Abstract

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.

Published in

Science
2004, Volume: 303, number: 5654, pages: 87-89
Publisher: AMER ASSOC ADVANCEMENT SCIENCE AMER ASSOC ADVANCEMENT SCIENCE

UKÄ Subject classification

Botany


Publication identifier

DOI: https://doi.org/10.1126/science.1091811

Permanent link to this page (URI)

https://res.slu.se/id/publ/42694