中文摘要：

以两种油菜品种天油2号和陇油6号作为供试材料，研究了MAPKK抑制剂U0126对低温胁迫油菜幼苗叶绿素、凡／‰、抗氧化酶活性的影响．结果表明：低温胁迫下，油菜幼苗叶绿素质量分数、Fv／Fm下降，MDA质量分数增加，CAT，APX，GR，SOD活性先增加后下降．MAPKK抑制剂U0126预处理再低温胁迫后，与单独低温处理相比，叶绿素质量分数、Fv／Fm降低，MDA质量分数增加，抗氧化酶活性均下降．表明MAP激酶级联途径参与油菜抗低温胁迫转导途径，缓解低温胁迫造成的氧化损伤，对其抗氧化损伤起了一定正调控作用．

英文摘要：

An experiment on Brassica napu seedings （Tianyou 2 and Longyou 6） was conducted to investigate the effects of MAPKK inhibitors on the chlorophyll content, maximum rate of photochemistry（Fv/Fm）, and various antioxidant enzyme activities of Brassica napus seedings under low temperature stress. The results show that, in Brassica napu seedings under low temperature stress the chlorophyll content and the maximum rate of photochemistry were reduced, the content of MDA increased, while the activities of CAT, APX, GR, SOD increased first but decreased afterwards. Compared with low temperature treatment alone, MAPKK inhibitors U0126 pretreatment decreased the chlorophyll content and the maximum rate of photochemistry, as well as various antioxidant enzyme activities, while MDA content increased. In conclusion, MAPK cascades take part in the transduction pathways of low temperature stress and play a positive role in antioxidative damage.