镉胁迫对转PprI基因油菜生理生化的影响

利用露天盆栽试验研究了不同浓度Cd胁迫下转PprI基因油菜和非转基因野生型油菜对Cd的吸收特性以及生理响应。结果表明：随着Cd胁迫浓度的升高，转基因和非转基因野生型油菜对Cd的吸收均显著增加，且二者地下部分的吸收都大于地上部分；在0.5 mg/kg Cd处理下，转基因和非转基因油菜对Cd的吸收差异不显著，但1和2 mg/kg处理下转基因油菜对Cd的吸收显著低于非转基因野生型油菜。两种油菜对Cd的富集系数和转运系数均随处理浓度的升高而降低；随着Cd浓度的增加，超氧化物歧化酶（SOD）活性呈现先上升后下降的趋势，且在相同处理浓度下，转基因油菜的SOD活性均高于非转基因野生型油菜；丙二醛（MDA）含量呈上升趋势，且其在转基因油菜中的含量均低于非转基因野生型油菜；叶绿素a和叶绿素b的含量随Cd浓度的升高而下降。因此PprI基因的导入，显著降低了油菜对Cd的吸收，提高了其可食部分安全性。

Effects of Cd stress on the physiological responses of oilseed rape transformed by PprI

The absorption characteristics and physiological responses of oilseed rape transformed by PprI were analyzed by the outdoor pot experiment under the stress of different concentrations of cadmium. Results indicated that the accumulation of Cd in both transgenic and wild type plants all increased significantly as the increase of Cd concentration in soil, and the content in roots was higher than upon-ground part. Under the 0.5 mg/kg Cd in soil, there were no significant differences between the accumulations of Cd in the two genotype oilseed rapes, but the accumulation of Cd in the transgenic plants was significantly lower than that in wild type at 1 and 2 mg/kg Cd treatments. The accumulation coefficient and translocation coefficient of plant reduced gradually with the increasing concentration of Cd. Under the stress of cadmium, superoxide dismutase (SOD) activity in all plants showed a trend of first increasing and then decreasing and SOD activity in all transgenic plants were higher than that in wild type. The content of malondialdehyde was increased, and the content of transgenic rapeseed was lower than that of non transgenic wild rape. The content of chlorophyll a and chlorophyll b in all plants decreased with the increase of Cd concentration. Therefore, the introduction of PprI gene significantly reduced the absorption of Cd in rapeseed, and increased the safety of the edible part.