锗对霍山石斛类原球茎悬浮培养细胞生长和多糖合成及氧化还原态的影响

Effects of germanium on cell growth,polysaccharide production and cellular redox status in suspension cultures of protocorm-like bodies of Dendrobium huoshanense

为解决霍山石斛类原球茎液体培养细胞生长缓慢和代谢水平低下的问题,研究了不同浓度的锗(GeO2)对霍山石斛类原球茎增殖、多糖合成及碳氮利用的影响,分析了类原球茎细胞内还原糖、可溶性蛋白质含量、抗氧化酶活性以及细胞氧化还原态的变化。结果表明,适当浓度的二氧化锗(4.0mg/L)显著促进霍山石斛类原球茎的增殖和多糖的积累,最大细胞干重为32.6g/L,最大多糖产量为3.78g/L;显著提高胞内还原糖和可溶性蛋白质含量,超氧化物歧化酶和过氧化氢酶的活性明显升高,而过氧化物酶的活性则有所降低;氧化还原态分析发现,二氧化锗处理的细胞内还原型谷胱甘肽/氧化型谷胱甘肽的值明显提高,谷胱甘肽还原酶活性升高。添加适量的二氧化锗有利于细胞生长和多糖合成。

To solve the problem of low growth rate and metabolism level in suspension cultures of protocorm-like bodies （PLBs） of Dendrobium huoshanense. The effects of germanium on PLB proliferation and accumulation of polysaccharides together with nutrient utilization were investigated and the contents of reducing sugars, soluble proteins, the activities of antioxidant enzymes and redox status of the cells of PLB were analyzed. The results indicated that the optimum concentration of germanium dioxide （4.0 mg/L） significantly enhanced the cell growth and accumulation of polysaccharides, greatly improved contents of reducing sugars and soluble proteins, increased the activities of superoxide dismutase （SOD） and catalase （CAT） but decreased the activity of peroxidase（POD）. The cell dry weight and production of polysaccharides were 32.6 g/L and 3.78 g/L, respectively. The analysis of cellular redox status showed that the ratio of reduced glutathione （GSH） to oxidized glutathione （GSSG） in cells and the activity of glutathione reductase were significantly increased by the addition of germanium dioxide. The suitable concentration of germanium dioxide was beneficial to the cell growth and the accumulation of polysaccharides.