Yin Liyan, Huang Jiaquan, Huang Wenming, Li Dunhai, Wang Gaohong, Liu Yongding
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China.
Toxicon. 2005 Oct;46(5):507-12. doi: 10.1016/j.toxicon.2005.06.015.
Microcystins are cyclic heptapeptide hepatoxins produced by cyanobacteria. It has been shown that microcystins have adverse effects on animals and on plants as well. Previous researches also indicated that microcystins were capable of inducing oxidative damage in animals both in vivo and in vitro. In this study, tobacco BY-2 suspension cell line was applied to examine the effects of microcystin-RR on plant cells. Cell viability and five biochemical parameters including reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione peroxide (GPX) and peroxide dismutase (POD) were investigated when cells were exposed to 50mg/L microcystin-RR. Results showed that microcystin-RR evoked decline of the cell viability to approximately 80% after treating for 144 h. ROS levels, POD and GPX activities of the treated cells were gradually increased with a time dependent manner. Changes of SOD and CAT activities were also detected in BY-2 cells. After 168 h recovery, ROS contents, POD, GPX and CAT activities returned to normal levels. These results suggest that the microcystin-RR can cause the increase of ROS contents in plant cells and these changes led to oxidant stress, at the same time, the plant cells would improve their antioxidant abilities to combat mirocystin-RR induced oxidative injury.
微囊藻毒素是蓝藻产生的环状七肽肝毒素。已表明微囊藻毒素对动物以及植物均有不良影响。先前的研究还表明，微囊藻毒素在体内和体外均能诱导动物产生氧化损伤。在本研究中，应用烟草BY-2悬浮细胞系来检测微囊藻毒素-RR对植物细胞的影响。当细胞暴露于50mg/L的微囊藻毒素-RR时，研究了细胞活力以及包括活性氧（ROS）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPX）和过氧化物歧化酶（POD）在内的五个生化参数。结果显示，处理144小时后，微囊藻毒素-RR使细胞活力下降至约80%。处理后的细胞中ROS水平、POD和GPX活性随时间呈逐渐增加的趋势。在BY-2细胞中也检测到了SOD和CAT活性的变化。恢复168小时后，ROS含量、POD、GPX和CAT活性恢复到正常水平。这些结果表明，微囊藻毒素-RR可导致植物细胞中ROS含量增加，这些变化导致氧化应激，同时，植物细胞会提高其抗氧化能力以对抗微囊藻毒素-RR诱导的氧化损伤。
