The Sink-Specific Plastidic Phosphate Transporter PHT4;2 Influences Starch Accumulation and Leaf Size in Arabidopsis

• DOI: 10.1104/pp.111.181925
• Publication Date: 2011-09-30T11:33:16Z
• Authors: Sonia Irigoyen; Patrik M. Karlsson; Jacob Kuruvilla; Cornelia Spetea; Wayne K. Versaw
• Keywords: 0303 health sciences; Base Sequence; Arabidopsis Proteins; Molecular Sequence Data; Arabidopsis; Biological Transport; Flowers; Sequence Analysis, DNA; 15. Life on land; Plant Roots; Carbon; Phosphates; Plant Leaves; Mutagenesis, Insertional; 03 medical and health sciences; Seedlings; Animals; Phosphate Transport Proteins; Plastids; Rabbits; Photosynthesis; Promoter Regions, Genetic; Cell Proliferation

Abstract Nonphotosynthetic plastids are important sites for the biosynthesis of starch, fatty acids, and amino acids. The uptake subsequent use cytosolic ATP to fuel these other anabolic processes would lead accumulation inorganic phosphate (Pi) if not balanced by a Pi export activity. However, identity transporter(s) responsible is unclear. plastid-localized transporter PHT4;2 Arabidopsis (Arabidopsis thaliana) expressed in multiple sink organs but nearly restricted roots during vegetative growth. We identified used pht4;2 null mutants confirm that contributes transport isolated root plastids. Starch was limited roots, which consistent with inhibition starch synthesis excess as result defect export. Reduced leaves altered expression patterns genes plastid suggest metabolic adaptation roots. Moreover, rosettes, were significantly larger than those wild type, 40% greater leaf area twice biomass when plants grown short (8-h) photoperiod. Increased cell proliferation accounted size biomass, no changes detected mature size, specific area, or relative photosynthetic electron These data novel signaling between regulation size.