Agrobacterium tumefaciens AK-6b gene modulates phenolic compound metabolism in tobacco
Agrobacterium tumefaciens AK-6b gene modulates phenolic compound metabolism in tobacco
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DOI：
10.1016/j.phytochem.2003.10.015
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发表时间：
2004-01-01
期刊：
影响因子：
3.8
通讯作者：
Wabiko, H
中科院分区：
文献类型：
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作者：
Gális, I;Kakiuchi, Y;Wabiko, H
根癌农杆菌AKE 10的6 b基因（AK-6 b）可以替代烟草组织对生长素和细胞分裂素的需求，以维持愈伤组织在培养基中的生长。为了鉴定可能参与这一过程的化合物，我们分析了表达AK-6 b基因的转基因烟草组织中的酚类代谢物。在含有细胞分裂素和生长素的培养基（SH培养基）上，转基因愈伤组织比野生型组织积累了更高水平的绿原酸、咖啡酰腐胺、芦丁和山奈酚-3-芸香糖苷。与此相反，东莨菪碱及其苷元、东莨菪碱内酯在转基因组织中的水平较低。在无酶培养基上，这些酚类化合物与AK-6 b转录水平无显著相关性，但东莨菪内酯与AK-6 b转录水平呈负相关。显然，AK-6 b基因在SH培养基中起作用，将烟草组织中东莨菪碱的合成重定向到咖啡酸衍生物和黄酮类化合物的优先合成。(C)2003 Elsevier Ltd.保留所有权利。
The 6b gene (AK-6b) of Agrobacterium tumefaciens AKE10 can substitute for the requirement of tobacco tissues for auxin and cytokinin to maintain callus growth in the culture medium. To identify compounds that might be involved in this process we analyzed phenolic metabolites in transgenic tobacco tissues expressing the AK-6b gene. On medium containing both cytokinin and auxin (SH medium), transgenic calli accumulated higher levels of chlorogenic acid, caffeoyl putrescine, rutin and kaempferol-3-rutinoside, than did wild-type tissues. In contrast, the levels of scopolin and its aglycone, scopoletin were lower in transgenic tissues. On hormone-free medium, these phenolic compounds showed neither significant levels nor an apparent relationship with AK-6b transcript levels, except for the negatively correlated levels of scopoletin and AK-6b transcripts. Apparently, the AK-6b gene acts, in SH medium, to redirect the synthesis of scopolin in tobacco tissues towards the preferential synthesis of caffeic acid derivatives and flavonoids. (C) 2003 Elsevier Ltd. All rights reserved.