【作者】 曹玉伟；

【导师】 郭长虹；

【作者基本信息】 哈尔滨师范大学 ， 遗传学， 2009， 硕士

【摘要】 本研究采用不同浓度的硝基苯及维生素C与硝基苯联合处理烟草,检测硝基苯胁迫对烟草生理特性的影响,利用彗星实验技术检测不同浓度硝基苯对烟草叶片DNA的损伤情况,同时通过比较这两种不同处理方式下烟草DNA损伤情况及生理特性的变化,探讨硝基苯导致烟草DNA损伤的分子机制。主要研究结果如下:彗星实验结果表明,硝基苯胁迫浓度较低时,对烟草DNA影响较小,当升高到一定浓度后,烟草DNA损伤明显增加,表现出一定的剂量效应关系。添加维生素C后,烟草DNA损伤程度与单独使用硝基苯胁迫处理时相比明显降低。生理指标检测结果表明,烟草体内各种抗氧化酶CAT、POD、SOD总活性与其体内产生的氧化性自由因子H₂O₂、O₂^-等含量有相关关系。O₂^-含量在根尖中很高,且随硝基苯浓度先升高后降低,而在叶片中没有表现出与硝基苯叶片浓度的相关变化;H₂O₂则是随着硝基苯浓度升高而升高,且在100mg·L-1升高更加明显,在加入Vc后,二者含量都有降低趋势。MDA含量不论在根尖还是叶片,含量随硝基苯浓度升高而上升,当加入Vc后MDA含量有所降低,说明Vc具有降低硝基苯对DNA和生物膜损伤的作用。综合分析彗星实验和生理指标检测的结果,推测硝基苯导致烟草DNA损伤可能是通过各种活性氧自由基造成的。更多还原

【Abstract】 In this study, mainly explored tobaccos’physiological characteristics, and using comet assay to detect DNA damages of tobacco grown in different concentrations of nitrobenzene or a certain concentration of vitamin C with nitrobenzene. Comparing physiological characteristics or DNA damages of two different treatments, and explore DNA damages mechanism induced by nitrobenzene. The main results are the following:Comet assay results showed that low concentrations of nitrobenzene was less affected on tobacco’s DNA, as it rises to a certain concentration, a marked increase in tobacco DNA damages was gained, which shows a dose-response relationship, and DNA damages significant reduced of tobacco as added vitamin C.Physiological test results show that a variety antioxidant enzymes of tobacco vivo CAT, POD, SOD total activity changes with its contents of the free factors, H₂O₂, O₂^- and so on. O₂^- contents very high in roots, and rises with the nitrobenzene concentration, then reduces, and in leaves, O₂^- shows no relevant changes with nitrobenzene. H₂O₂ increased with the concentration of nitrobenzene, and increased more significantly grown in 100mg·L^-1 nitrobenzene. When added Vc, they have a lower trend. MDA content increased with nitrobenzene in both the apical or leaves, when added Vc, its congtent decreased, but marginally lower, and shows Vc has effects to reduce damages of DNA or biological membrane.Multifactorial Analysis the results of comet assay and physiological shows that nitrobenzene induce tobacco DNA damages may be caused by various oxidation factors.更多还原