title: A sucrose transporter-interacting protein disulphide isomerase affects redox homeostasis and links sucrose partitioning with abiotic stress tolerance.
abstract: Sucrose accumulation in leaves in response to various abiotic stresses suggests a specific role of this disaccharide for stress tolerance and adaptation. The high-affinity transporter StSUT1 undergoes substrate-induced endocytosis presenting the question as to whether altered sucrose accumulation in leaves in response to stresses is also related to enhanced endocytosis or altered activity of the sucrose transporter. StSUT1 is known to interact with several stress-inducible proteins; here we investigated whether one of the interacting candidates, StPDI1, affects its subcellular localization in response to stress: StPDI1 expression is induced by ER-stress and salt. Both proteins, StSUT1 and StPDI1, were found in the detergent resistant membrane (DRM) fraction, and this might affect internalization. Knockdown of StPDI1 expression severely affects abiotic stress tolerance of transgenic potato plants. Analysis of these plants does not reveal modified subcellular localization or endocytosis of StSUT1, but rather a disturbed redox homeostasis, reduced detoxification of reactive oxygen species and effects on primary metabolism. Parallel observations with other StSUT1-interacting proteins are discussed. The redox status in leaves seems to be linked to the sugar status in response to various stress stimuli and to play a role in stress tolerance.
authors.affiliation: Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany.
authors.forename: Erik
authors.initials: E
authors.lastname: Eggert
authors.affiliation: MPI Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Obata
authors.affiliation: Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Gerstenberger
authors.affiliation: Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany.
authors.forename: Konstanze
authors.initials: K
authors.lastname: Gier
authors.affiliation: Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Brandt
authors.affiliation: MPI Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.affiliation: MPI Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.|University Hohenheim, Department of Plant Systems Biology, 70593, Stuttgart, Germany.
authors.forename: Waltraud
authors.initials: W
authors.lastname: Schulze
authors.affiliation: Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Kühn
mesh_terms: D003001:Cloning, Molecular; D055785:Gene Knockdown Techniques; D006706:Homeostasis / Q000502:physiology; D009004:Monosaccharide Transport Proteins / Q000502:physiology*; D010084:Oxidation-Reduction; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D010940:Plant Proteins / Q000502:physiology*; D030821:Plants, Genetically Modified; D019704:Protein Disulfide-Isomerases / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction; D011198:Solanum tuberosum / Q000196:embryology / Q000502:physiology; D013312:Stress, Physiological / Q000502:physiology; D013395:Sucrose / Q000378:metabolism*
chemical_list: D009004:Monosaccharide Transport Proteins; D010940:Plant Proteins; D013395:Sucrose; D019704:Protein Disulfide-Isomerases
keywords: ROS detoxification; abiotic stress; membrane microdomains; redox metabolites; sucrose transport