峨眉山珍稀植物鹅掌楸组培过程中的膜脂过氧化

Lipid Peroxidation of Rare Plant Chinese Tulip Tree in Mount Emei During Tissue Culture

鹅掌楸(Liriodendron chinense(Hemsl.)Sarg.)是中国特有珍稀树种。鉴于目前还鲜有野生鹅掌楸组培过程生理生化变化的相关报道。本研究以峨嵋山野生鹅掌楸茎尖芽为外植体进行组织培养,并对其继代培养再生过程中超氧阴离子自由基(O2-)、过氧化氢(H2O2)和丙二醛(MDA)含量的变化进行了测定。研究结果表明,随着培养时间的延长,植物体中O2-和MDA含量呈现逐渐增加的变化趋势。这表明在连续继代培养条件下,植物体内活性氧会积累,引起膜脂过氧化。H2O2含量呈"S"形曲线变化,并随着再生芽的分化而上升,因此,H2O2不仅参与了膜脂过氧化过程,还可能作为一种细胞信号物质参与诱导细胞分化和再生芽的形成。该研究也为进一步用组织培养法保存峨眉山珍稀植物鹅掌楸种质资源提供了参考。

Chinese tulip tree （Liriodendron chinense （Hemsl.） Sarg） is an endemic rare tree species in China. Whereas the physiological and biochemical changes of it during the tissue culture was quite few reported yet. In this research, we employed shoot-tips of wild Chinese tulip tree in Mount Emei as explants for tissue culture, and mes ured the content changes of super oxygen-anion flee radicals （O2）, hydrogen peroxide （H2O2） and malondialdehyde （MDA） during the secondary culture. The results demonstrated that the content of O2- and MDA increased gradually along with the continuation of the culture time, which illustrated that the active oxygen accumulated in continuous secondary culture, causing membrane lipid peroxidation. Furthermore, the content of H2O2 changed in S-shaped curve, and increased with the differentiation of the regenerated bud. As a result, we inferred that H2O2 might be not only involved in lipid peroxidation, but also in cell differentiation induction and regenerated bud formation as a signal molecule. This research would also facilitate the germplasm conservation of rare plant Chinese tulip tree in Mount Emei by employing tissue culture approach.