目的建立HPAEC-PAD法测定霍山石斛Dendrobium huoshanense C. Z. Tang et S. J. Cheng中甘露糖、葡萄糖、果糖、半乳糖、阿拉伯糖、木糖的含有量。方法依次采用超声处理、水解和氮气吹干法制备供试品溶液。氢氧化钠/醋酸钠溶液梯度洗脱...目的建立HPAEC-PAD法测定霍山石斛Dendrobium huoshanense C. Z. Tang et S. J. Cheng中甘露糖、葡萄糖、果糖、半乳糖、阿拉伯糖、木糖的含有量。方法依次采用超声处理、水解和氮气吹干法制备供试品溶液。氢氧化钠/醋酸钠溶液梯度洗脱;温度30℃;电极材料Au;参比电极pH-Ag/AgCl;电位波形糖四电位;体积流量0.45 mL/min。结果甘露糖、葡萄糖、果糖、半乳糖、阿拉伯糖、木糖在各自范围内线性关系良好(r>0.990 0),平均加样回收率分别为93.4%、92.3%、93.7%、106.1%、94.1%、103.7%,RSD分别为2.1%、1.7%、3.3%、1.2%、4.5%、1.7%。结论该方法稳定性好,灵敏度高,可用于霍山石斛的质量控制。展开更多
Changes in glutathione and ascorbate content, hydrogen peroxide and abscisic acid were studied in developing leaves in wild-type (Col-0) and glutathione-deficient mutant pad2-1 lines of Arabidopsis thaliana over a tim...Changes in glutathione and ascorbate content, hydrogen peroxide and abscisic acid were studied in developing leaves in wild-type (Col-0) and glutathione-deficient mutant pad2-1 lines of Arabidopsis thaliana over a time period of 9 days of drought followed by re-watering. Glutathione deficient mutant (pad2-1) presents mechanisms of acclimation to water stress through the reduction of plant biomass and increase in endogenous concentrations of ascorbate and glutathione. These acclimation responses to stress appeared along with the first symptoms of stress and we suggest here that they are regulated by ABA and H<sub>2</sub>O<sub>2</sub>. Normally, wild type plants under conditions of stress require an initial response phase in which a decrease in antioxidants is observed before reaching acclimation through the increase in levels of antioxidants. pad2-1 is more sensitive to stress and reacts to it;however, it did not suffer more oxidative stress than Col-0 plants, even though pad2-1 had higher levels of endogenous H<sub>2</sub>O<sub>2</sub> relative to wild-type. In both water stressed Col-0 and pad2-1 plants increases in ABA were observed, however, more sharply in wild-type stressed plants. Low levels of glutathione together with high levels of H<sub>2</sub>O<sub>2</sub> may regulate endogenous ABA concentrations and could be related to the slow growth rates which were observed during the experiment. The results highlighted the double function of glutathione as an antioxidant and signal molecule and also, the different response patterns of wild-type and pad2-1 when faced with drought stress. The results bring new insights to the responses of pad2-1 under conditions of water stress.展开更多
文摘目的建立HPAEC-PAD法测定霍山石斛Dendrobium huoshanense C. Z. Tang et S. J. Cheng中甘露糖、葡萄糖、果糖、半乳糖、阿拉伯糖、木糖的含有量。方法依次采用超声处理、水解和氮气吹干法制备供试品溶液。氢氧化钠/醋酸钠溶液梯度洗脱;温度30℃;电极材料Au;参比电极pH-Ag/AgCl;电位波形糖四电位;体积流量0.45 mL/min。结果甘露糖、葡萄糖、果糖、半乳糖、阿拉伯糖、木糖在各自范围内线性关系良好(r>0.990 0),平均加样回收率分别为93.4%、92.3%、93.7%、106.1%、94.1%、103.7%,RSD分别为2.1%、1.7%、3.3%、1.2%、4.5%、1.7%。结论该方法稳定性好,灵敏度高,可用于霍山石斛的质量控制。
文摘Changes in glutathione and ascorbate content, hydrogen peroxide and abscisic acid were studied in developing leaves in wild-type (Col-0) and glutathione-deficient mutant pad2-1 lines of Arabidopsis thaliana over a time period of 9 days of drought followed by re-watering. Glutathione deficient mutant (pad2-1) presents mechanisms of acclimation to water stress through the reduction of plant biomass and increase in endogenous concentrations of ascorbate and glutathione. These acclimation responses to stress appeared along with the first symptoms of stress and we suggest here that they are regulated by ABA and H<sub>2</sub>O<sub>2</sub>. Normally, wild type plants under conditions of stress require an initial response phase in which a decrease in antioxidants is observed before reaching acclimation through the increase in levels of antioxidants. pad2-1 is more sensitive to stress and reacts to it;however, it did not suffer more oxidative stress than Col-0 plants, even though pad2-1 had higher levels of endogenous H<sub>2</sub>O<sub>2</sub> relative to wild-type. In both water stressed Col-0 and pad2-1 plants increases in ABA were observed, however, more sharply in wild-type stressed plants. Low levels of glutathione together with high levels of H<sub>2</sub>O<sub>2</sub> may regulate endogenous ABA concentrations and could be related to the slow growth rates which were observed during the experiment. The results highlighted the double function of glutathione as an antioxidant and signal molecule and also, the different response patterns of wild-type and pad2-1 when faced with drought stress. The results bring new insights to the responses of pad2-1 under conditions of water stress.
基金The project supported in part by National Natural Science Foundation of China under Grant No. 10205004 .Acknowledgments The authors are grateful to Dr. E. Epelbaum for helpful communications. J.F. Yang is grateful to Prof. B.A. Kniehl for his hospitality at the II. Institute for Theoretical Physics of Hamburg University where part of this work was done.
