title: Diversity and activity of sugar transporters in nematode-induced root syncytia.
abstract: The plant-parasitic nematode Heterodera schachtii stimulates plant root cells to form syncytial feeding structures which synthesize all nutrients required for successful nematode development. Cellular re-arrangements and modified metabolism of the syncytia are accompanied by massive intra- and intercellular solute allocations. In this study the expression of all genes annotated as sugar transporters in the Arabidopsis Membrane Protein Library was investigated by Affymetrix gene chip analysis in young and fully developed syncytia compared with non-infected Arabidopsis thaliana roots. The expression of three highly up-regulated (STP12, MEX1, and GTP2) and three highly down-regulated genes (SFP1, STP7, and STP4) was analysed by quantitative RT-PCR (qRT-PCR). The most up-regulated gene (STP12) was chosen for further in-depth studies using in situ RT-PCR and a nematode development assay with a T-DNA insertion line revealing a significant reduction of male nematode development. The specific role of STP12 expression in syncytia of male juveniles compared with those of female juveniles was further shown by qRT-PCR. In order to provide evidence for sugar transporter activity across the plasma membrane of syncytia, fluorescence-labelled glucose was used and membrane potential recordings following the application of several sugars were performed. Analyses of soluble sugar pools revealed a highly specific composition in syncytia. The presented work demonstrates that sugar transporters are specifically expressed and active in syncytia, indicating a profound role in inter- and intracelluar transport processes.
authors.affiliation: Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, BOKU-University of Natural Resources and Applied Life Sciences Vienna, Peter Jordan-Str. 82, A-1190 Vienna, Austria.
authors.forename: Julia
authors.initials: J
authors.lastname: Hofmann
authors.forename: Paul H
authors.initials: PH
authors.lastname: Hess
authors.forename: Dagmar
authors.initials: D
authors.lastname: Szakasits
authors.forename: Andreas
authors.initials: A
authors.lastname: Blöchl
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Wieczorek
authors.forename: Sabine
authors.initials: S
authors.lastname: Daxböck-Horvath
authors.forename: Holger
authors.initials: H
authors.lastname: Bohlmann
authors.forename: Aart J E
authors.initials: AJ
authors.lastname: van Bel
authors.forename: Florian M W
authors.initials: FM
authors.lastname: Grundler
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D015726:Giant Cells / Q000378:metabolism* / Q000469:parasitology; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009348:Nematoda / Q000502:physiology*; D010935:Plant Diseases / Q000469:parasitology*; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism / Q000469:parasitology
chemical_list: D029681:Arabidopsis Proteins; D009004:Monosaccharide Transport Proteins