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本文研究了铬(Cr)对香根草(Chrysopogon zizanioides)生长以及抗氧化防御酶活性的影响,探讨其对Cr的解毒机制.在50 mg/L Cr处理条件下,植物地上部分和地下部分的生长量分别降低了36.8％和45.0％;Cr在植物地下部分的积累量(9807 μg/g干重)大于地上部分的积累量(8730 μg/g干重).随着Cr添加量的增加,光合色素和丙二醛含量增加,在30 mg/L Cr处理条件下含量达到最高,之后,随着Cr处理浓度的增加略有下降;同时,抗氧化防御酶(超氧化物歧化酶、过氧化氢酶和过氧化物酶)的活性显著提高,在较高浓度Cr处理下略有下降.同工酶结果显示在高浓度Cr处理下,超氧化物歧化酶、过氧化氢酶和过氧化物酶的条带强度降低.目前研究结果表明,高浓度Cr导致活性氧过量产生,从而增加了对香根草的氧化损伤,而光合色素、丙二醛、抗氧化酶含量的增加表明香根草对Cr有潜在的耐性机制.结果 表明,香根草具有对Cr的解毒机制,并可以积累高浓度的Cr.本文为更深入地研究根草对Cr的解毒机制提供了依据.“,”This study investigated the chromium (Cr) detoxification mechanism-induced changes in growth and antioxidant defence enzyme activities in Chrysopogon zizanioides.Plant growth decreased by 36.8％ and 45.0％ in the shoots and roots,respectively,in the 50 mg/L Cr treatment.Cr accumulation was higher in root (9807 μg/g DW) than in shoots (8730 μg/g DW).Photosynthetic pigments and malondialdehyde content increased up to the 30 mg/L Cr treatment,whereas they declined at higher doses.The activity of superoxide dismutase (SOD),catalase (CAT) and peroxidase (POX) were increased significantly with increasing of Cr dose but slightly declined at higher doses.Isozyme banding patterns revealed the expression of multiple bands for SOD,CAT and POX enzymes,and the band intensity decreased at high doses of Cr exposure.These results indicate that higher Cr doses increased the oxidative stress by over production of reactive oxygen species (ROS) in vetiver that had potential tolerance mechanism to Cr as evidenced by enhanced level of antioxidative enzymes,photosynthetic pigments,MDA contents.Therefore,vetiver has evolved a mechanism for detoxification and accumulates higher concentration of toxic Cr.This study provides a better understanding of how vetiver detoxifies Cr.