Distribution of free and glycosylated sterols within Cycas micronesica plants.
Distribution of free and glycosylated sterols within Cycas micronesica plants.
复制标题
密克罗尼西亚苏铁植物内游离和糖基化甾醇的分布。
DOI：
10.1016/j.scienta.2009.11.009
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发表时间：
2010
影响因子：
4.3
通讯作者：
Shaw,ChristopherA
中科院分区：
文献类型：
--
作者：
Marler,ThomasE;Shaw,ChristopherA
从苏铁种子中提取的面粉曾经是关岛居民淀粉的主要来源。苏铁的食用与人类神经退行性疾病的高发有关。我们确定了甾醇和β-谷甾醇及其衍生的葡萄糖苷在不同植物部位的分布，因为它们已在苏铁粉中被鉴定出来，并已被证明会引起神经退行性结果。这四种化合物在种子、孢子叶、花粉、叶、茎和根中都很常见。根中这两种游离甾醇含量最高，光合作用的小叶组织中这两种甾醇苷含量最高。与其他器官相比，三种茎组织类别中的浓度较低。生殖孢子叶组织中游离甾醇含量与种子相似，但甾醇苷含量高于种子。花粉中缺少一种糖苷。如前所述，幼种子的浓度高于老种子，但在叶、孢子叶和维管组织的年龄类别中，浓度没有差异。这些器官内不同组织之间的轮廓差异可能有助于阐明这些化合物的生理作用。
Flour derived from Cycas micronesica seeds was once the dominant source of starch for Guam's residents. Cycad consumption has been linked to high incidence of human neurodegenerative diseases. We determined the distribution of the sterols stigmasterol and β-sitosterol and their derived glucosides stigmasterol β-d-glucoside and β-sitosterol β-d-glucoside among various plant parts because they have been identified in cycad flour and have been shown to elicit neurodegenerative outcomes. All four compounds were common in seeds, sporophylls, pollen, leaves, stems, and roots. Roots contained the greatest concentration of both free sterols, and photosynthetic leaflet tissue contained the greatest concentration of both steryl glucosides. Concentration within the three stem tissue categories was low compared to other organs. Reproductive sporophyll tissue contained free sterols similar to seeds, but greater concentration of steryl glucosides than seeds. One of the glucosides was absent from pollen. Concentration in young seeds was higher than old seeds as reported earlier, but concentration did not differ among age categories of leaf, sporophyll, or vascular tissue. The profile differences among the various tissues within these organs may help clarify the physiological role of these compounds.