GSH/GSSG were also increased significantly.
Moreover，with ginger growth going on and the stress time increasing significantly，the antioxidant
enzymes activities and the antioxidant substance contents were higher mostly under 150 mg · kg-1 mild Pb
stress and inhibited under excessive Pb stress，which indicated that the AsA-GSH cycle suffered serious
damage.

Key words: ginger, Pb stress, reactive oxygen metabolism