DISTRIBUTION AND UTILIZATION OF CHLOROGENIC ACID IN COFFEA SEEDLINGS
DISTRIBUTION AND UTILIZATION OF CHLOROGENIC ACID IN COFFEA SEEDLINGS
复制标题
DOI：
10.1093/jxb/45.4.497
复制
发表时间：
1994-04-01
影响因子：
6.9
通讯作者：
BAUMANN, TW
中科院分区：
文献类型：
--
作者：
AERTS, RJ;BAUMANN, TW
成熟的咖啡种子(Coffea arabica L.)含有大量的嘌呤、生物碱、咖啡因和多酚绿原酸(5-O-咖啡酰奎宁酸)。萌发后，这两种化合物几乎只在子叶和周围的胚乳中恢复，而在咖啡幼苗的下胚轴和根中几乎没有。在发育的前10周，子叶侵入胚乳并膨大。发育中的子叶咖啡因含量变化不大，绿原酸含量下降到原来的1/3。绿原酸的损失在幼苗的其他器官中没有恢复。绿原酸含量的下降与发育中的子叶中细胞壁结合的酚类聚合物的数量增加相一致，这些酚类聚合物可以在硫代乙醇酸衍生化后提取。在发育中的子叶中，几乎检测不到苯丙氨酸解氨酶(PAL)活性。这些结果表明，咖啡种子中储存的绿原酸在扩张过程中被用来在子叶细胞壁中沉积酚类聚合物，可能是木质素。子叶中的情况与叶片中的情况明显相反：小叶中的PAL活性是子叶的900倍。在小叶中，绿原酸和咖啡因在叶片展开过程中不断积累。
Ripe coffee seeds (Coffea arabica L.) contain large quantities of the purine alkaloid caffeine and the depside chlorogenic acid (5-O-caffeoyl-quinic acid). Directly after germination, both compounds were recovered almost exclusively in the cotyledons and surrounding endosperm and hardly at all in the hypocotyl and root of coffee seedlings. During the first 10 weeks of development, the cotyledons invaded the endosperm and expanded. The caffeine content in the developing cotyledons changed little, but the chlorogenic acid content dropped to one-third of the original level. The loss of chlorogenic acid was not recovered in the other organs of the seedling. The drop in chlorogenic acid content coincided with an increase in the amount of cell wall-bound phenolic polymers in the developing cotyledons, which could be extracted after thioglycolic acid derivatization. In the developing cotyledons, phenylalanine ammonia lyase (PAL) activity was hardly detectable. These results suggest that the chlorogenic acid stored in coffee seeds is used for the deposition of phenolic polymers, presumably lignin, in cotyledonary cell walls during expansion. The situation in cotyledons was found to be in marked contrast to that in foliage: leaflets, in which PAL activity was 900-fold higher than in cotyledons. In the leaflets, both chlorogenic acid and caffeine accumulated continuously during leaf expansion.