title: Enhancing soybean photosynthetic CO2assimilation using a cyanobacterial membrane protein, ictB.
abstract: Soybean C3photosynthesis can suffer a severe loss in efficiency due to photorespiration and the lack of a carbon concentrating mechanism (CCM) such as those present in other plant species or cyanobacteria. Transgenic soybean (Glycine max cv. Thorne) plants constitutively expressing cyanobacterial ictB (inorganic carbon transporter B) gene were generated using Agrobacterium-mediated transformation. Although more recent data suggest that ictB does not actively transport HCO3-/CO2, there is nevertheless mounting evidence that transformation with this gene can increase higher plant photosynthesis. The hypothesis that expression of the ictB gene would improve photosynthesis, biomass production and seed yield in soybean was tested, in two independent replicated greenhouse and field trials. Results showed significant increases in photosynthetic CO2uptake (Anet) and dry mass in transgenic relative to wild type (WT) control plants in both the greenhouse and field trials. Transgenic plants also showed increased photosynthetic rates and biomass production during a drought mimic study. The findings presented herein demonstrate that ictB, as a single-gene, contributes to enhancement in various yield parameters in a major commodity crop and point to the significant role that biotechnological approaches to increasing photosynthetic efficiency can play in helping to meet increased global demands for food.
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana-Champaign, IL, 61801-3838, USA; Plant Polymer Research Unit, USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, 1815 N, University Street, Peoria, IL, 61604, USA.
authors.forename: William T
authors.initials: WT
authors.lastname: Hay
authors.affiliation: School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, 68583-0968, USA.
authors.forename: Saadia
authors.initials: S
authors.lastname: Bihmidine
authors.affiliation: Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588-0664, USA.
authors.forename: Nedim
authors.initials: N
authors.lastname: Mutlu
authors.affiliation: Department of Agronomy & Horticulture, Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588-0660, USA.
authors.forename: Khang Le
authors.initials: KL
authors.lastname: Hoang
authors.affiliation: School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, 68583-0968, USA.
authors.forename: Tala
authors.initials: T
authors.lastname: Awada
authors.affiliation: Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588-0664, USA.
authors.forename: Donald P
authors.initials: DP
authors.lastname: Weeks
authors.affiliation: Department of Agronomy & Horticulture, Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588-0660, USA. Electronic address: tclemente1@unl.edu.
authors.forename: Tom E
authors.initials: TE
authors.lastname: Clemente
authors.affiliation: Department of Plant Biology, University of Illinois, Urbana-Champaign, IL, 61801-3838, USA; Lancaster Environment Centre, University of Lancaster, Lancaster, LA1 4YQ, UK. Electronic address: Slong@illinois.edu.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Long
mesh_terms: D016960:Agrobacterium tumefaciens / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D018533:Biomass; D002245:Carbon Dioxide / Q000378:metabolism*; D000069599:Crop Production; D000458:Cyanobacteria / Q000235:genetics* / Q000378:metabolism; D018744:DNA, Plant; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*; D010788:Photosynthesis / Q000187:drug effects*; D018515:Plant Leaves / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012639:Seeds / Q000254:growth & development; D013025:Glycine max / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D014170:Transformation, Genetic
chemical_list: D001426:Bacterial Proteins; D018744:DNA, Plant; D008565:Membrane Proteins; D002245:Carbon Dioxide
keywords: Crop yield improvement; Cyanobacteria; Elevated carbon dioxide; Food security; Photosynthesis; Transgenic soybean