title: Simultaneous boosting of source and sink capacities doubles tuber starch yield of potato plants.
abstract: An important goal in biotechnological research is to improve the yield of crop plants. Here, we genetically modified simultaneously source and sink capacities in potato (Solanum tuberosum cv. Desirée) plants to improve starch yield. Source capacity was increased by mesophyll-specific overexpression of a pyrophosphatase or, alternatively, by antisense expression of the ADP-glucose pyrophosphorylase in leaves. Both approaches make use of re-routing photoassimilates to sink organs at the expense of leaf starch accumulation. Simultaneous increase in sink capacity was accomplished by overexpression of two plastidic metabolite translocators, that is, a glucose 6-phosphate/phosphate translocator and an adenylate translocator in tubers. Employing such a 'pull' approach, we have previously shown that potato starch content and yield can be increased when sink strength is elevated. In the current biotechnological approach, we successfully enhanced source and sink capacities by a combination of 'pull' and 'push' approaches using two different attempts. A doubling in tuber starch yield was achieved. This successful approach might be transferable to other crop plants in the future.
authors.affiliation: Cologne Biocenter, Botanical Institute II, University of Cologne, Cologne, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Jonik
authors.forename: Uwe
authors.initials: U
authors.lastname: Sonnewald
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Hajirezaei
authors.forename: Ulf-Ingo
authors.initials: UI
authors.lastname: Flügge
authors.forename: Frank
authors.initials: F
authors.lastname: Ludewig
mesh_terms: D018556:Crops, Agricultural / Q000201:enzymology / Q000235:genetics; D051599:Glucose-1-Phosphate Adenylyltransferase / Q000378:metabolism*; D018515:Plant Leaves / Q000201:enzymology; D035281:Plant Tubers / Q000737:chemistry*; D011755:Pyrophosphatases / Q000378:metabolism*; D011198:Solanum tuberosum / Q000201:enzymology* / Q000235:genetics; D013213:Starch / Q000096:biosynthesis*
chemical_list: D013213:Starch; D051599:Glucose-1-Phosphate Adenylyltransferase; D011755:Pyrophosphatases