Analysis of sugars in squash xylem sap
Analysis of sugars in squash xylem sap
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DOI：
10.1093/pcp/pcg075
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发表时间：
2003-06-01
影响因子：
4.9
通讯作者：
Satoh, S
中科院分区：
文献类型：
--
作者：
Iwai, H;Usui, M;Satoh, S
木质部汁液含有可能参与根与芽通讯的有机和无机化合物。为了阐明木质部汁液中糖的生理功能，我们表征了木质部汁液中的糖化合物。木质部汁液的80%乙醇可溶部分主要含有肌醇和低聚糖。用环己二胺四乙酸酯溶解80%乙醇沉淀物，并使用阴离子交换色谱法进行分馏。来自阴离子交换柱的未结合级分与Yariv试剂反应，并且富含阿拉伯半乳聚糖，表明存在阿拉伯半乳聚糖蛋白（AGP）。结合的级分用50 mM甲酸铵缓冲液洗脱，并使用尺寸排阻色谱法分离，产生表观分子量分别为15，000和11，000的果胶鼠李糖半乳糖醛酸（RG）-I和RG-II。这些结果表明，根组织产生的AGP，RG-I，硼酸盐交联的RG-II二聚体和寡糖通过木质部汁液运输到地上器官。
Xylem sap contains organic and inorganic compounds that might be involved in root-to-shoot communication. To clarify the physiological functions of sugars in xylem sap, we characterized the sugar compounds of the xylem sap. The 80% ethanol-soluble fraction of xylem sap contained mainly myo-inositol and oligosaccharides. The 80% ethanol precipitate was solubilized with cyclohexanediamine tetraacetate and fractionated using anion exchange chromatography. The non-bound fraction from the anion-exchange column reacted with Yariv reagent and was rich in arabinogalactan, indicating the presence of arabinogalactan proteins (AGP). The bound fraction eluted with 50 mM ammonium formate buffer and separated using size exclusion chromatography producing the pectins rhamnogaracturonan (RG)-l and RG-II with apparent molecular masses of 15,000 and 11,000, respectively. These results indicate that the AGP, RG-I, borate cross-linked RG-II dimer and oligosaccharides produced by root tissues are transported to above-ground organs via xylem sap.