抗生素和铜联合作用对蚕豆根尖细胞微核率的影响

为确定抗生素与重金属单一及联合作用对细胞遗传物质的损伤程度,以青皮蚕豆根尖细胞为试验材料,研究四环素类抗生素OTC(土霉素)、CTC(金霉素)、TTC(四环素)和重金属Cu单一以及联合作用对蚕豆根尖细胞微核率和微核指数的影响. 结果表明:①抗生素与Cu单独作用,二者c在0~1.6 mmol/L之间时,蚕豆根尖细胞微核率均高于3.33‰,微核指数均大于1.5,与CK(对照处理)相比差异显著(P<0.01)；随着c(抗生素)的增大,蚕豆根尖细胞微核率呈先减后增的趋势. ②抗生素与Cu联合作用时,蚕豆根尖细胞微核率和微核指数均小于单独作用时二者之和,交互作用表现为拮抗作用,其中c(抗生素)∶c(Cu)为1∶4时拮抗作用最明显,c(抗生素)∶c(Cu)为1∶1和1∶2时根尖细胞微核率呈减少的趋势,c(抗生素)∶c(Cu)为1∶8和1∶16时根尖细胞微核率呈增加的趋势. 研究显示,四环素类抗生素与Cu单一及联合作用于蚕豆根尖细胞时,均会对植物根尖细胞造成遗传损伤,但是联合作用时,抗生素在溶液中与Cu发生络合反应,从而可以在一定程度上降低对根尖细胞的遗传损伤. 

Influence of Antibiotics and Copper on Micronucleus Rate of Root-Tip Cells of Vicia-faba

In order to evaluate the degree of biological genetic injury induced by antibiotics and heavy metals, the genotoxic effects of oxytetracycline (OTC), chlortetracycline (CTC), tetracycline (TTC) and copper (Cu), as well as their individual and mixed pollutions in various proportions, and the degree of biological genetic injury were studied by micronucleus rate in root-tip cells of Vicia-faba. The results showed that:1) When the concentrations of the tetracycline antibiotics and Cu were 0-1.6 mmol/L, the micronucleus rates of Vicia-faba treated increased at different levels and were significantly different from the control group. All micronucleus rates were above 3.33‰, and all the micronucleus indexes were higher than 1.5. The results also showed that the experimental samples had mutagenicity. With the increase of the concentrations of tetracycline antibiotics, the micronucleus rate in root-tip cells of Vicia-faba showed an increasing trend after the first reduction. 2) Compared with the single effect of tetracycline antibiotics and Cu, there was antagonism when they were mixed in some proportion, and the trend was similar with the individual effect. The most obvious concentration for the antagonism was 1∶4. When the proportions were 1∶1 and 1∶2, the micronucleus rate declined, but it was adverse when the proportions were 1∶8 and 1∶16. These results demonstrated that the tetracycline antibiotics and Cu can cause biological genetic injury to root-tip cells of Vicia-faba, but when they were mixed, the injury reduced because of the complex interaction of Cu and tetracycline antibiotics.