寡聚糖诱导悬浮培养红豆杉细胞生理态势的改变

运用顺磁共振、电镜、能谱等手段研究了寡聚糖对红豆杉细胞氧化还原生理态势的影响 .结果表明 ,诱导前红豆杉细胞处于相对稳定的生长态势 ,细胞完整 ,细胞器发达 ;氧化还原电势较低 ,活性氧相关酶系统相对稳定 ,细胞初生代谢旺盛 ,紫杉醇合成速率很低 .诱导后红豆杉细胞向产物合成态势转移 ,SOD酶活性迅速提高 ,CAT和POD酶活被强烈抑制 ;细胞出现活性氧迸发 ,4h达最大值 ;细胞的氧化还原电势增高 ,细胞膜上离子通道被激活 ,H⁺ 和Ca^{2 +} 内流 ,Cl^-外流 ;液胞内出现大量含Ca^{2 +} 离子的高电子致密区并呈规律性变化 ,培养环境碱化 ;细胞生长被抑制 ,紫杉醇合成速率升高 ,其产量提高了 5.5倍 ,达 76.1mg·L^-1.

CHANGES OF PHYSIOLOGICAL STATE OF SUSPENSION CULTURES OF Taxus chenensis var. mairei INDUCED BY OLIGOSACCHARIDE

By electron paramagnetic resonance spectroscopy, electron microscopy and energy spectrum, the transferring of physiological state of cells was studied when oligosaccharide from Fusarium oxysprum was added in suspension cultures of Taxus chenensis var. mairei. Cells before elicitation were in a good state of growth including integration of cells, abundance of organelle, stability of active oxygen system, low redox potential of cells,flourishing of primary metabolism and low rate of taxol biosynthesis. After elicitation the activity of superoxide dismutase was improved sharply at first, and the activity of catalase and peroxidase were inhibited severely, then the oxidative burst was caused in cells and reached a maximum at 4h. The redox potential of cells was promoted rapidly, and ion channels in cell membrane were activated leading to H ⁺, Ca ²⁺ influx and Cl ^- efflux which caused alkalization of medium. The observation by using optical microcopy and transmission electron microscopy showed that the high electron density body including Ca ²⁺ in vacuole changed regularly. Cell growth was inhibited, but productivity of taxol was increased 5.5 fold of that of control (76.1mg·L ^-1 ) and the system became the state of product synthesis.