A sucrose transporter‐interacting protein disulphide isomerase affects redox homeostasis and links sucrose partitioning with abiotic stress tolerance. (24th February 2016)

• Record Type: Journal Article
• Authors: Eggert, Erik; Obata, Toshihiro; Gerstenberger, Anne; Gier, Konstanze; Brandt, Tobias; Fernie, Alisdair R.; Schulze, Waltraud; Kühn, Christina
• Is Part Of: Plant, cell and environment. Volume 39:Number 6(2016)
• Page Start: 1366
• Page End: 1380
• Publication Date: 2016-02-24
• Subjects: abiotic stress -- membrane microdomains -- redox metabolites -- ROS detoxification -- sucrose transport; Plant physiology -- Periodicals; Plant cells and tissues -- Periodicals; Plant communities -- Periodicals; 581.105
• DOI: 10.1111/pce.12694
• Languages: English
• ISSNs: 0140-7791

Abstract

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. Abstract : After having identified sucrose transporter interacting proteins we focused on the physiological function of one of the candidates that shows promiscuous interaction with all known sucrose transporters from Solanum tuberosum : a protein disulphide isomerase (PDI) whose main function seems to lie in the maintenance of redox homeostasis under abiotic stresses. Impaired expression of this PDI severely impacts stress tolerance towards drought and salt. Some of these features have already been assigned to another StSUT1‐interacting protein, namely Snakin1, an antimicrobial protein belonging to the GASA protein family.