The Plastidic Sugar Transporter pSuT Influences Flowering and Affects Cold Responses. Issue 2 (27th November 2018)

• Record Type: Journal Article
• Authors: Patzke, Kathrin; Prananingrum, Pratiwi; Klemens, Patrick A.W.; Trentmann, Oliver; Rodrigues, Cristina Martins; Keller, Isabel; Fernie, Alisdair R.; Geigenberger, Peter; Bölter, Bettina; Lehmann, Martin; Schmitz-Esser, Stephan; Pommerrenig, Benjamin; Haferkamp, Ilka; Neuhaus, H. Ekkehard
• Is Part Of: Plant physiology. Volume 179:Issue 2(2019)
• Page Start: 569
• Page End: 587
• Publication Date: 2018-11-27
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.18.01036
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : pSuT, a chloroplast envelope-localized monosaccharide transporter, mediates sucrose transport to the cytosol, which modulates flowering time, stem branching, and cold tolerance in Arabidopsis. Abstract: Sucrose (Suc) is one of the most important types of sugars in plants, serving inter alia as a long-distance transport molecule, a carbon and energy storage compound, an osmotically active solute, and fuel for many anabolic reactions. Suc biosynthesis and degradation pathways are well known; however, the regulation of Suc intracellular distribution is poorly understood. In particular, the cellular function of chloroplast Suc reserves and the transporters involved in accumulating these substantial Suc levels remain uncharacterized. Here, we characterize the plastidic sugar transporter (pSuT) in Arabidopsis ( Arabidopsis thaliana ), which belongs to a subfamily of the monosaccharide transporter-like family. Transport analyses with yeast cells expressing a truncated, vacuole-targeted version of pSuT indicate that both glucose and Suc act as substrates, and nonaqueous fractionation supports a role for pSuT in Suc export from the chloroplast. The latter process is required for a correct transition from vegetative to reproductive growth and influences inflorescence architecture. Moreover, pSuT activity affects freezing-induced electrolyte release. These data further underline the central function of the chloroplast for plant development and the modulation of stress tolerance.