Soluble carbohydrates in Delphinium and their influence on sepal abscission in cut flowers
Soluble carbohydrates in Delphinium and their influence on sepal abscission in cut flowers
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DOI：
10.1034/j.1399-3054.2000.108003307.x
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发表时间：
2000-03-01
影响因子：
6.4
通讯作者：
Goto, R
中科院分区：
文献类型：
--
作者：
Ichimura, K;Kohata, K;Goto, R
除蔗糖、葡萄糖、果糖和肌醇外，在飞燕草的花瓣提取物中还检测到一种碳水化合物。该化合物经H-1-核磁共振鉴定为甘露醇，甘露醇是所有器官中的主要碳水化合物：花瓣、花的其他部分、茎和叶、甘露醇和葡萄糖(均为0.55M)喂食切花的飞燕草，同样延迟了花瓣的脱落。相同摩尔浓度的3-O-甲基葡萄糖(3-OMG)和聚乙二醇200无此作用。在不改变蔗糖和甘露醇浓度的情况下，葡萄糖处理显著增加了花被中葡萄糖和果糖的浓度，而甘露醇处理则增加了花被中除甘露醇外的葡萄糖和果糖的浓度，这表明甘露醇在飞燕草花中是代谢的。3-OMG处理增加了3-OMG的浓度，但没有增加其他碳水化合物的浓度，甘露醇和葡萄糖同样延缓了花中乙烯产生的增加，但3-OMG没有。葡萄糖和甘露醇处理对乙烯的敏感性同样降低，但3-OMG没有降低。这些结果表明，甘露醇处理通过降低对乙烯的敏感性而延迟了飞燕草的裂片脱落，甘露醇不仅作为渗透调节剂，而且是碳水化合物代谢的明显来源。
A carbohydrate other than sucrose, glucose, fructose and myo-inositol was detected in sepal extracts of Delphinium. This compound was identified as mannitol by H-1-NMR, Mannitol was the major carbohydrate in all examined organs: the sepal, the other parts of the flower, the stem and leaves, Mannitol as well as glucose (both at 0.55 M), fed to cut Delphinium flowers, similarly delayed the abscission of sepals. 3-O-methyl glucose (3-OMG) and polyethylene glycol 200 at the same molar concentrations had no such effect. The treatment with glucose markedly increased the concentrations of glucose and fructose in the sepals without changing the concentrations of sucrose and mannitol, On the other hand, the treatment with mannitol increased the concentrations of glucose and fructose in addition to mannitol in the sepals, suggesting that mannitol is metabolized in Delphinium flowers. The treatment with 3-OMG increased the concentration of 3-OMG but not other carbohydrates, Mannitol and glucose similarly delayed the increase in ethylene production in flowers, but 3-OMG did not. The sensitivity to ethylene was similarly reduced by the treatment with glucose and mannitol, but not by 3-OMG, These results suggest that the treatment with mannitol, a major carbohydrate in Delphinium, delayed the abscission of sepals by reducing the sensitivity to ethylene, Mannitol further acted, not merely as an osmolyte, but as an apparent source for carbohydrate metabolism in the flower.