Dept. of General Botany, Swiss Federal Institute of Technology, Sonneggstraβe 5, CH-8092 Zürich.
J Plant Physiol. 1985 Mar;118(3):237-49. doi: 10.1016/S0176-1617(85)80225-X. Epub 2012 Jan 2.
Protoplasts from the mesophyll of barley primary leaves glycosilate and accumulate exogenous coumarin-aglycons such as scopoletin and esculetin. The corresponding glycosides are ultimately compartmentalized in the vacuoles. Glycosilation of the aglycons and accumulation of glycosides are markedly enhanced by light. The activity of UDP-glucose: esculetin glycosyltransferase is located in the cytosol. Isolated vacuoles take up the glucoside esculin. Transport across the tonoplast is dependent on ATP, is characterized by its saturation kinetics (K(m) = 0.22 mM), and is inhibited by the protonophore CCCP. A model for glycoside transport across the tonoplast and retention in the cell sap is proposed.
大麦幼叶叶肉原生质体能够糖基化并积累外源性香豆素苷元，如东莨菪素和七叶苷。相应的糖苷最终被分隔在液泡中。糖基化和糖苷积累明显受光照增强。UDP-葡萄糖：七叶苷糖苷基转移酶的活性位于细胞质溶胶中。分离的液泡摄取糖苷七叶苷。穿过液泡膜的运输依赖于 ATP，其特征在于其饱和动力学（K(m)=0.22mM），并受质子载体 CCCP 抑制。提出了一种穿过液泡膜和保留在细胞溶质中的糖苷运输模型。
