FLAVONOID AND ISOFLAVONOID DISTRIBUTION IN DEVELOPING SOYBEAN SEEDLING TISSUES AND IN SEED AND ROOT EXUDATES
FLAVONOID AND ISOFLAVONOID DISTRIBUTION IN DEVELOPING SOYBEAN SEEDLING TISSUES AND IN SEED AND ROOT EXUDATES
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DOI：
10.1104/pp.95.2.594
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发表时间：
1991-02-01
期刊：
影响因子：
7.4
通讯作者：
GRAHAM, TL
中科院分区：
文献类型：
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作者：
GRAHAM, TL
研究了黄酮类、异黄酮类及其结合物在大豆发育过程中的分布。对幼苗器官、根和种子分泌物进行了检查。大豆异黄酮和染料木素的结合物是干种子内所有胚胎器官以及萌发后幼苗根、下胚轴和子叶组织中的主要代谢物。初生叶组织萌发后3天开始从异黄酮类代谢向类黄酮类代谢转变，5天后主要由黄酮醇、康普菲醇、栎素和异鼠李素的糖苷组成。子叶含有相对恒定且非常高水平的大豆苷元和染料木素的结合物。下胚轴组织含有第三种未知化合物，P19.3，也以多种结合形式存在。大豆苷元、染料木素和P19.3的结合物在下胚轴中处于最高水平，并沿着下胚轴逐渐脱落。这些异黄酮在下胚轴挂钩中也经历了2到4天的程序性和戏剧性的减少。所有的根段都以大豆苷元及其结合物为主，特别是在根尖，它们在幼苗中达到最高水平。光照对异黄酮类成分的分布有明显的影响，黑暗条件下，根尖中的异黄酮含量显著降低，而子叶中的异黄酮含量较高。最后，大豆苷元和染料木素的结合物以及几种未知的芳香族代谢物被选择性地排泄到根和种子分泌物中。对种子分泌物的分析表明，这是一个连续但可饱和的事件。
The distribution of flavonoids, isoflavonoids, and their conjugates in developing soybean (Glycine max L.) seedling organs and in root and seed exudates has been examined. Conjugates of the isoflavones daidzein and genistein are major metabolites in all embryonic organs within the dry seed and in seedling roots, hypocotyl, and cotyledon tissues at all times after germination. Primary leaf tissues undergo a programmed shift from isoflavonoid to flavonoid metabolism 3 days after germination and become largely predominated by glycosides of the flavonols kampferol, quercetin, and isorhamnetin by 5 days. Cotyledons contain relatively constant and very high levels of conjugates of both daidzein and genistein. Hypocotyl tissues contain a third unidentified compound, P 19.3, also present in multiple conjugated forms. Conjugates of daidzein, genistein, and P19.3 are at their highest levels in the hypocotyl hook and fall off progressively down the hypocotyl. These isoflavones also undergo a programmed and dramatic decrease between 2 and 4 days in the hypocotyl hook. All root sections are predominated by daidzein and its conjugates, particularly in the root tip, where they reach the highest levels in the seedling. Light has a pronounced effect on the distribution of the isoflavones; in the dark, isoflavone levels in the root tips are greatly reduced, while those in the cotyledons are higher. Finally, the conjugates of daidzein and genistein and several unidentified aromatic metabolites are selectively excreted into root and seed exudates. Analysis of seed exudates suggests that this is a continuous, but saturable event.