The effects of neodymium nitrate （Nd^3＋） on the adventitious rooting of Dendrobium densiflorum shoot cuttings were studied. The addition of Nd^3＋ （5 μmol/L） to culture medium significantly increased rooting fre...The effects of neodymium nitrate （Nd^3＋） on the adventitious rooting of Dendrobium densiflorum shoot cuttings were studied. The addition of Nd^3＋ （5 μmol/L） to culture medium significantly increased rooting frequency. Histological investigation showed that Nd^3＋ did not change the process of root initiation. Nd^3＋ did not influence total endogenous cytokinin levels, but significantly increased the level of endogenous indole-3-acetic acid （IAA） in the base of shoot cuttings. Compared to the control, the ratio of IAA/cytokinins was very high in the Nd^3＋ treatment. These results suggested that the enhanced rooting frequency may be related to the increase in endogenous IAA level in Nd^3＋ treatment. Analysis of enzyme activities showed that the enhanced accumulation of the endogenous IAA by Nd^3＋ should not be attributed to inhibition of IAA decomposition by IAA oxidase or promotion of cytokinin decomposition by cytokinin oxidase. Besides, Nd^3＋ increased the ratio of reduced glutathione （GSH） and oxidized glutathione （GSSG） in the process of adventitious rooting while the ratio of ascorbate （ASC） to dehydroascorbate （DHA） was not affected.展开更多
A new picrotoxane type sesquiterpene named dendrodensiflorol has been isolated from the stems of Dendrobium densiflorum. Its structure was identified on the basis of spectroscopic method.
以密花石斛(Dendrobium densiflorum Lindley ex Wallich)为研究试材,对植物SDS方法提取基因组DNA中的若干影响因子诸如药品、试剂配制方法、DNA取材部位、蛋白质去除次数、DNA析出时间、提取样品水浴时间等进行了比较分析。结果表明:...以密花石斛(Dendrobium densiflorum Lindley ex Wallich)为研究试材,对植物SDS方法提取基因组DNA中的若干影响因子诸如药品、试剂配制方法、DNA取材部位、蛋白质去除次数、DNA析出时间、提取样品水浴时间等进行了比较分析。结果表明:不同的SDS缓冲液配制方法提取效果差异较大,Wang's配方产率及纯度都较高;石斛花苞的DNA提取产率较叶片高,但纯度较叶片低;提取过程中,适宜的水浴时间当为30～40min,过短DNA产率下降,过长会引起DNA的降解,或最后产物中增加其他杂质;氯仿/异戊醇抽提次当为2～3次,对去除DNA中蛋白质、多糖及其它杂质有一定的作用,过多则DNA损失也明显;异丙醇沉淀时间10min时核酸析出量在80%以上,纯度相对较高,继续沉淀的产物中DNA含量及纯度明显变低,同时采取挑取絮状沉淀或再用无水乙醇纯化10min的方法,可减少蛋白质、多糖等其它杂质的影响。展开更多
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China (20060359006)
文摘The effects of neodymium nitrate （Nd^3＋） on the adventitious rooting of Dendrobium densiflorum shoot cuttings were studied. The addition of Nd^3＋ （5 μmol/L） to culture medium significantly increased rooting frequency. Histological investigation showed that Nd^3＋ did not change the process of root initiation. Nd^3＋ did not influence total endogenous cytokinin levels, but significantly increased the level of endogenous indole-3-acetic acid （IAA） in the base of shoot cuttings. Compared to the control, the ratio of IAA/cytokinins was very high in the Nd^3＋ treatment. These results suggested that the enhanced rooting frequency may be related to the increase in endogenous IAA level in Nd^3＋ treatment. Analysis of enzyme activities showed that the enhanced accumulation of the endogenous IAA by Nd^3＋ should not be attributed to inhibition of IAA decomposition by IAA oxidase or promotion of cytokinin decomposition by cytokinin oxidase. Besides, Nd^3＋ increased the ratio of reduced glutathione （GSH） and oxidized glutathione （GSSG） in the process of adventitious rooting while the ratio of ascorbate （ASC） to dehydroascorbate （DHA） was not affected.
文摘A new picrotoxane type sesquiterpene named dendrodensiflorol has been isolated from the stems of Dendrobium densiflorum. Its structure was identified on the basis of spectroscopic method.
文摘以密花石斛(Dendrobium densiflorum Lindley ex Wallich)为研究试材,对植物SDS方法提取基因组DNA中的若干影响因子诸如药品、试剂配制方法、DNA取材部位、蛋白质去除次数、DNA析出时间、提取样品水浴时间等进行了比较分析。结果表明:不同的SDS缓冲液配制方法提取效果差异较大,Wang's配方产率及纯度都较高;石斛花苞的DNA提取产率较叶片高,但纯度较叶片低;提取过程中,适宜的水浴时间当为30～40min,过短DNA产率下降,过长会引起DNA的降解,或最后产物中增加其他杂质;氯仿/异戊醇抽提次当为2～3次,对去除DNA中蛋白质、多糖及其它杂质有一定的作用,过多则DNA损失也明显;异丙醇沉淀时间10min时核酸析出量在80%以上,纯度相对较高,继续沉淀的产物中DNA含量及纯度明显变低,同时采取挑取絮状沉淀或再用无水乙醇纯化10min的方法,可减少蛋白质、多糖等其它杂质的影响。
