液泡
普通大麦
反转运蛋白
生物化学
拟南芥
芹菜素
异牡荆素
葡萄糖苷
生物
拟南芥
ATP结合盒运输机
叶绿体
运输机
突变体
类黄酮
植物
禾本科
基因
细胞质
膜
牡荆素
抗氧化剂
医学
替代医学
病理
作者
Nathalie Frangne,Thomas Eggmann,Carsten Koblischke,Gottfried Weissenböck,Enrico Martinoia,Markus Klein
出处
期刊:Plant Physiology
[Oxford University Press]
日期:2002-02-01
卷期号:128 (2): 726-733
被引量:120
摘要
Abstract In many cases, secondary plant products accumulate in the large central vacuole of plant cells. However, the mechanisms involved in the transport of secondary compounds are only poorly understood. Here, we demonstrate that the transport mechanisms for the major barley (Hordeum vulgare) flavonoid saponarin (apigenin 6-C-glucosyl-7-O-glucoside) are different in various plant species: Uptake into barley vacuoles occurs via a proton antiport and is competitively inhibited by isovitexin (apigenin 6-C-glucoside), suggesting that both flavone glucosides are recognized by the same transporter. In contrast, the transport into vacuoles from Arabidopsis, which does not synthesize flavone glucosides, displays typical characteristics of ATP-binding cassette transporters. Transport of saponarin into vacuoles of both the species is saturable with a K m of 50 to 100 μm. Furthermore, the uptake of saponarin into vacuoles from a barley mutant exhibiting a strongly reduced flavone glucoside biosynthesis is drastically decreased when compared with the parent variety. Thus, the barley vacuolar flavone glucoside/H+antiporter could be modulated by the availability of the substrate. We propose that different vacuolar transporters may be responsible for the sequestration of species-specific/endogenous and nonspecific/xenobiotic secondary compounds in planta.
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