镉胁迫对续断菊与玉米间作体系中植物叶片抗氧化酶活性的影响

为探讨续断菊/玉米间作种植模式对Cd污染的响应机制,通过盆栽实验,研究了不同质量分数的Cd(0,50,100,200 mg/kg)对玉米与续断菊间作体系下植物叶片可溶性蛋白、丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和总抗氧化酶(T-AOC)活性的影响.结果表明:在0和50 mg/kg Cd胁迫条件下,间作玉米和续断菊叶片可溶性蛋白含量降低了8.1%~34.1%,当Cd处理质量分数为100和200 mg/kg时,间作玉米叶片和续断菊叶片可溶性蛋白显著比单作增加了34%~69.1%;间作玉米叶片MDA含量较单作增加了6.1%~ 64.6%,续断菊叶片MDA含量较单作降低了9.7%~ 58.7%;在不同Cd 质量分数处理下,无论是单作还是间作,玉米和续断菊叶片中SOD、POD、CAT和T-AOC活性均随Cd质量分数的增加而增加,仅Cd 质量分数达到200 mg/kg时CAT活性有所下降;同一Cd 质量分数处理下,间作玉米叶片SOD、POD(200 mg/kg除外)、CAT和T-AOC活性均较单作降低,分别较低了15.1%~48.3%、2.8%~ 24.7%、5.2%~42.3% 和20.7%~31.9%;间作续断菊叶片T-AOC较单作增加了11.2%~26.4%.总体上,在一定质量分数的Cd胁迫下,玉米和续断菊叶中的MDA含量及抗氧化酶活性均有所提高以维持正常生长,表明抗氧化酶在清除Cd毒害产生的活性氧自由基和提高Cd 耐性中有重要作用.

Effects of Cd Stress on Antioxidant Enzymes Activity of Sonchus asper L. Hill. and Zea mays L. in Intercropping System

Intercropping has shown the potential to phytoremediate heavy metal polluted soils. A pot experiments were carried out to explore the antioxidant responses of Sonchus asper L. Hill and Zea mays L. to Cd pollution under intercropping system. Four cadmium levels (0, 50, 100, 200 mg/kg) was designed to study the effects of Cd on the contents of soluble protein and MDA, activities of SOD, POD, CAT and T-AOC in leaves of S. asper and Z.mays. The result showed that: with 0 and 50 mg/kg soil Cd content, the content of soluble protein in S. asper and Z.mays decreased by 8.1%~34.1% under intercropping, and with 100 and 200 mg/kg soil Cd content, the content of soluble protein in S. asper and Z.mays significantly increased by 34%~69.1%. Compared with monoculture, MDA contents of Z.mays increased by 6.1%~ 64.6% and decreased by 9.7%~58.7% in S. asper under intercropping. Under both monoculture and intercropping systems, the SOD, POD, CAT, T-AOC activities of S. asper and Z.mays all increased with increasing Cd concentrations. But Cd addition at 200 mg/kg caused CAT activity decrease. Under the same Cd concentration treatment, SOD activity, POD activity (except 200 mg/kg) , CAT activity and T-AOC activity of Z.mays decreased by 15.1%~48.3%, 2.8%~ 24.7%, 5.2%~42.3% and 20.7%~31.9% in intercropping, compared with monoculture. Under intercropping, T-AOC activity of S. asper increased by 11.2%~26.4%. In general, intercropping could improve antioxidant enzymatic system in Z.mays and S. asper , thus alleviate Cd toxicity under Cd stresses. The enzymatic antioxidation capacity plays important role in Cd tolerance of plant.