title: Expression of the nos operon proteins from Pseudomonas stutzeri in transgenic plants to assemble nitrous oxide reductase.
abstract: Nitrous oxide (N(2)O) is a stable greenhouse gas that plays a significant role in the destruction of the ozone layer. Soils are a significant source of atmospheric N(2)O. It is important to explore some innovative and effective biology-based strategies for N(2)O mitigation. The enzyme nitrous oxide reductase (N(2)OR), naturally found in soil bacteria, is responsible for catalysing the final step of the denitrification pathway, conversion of N(2)O to dintrogen gas (N(2)). To transfer this catalytic pathway from soil into plants and amplify the abundance of this essential mechanism (to reduce global warming), a mega-cassette of five coding sequences was assembled to produce transgenic plants heterologously expressing the bacterial nos operon in plant leaves. Both the single-gene transformants (nosZ) and the multi-gene transformants (nosFLZDY) produced active recombinant N(2)OR. Enzymatic activity was detected using the methyl viologen-linked enzyme assay, showing that extracts from both types of transgenic plants exhibited N(2)O-reducing activity. Remarkably, the single-gene strategy produced higher reductase capability than the whole-operon approach. The data indicate that bacterial N(2)OR expressed in plants could convert N(2)O into inert N(2) without involvement of other Nos proteins. Silencing by homologous signal sequences, or cryptic intracellular targeting are possible explanations for the low activities obtained. Expressing N(2)OR from Pseudomonas stutzeri in single-gene transgenic plants indicated that such ag-biotech solutions to climate change have the potential to be easily incorporated into existing genetically modified organism seed germplasm.
authors.affiliation: Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, Centre for Research on Environmental Microbiology, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada.
authors.forename: Shen
authors.initials: S
authors.lastname: Wan
authors.forename: Yaseen
authors.initials: Y
authors.lastname: Mottiar
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Johnson
authors.forename: Kagami
authors.initials: K
authors.lastname: Goto
authors.forename: Illimar
authors.initials: I
authors.lastname: Altosaar
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D057075:Enzyme Assays; D005798:Genes, Bacterial; D005822:Genetic Vectors / Q000235:genetics; D009584:Nitrogen / Q000378:metabolism; D009609:Nitrous Oxide / Q000378:metabolism; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D021382:Protein Sorting Signals; D044223:Pseudomonas stutzeri / Q000201:enzymology / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D011994:Recombinant Proteins; D010088:Oxidoreductases; C022763:nitrous oxide reductase; D009609:Nitrous Oxide; D009584:Nitrogen