A previously unknown maltose transporter essential for starch degradation in leaves
A previously unknown maltose transporter essential for starch degradation in leaves
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DOI：
10.1126/science.1091811
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发表时间：
2004-01-02
期刊：
影响因子：
56.9
通讯作者：
Zeeman, SC
中科院分区：
文献类型：
--
作者：
Niittylä, T;Messerli, G;Zeeman, SC
一个以前未知的麦芽糖转运体是必不可少的淀粉转化为蔗糖在夜间拟南芥叶片。通过分离两个高淀粉水平和非常高麦芽糖（淀粉分解的中间物）的等位突变体来鉴定转运体。这些突变影响了先前未知功能的基因MEX1。我们发现MEX1是一种麦芽糖转运蛋白，与其他糖转运蛋白无关。严重的mex1表型表明，mex1是夜间叶绿体输出碳水化合物的主要途径。水稻和马铃薯等植物的同源基因表明麦芽糖输出具有广泛的意义。
A previously unknown maltose transporter is essential for the conversion of starch to sucrose in Arabidopsis leaves at night. The transporter was identified by isolating two allelic mutants with high starch levels and very high maltose, an intermediate of starch breakdown. The mutations affect a gene of previously unknown function, MEX1. We show that MEX1 is a maltose transporter that is unrelated to other sugar transporters. The severe mex1 phenotype demonstrates that MEX1 is the predominant route of carbohydrate export from chloroplasts at night. Homologous genes in plants including rice and potato indicate that maltose export is of widespread significance.