核黄素诱导烟草悬浮细胞酚类物质和木质素的积累

 【目的】阐明核黄素对烟草悬浮细胞苯丙氨酸解氨酶(phenylalanine ammonia-lyase,PAL)、过氧化物酶(peroxidase,POD)活性以及抗病相关的酚类物质、木质素等次生代谢产物含量的影响。【方法】1 mmol?L-1的核黄素处理烟草悬浮细胞,用生物化学、细胞化学和高效液相色谱(high performance liquid chromatography,HPLC)等方法测定苯丙烷代谢有关的生理和生化指标。【结果】核黄素处理后,PAL和POD活性明显升高,处理12 h 和24 h后酶活性分别达到峰值;荧光观察细胞壁积累了更多的酚类物质,胞内和胞外scopoletin(7-羟基-6-甲氧基香豆素)含量明显升高,在处理12 h后都达到峰值,分别是对照的3.6和3.9倍;细胞染色和含量测定表明,核黄素处理后烟草悬浮细胞沉积了更多的木质素,处理24 h和48 h后,木质素含量分别为对照的1.5和1.8倍。【结论】核黄素处理后提高了烟草悬浮细胞PAL、POD活性,积累了更多与抗病有关的次生代谢产物。

Induction of Phenolic Compounds and Lignin in Cultured Tobacco Cells Treated with Riboflavin

【Objective】 To investigate the effects of riboflavin on phenylpropanoid metabolism in tobacco cells. The activity of phenylalanine ammonia-lyase (PAL) and peroxidase (POD), accumulation of phenolic compounds and lignin were determined. 【Method】 Tobacco suspension cells treated with 1 mmol?L-1 riboflavin were used to investigate the effect of the phenylpropanoid metabolism by biochemical, cytochemical and HPLC (high performance liquid chromatography) analysis. 【Result】 The activity of PAL and POD increased and reached the highest level at 12 h and 24 h after treatment with riboflavin, respectively. The observation of bright blue fluorescence indicated that more phenolic compounds accumulated in the cells under UV light, extracts from tobacco cells and their culture filtrate showed strong accumulation of scopoletin within 48 h after treatment, and reached a peak at 12 h after treatment. Lignin deposition strongly increased by 1.5 and 1.8 times respectively at 24 and 48 h after elicitation when compared with the control. 【Conclusion】 These results suggest that the increase in related enzymes, phenolic compounds and lignin was induced by riboflavin in tobacco suspension cells.