高/低积累型菜心抗氧化系统对CIP胁迫响应的差异

Under ciprofloxacin (CIP) stress, reponse differences in antioxidant system between two cultivar of Chinese flowering cabbages with higher and lower accumulating CIP were investigated using hydroponic culture with different CIP concentrations (0-5.0 mg/L) for 40 days. Results showed that CIP accumulation in higher accumulating CIP cultivar (SI-JIU) was 1.1 to 2.1 times of that with lower accumulating CIP cultivar (CU-TAI). CIP bioaccumulation coefficient (14.6 - 24.0) of SI-JIU root was higher than CU-TAI root (11.3 - 13.5), but transfer coefficient of the two cultivars was compareble. At the same time, significantly higher protein contents in root, stem and leaf (0.29-1.04 g/L), significantly higher superoxide dismutase (SOD) activities (21.80-28.28 U/mgprot) and peroxidase (POD) activities in stem and leaf (46.82-82.73 U/mgprot) was observed in cultivar SI-JIU compared with those of cultivar CU-TAI (P < 0.05). Moreover, Compareble SOD activities (45.24-65.98 U/mgprot) and POD activities (105.8-185.9 U/mgprot) in root of cultivars SI-JIU and CU-TAI were observed. These results indicated that overall higher protein contents and antioxidant enzyme activities observed in cultivar SI-JIU compared with CU-TAI, resulted in lower malondialdehyde (MDA) concentrations (0.29 - 3.61 nmol/mg prot) in SI-JIU. So cultivar SI-JIU had greater CIP tolerance than cultivar CU-TAI and thus higher CIP accumulation was observed in SI-JIU compared to CU-TAI.