title: Multigene manipulation of photosynthetic carbon assimilation increases CO2 fixation and biomass yield in tobacco.
abstract: Over the next 40 years it has been estimated that a 50% increase in the yield of grain crops such as wheat and rice will be required to meet the food and fuel demands of the increasing world population. Transgenic tobacco plants have been generated with altered combinations of sedoheptulose-1,7-bisphosphatase, fructose-1,6-bisphosphate aldolase, and the cyanobacterial putative-inorganic carbon transporter B, ictB, of which have all been identified as targets to improve photosynthesis based on empirical studies. It is shown here that increasing the levels of the three proteins individually significantly increases the rate of photosynthetic carbon assimilation, leaf area, and biomass yield. Furthermore, the daily integrated measurements of photosynthesis showed that mature plants fixed between 12-19% more CO2 than the equivalent wild-type plants. Further enhancement of photosynthesis and yield was observed when sedoheptulose-1,7-bisphosphatase, fructose-1,6-bisphosphate aldolase, and ictB were over-expressed together in the same plant. These results demonstrate the potential for the manipulation of photosynthesis, using multigene-stacking approaches, to increase crop yields.
authors.affiliation: School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester CO4 3SQ, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Simkin
authors.affiliation: School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester CO4 3SQ, UK.
authors.forename: Lorna
authors.initials: L
authors.lastname: McAusland
authors.affiliation: School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester CO4 3SQ, UK.
authors.forename: Lauren R
authors.initials: LR
authors.lastname: Headland
authors.affiliation: School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester CO4 3SQ, UK.
authors.forename: Tracy
authors.initials: T
authors.lastname: Lawson
authors.affiliation: School of Biological Sciences, Wivenhoe Park, University of Essex, Colchester CO4 3SQ, UK rainc@essex.ac.uk.
authors.forename: Christine A
authors.initials: CA
authors.lastname: Raines
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D057486:Carbon Cycle / Q000235:genetics*; D002245:Carbon Dioxide / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics; D005453:Fluorescence; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D017343:Genes, Plant; D008027:Light; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010788:Photosynthesis / Q000235:genetics*; D054046:Plant Stomata / Q000502:physiology; D030821:Plants, Genetically Modified; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism; D036226:Seedlings / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000254:growth & development* / Q000528:radiation effects; D014170:Transformation, Genetic
chemical_list: D002734:Chlorophyll; D002245:Carbon Dioxide; D002244:Carbon; D010744:Phosphoric Monoester Hydrolases; C022627:sedoheptulose-bisphosphatase; D012273:Ribulose-Bisphosphate Carboxylase; D005634:Fructose-Bisphosphate Aldolase
keywords: Biomass; Calvin–Benson cycle; chlorophyll fluorescence imaging; gas exchange; gene stacking.