泥鳅生长及抗氧化-解毒酶系统对水体中转Cry1Ab/Ac基因水稻残遗物的响应

Responses of growth and activities of antioxidant and detoxification enzymes of Misgurnus anguillicaudatus to transgenic Cry1Ab/Ac rice residues in water

在泥鳅养殖水体中添加稻秆粉模拟水稻残遗物生境,研究了泥鳅生长和肝胰脏抗氧化酶(SOD、CAT)与解毒酶(GST)活性对转Cry1Ab/Ac基因水稻‘华恢1号’(HH1)的响应。设计以HH1稻秆粉10 mg·L?1、50 mg·L?1、100 mg·L?1和200 mg·L?1 4个梯度浓度处理泥鳅为试验组,以非转Bt基因水稻‘明恢63’(MH63)稻秆粉处理组为阴性对照,不加稻秆粉的基础饲养组为空白对照。结果显示:在4种稻秆粉浓度下,HH1组与MH63对照组泥鳅的特定生长率、肥满度、内脏系数及SOD、CAT和GST酶活性均无显著差异(P>0.05);与空白对照比较,稻秆粉浓度升高对泥鳅生长的抑制逐渐增强,当浓度达到200 mg·L?1时,HH1组和MH63对照组泥鳅的特定生长率、内脏系数与CAT活性降低。研究结果表明,水体中低含量的转融合基因Cry1Ab/Ac水稻HH1稻秆粉对泥鳅的生长与生理酶活性没有明显影响,高浓度HH1和MH63稻秆粉均使泥鳅的生长和生理酶活性显著降低,这可能与养殖水体中浓度较高的悬浮稻秆粉妨碍了泥鳅的呼吸和滤食,及稻秆粉的分解降低了水体p H和溶氧量有关。

A loach （Misgurnus anguillicaudatus） aquaculture experiment was conducted in phytotron with aquatic water added with straw power in different concentrations （10 mg·L^-1, 50 mg·L^-1, 100 mg·L^-1, 200 mg·L^-1） of different rice varieties, which were transgenic CrylAb/Ac rice variety of ＇Huahui 1＇ （HH1） and non-Bt control rice variety of ＇Minghui 63＇ （MH63）. In the experiment, the loach basal fed without rice straw powder was set as the blank control. The specific growth rate, condition factor, and viscera somatic index as well as activities of antioxidant enzymes of superoxide dismutase （SOD） and catalase （CAT）, and detoxification enzyme of glutathione-s-transferase （GST） of loach were investigated after culture for 100 days. The aim of the study was to explore effects of transgenic Bt rice on aquatic animal through simulating rice residues in paddy water. The results showed no significant differences （P 〉 0.05） in specific growth rate, condition factor, viscera somatic, and activities of SOD, CAT and GST between loaches cultured in aquatic water added with HH1 and MH63 straw powders with four concentrations. Compared with the blankcontrol, the growth performance gradually decreased with increasing concentration of rice straw powder of both varieties. Furthermore, the specific growth rate, viscera somatic index and CAT activity of loach decreased obviously when loach was cultured in aquatic water with 200 mg·L^-1 of HH1 and MH63 straw powder. These results indicated that aquatic water with lower concentration of transgenic CrylAb/Ac rice straw powder had no obvious effect on growth performance and activities of antioxidant and detoxification enzymes of loach. When the concentration of rice straw powder was up to 200 mg·L^-1, the growth performance and activities of physiologic enzymes of loach decreased significantly, regardless of rice variety. It was suggested that higher level of rice straw powder in water hindered breathing of loach. In addition, the decomposition of rice straw powder in water induced decreasing of pH and dissolved oxygen.