Two oilseed rape genotypes (Jiu-Er-13XI and Zheyou-50), differing in seed oil content, were subjected to cadmium (Cd) stress in hydroponic experiment. Genotypic differences were observed in terms of tolerance to Cd exposure. Cd treatment negatively affected both genotypes, but the effects were more devastating in Jiu-Er-13XI (low seed oil content) than in Zheyou-50 (high seed oil content). Jiu-Er-13XI accumulated more reactive oxygen species (ROS), which destroyed chloroplast structure and decreased photosynthetic pigments, than Zheyou-50. Total fatty acids, especially 18:2 and 18:3, severely decreased as suggested by increase in MDA content. Roots and shoots of Jiu-Er-13XI plants accumulated more Cd content, while less amount of tocopherol (Toc) was observed under Cd stress, than Zheyou-50. Conversely, Zheyou-50 was less affected by Cd stress than its counterpart. It accumulated comparatively less amount of Cd in roots and shoots, along with reduced accumulation of malondialdehyde (MDA) and ROS under Cd stress, than Jiu-Er-13XI. Further, the level of Toc, especially α-Tocopherol, was much higher in Zheyou-50 than in Jiu-Er-13XI, which was also supported by high expression of Toc biosynthesis genes in Zheyou-50 during early hours. Toc not only restricted the absorption of Cd by roots and its translocation to shoot but also scavenged the ROS generated during oxidative stresses. The low level of MDA shows that polyunsaturated fatty acids in chloroplast membranes remained intact. In the present study the tolerance of Zheyou-50 to Cd stress, over Jiu-Er-13XI, is attributed to the activities of Toc. This study shows that plants with high seed oil content are tolerant to Cd stress due to high production of Toc.

在水培试验中，对两种不同籽油含量的油菜油菜基因型（Jiu-Er-13XI和Zheyou-50）进行了镉（Cd）胁迫处理。在对镉暴露的耐受性方面观察到基因型差异。镉处理对两种基因型均产生负面影响，但在Jiu-Er-13XI（低籽油含量）中的影响要比在Zheyou-50（高籽油含量）中更具破坏性。与Zheyou-50相比，Jiu-Er-13XI积累了更多的活性氧（ROS），破坏了叶绿体结构并减少了光合色素。总脂肪酸，特别是18：2和18：3，由于MDA含量的增加而严重降低。与Zheyou-50相比，Jiu-Er-13XI植物的根和芽中Cd含量更高，而在Cd胁迫下观察到的生育酚含量却更低。反过来，Zheyou-50受镉胁迫的影响要小于其对应的胁迫。与Jiu-Er-13XI相比，它在根和芽中积累的Cd量相对较少，同时丙二醛（MDA）和ROS的积累量减少。此外，Zheyou-50中Toc的水平，特别是α-生育酚要比Jiu-Er-13XI高得多，这也得到了在早些时候Zheyou-50中Toc生物合成基因高表达的支持。Toc不仅限制了根对Cd的吸收及其向芽的易位，还清除了氧化胁迫期间产生的ROS。MDA含量低表明叶绿体膜中的多不饱和脂肪酸保持完整。在本研究中，浙九50对Cd胁迫的耐受性在Jiu-Er-13XI上归因于Toc的活性。