商陆耐重金属Cd关键酶抗氧化酶的研究

研究商陆(Phytolacca americana L.)对Cd胁迫的抗氧化酶响应,对于揭示其耐Cd机制具有重要意义.商陆幼苗在200μmol/L或400 μmol/L CdCl2营养液中处理4 d,叶片活性氧自由基和MDA含量升高,膜透性增加,光合速率降低,表明Cd胁迫诱导产生氧化胁迫.随着Cd处理含量的提高和时间的...

Antioxidative Enzymes Play Key Roles in Cadmium Tolerance of Phytolacca americana

Phytolacca americana L. has the capacity to take up and accumulate to very high levels heavy metals such as Mn and Cd, and is used for phytoextraction of heavy metal contaminated soils. The role of antioxidative enzyme of Phytolacca americana in response to Cd stress is unknown. The 6-week-old seedlings of Phytolacca americana were exposed to half strength Hoagland solution with 200 micromol/L CdCl2 or 400 micromol/L CdCl2 for 4 days. The content of H2O2 and MDA, and electrolyte leakage increased, while the photosynthetic rate decreased, indicated that the oxidative damage induced by Cd stress in Phytolacca americana was one of the metal toxicity mechanism. The activities of SOD and POD increased rapidly with elevated Cd concentration and exposure time, CAT activity was stable in response to 200 micromol/L CdCl2 stress, and increased only at 3 d later upon 400 micromol/L CdCl2, treatment. Suggested that the enzymatic antioxidation capacity played important role in Cd tolerance of hyperaccumulator plant.