Characterization, localization, and seasonal changes of the sucrose transporter FeSUT1 in the phloem of Fraxinus excelsior.

ABSTRACT: Trees are generally assumed to be symplastic phloem loaders. A typical feature for most wooden species is an open minor vein structure with symplastic connections between mesophyll cells and phloem cells, which allow sucrose to move cell-to-cell through the plasmodesmata into the phloem. Fraxinus excelsior (Oleaceae) also translocates raffinose family oligosaccharides in addition to sucrose. Sucrose concentration was recently shown to be higher in the phloem sap than in the mesophyll cells. This suggests the involvement of apoplastic steps and the activity of sucrose transporters in addition to symplastic phloem-loading processes. In this study, the sucrose transporter FeSUT1 from F. excelsior was analysed. Heterologous expression in baker's yeast showed that FeSUT1 mediates the uptake of

SUBMITTER: Oner-Sieben S 

PROVIDER: S-EPMC4507781 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature