title: Overexpression of a pine Dof transcription factor in hybrid poplars: A comparative study in trees growing under controlled and natural conditions.
abstract: In this work, the role of the pine transcriptional regulator Dof 5 in carbon and nitrogen metabolism has been examined in poplar trees. The overexpression of the gene and potential effects on growth and biomass production were compared between trees growing in a growth chamber under controlled conditions and trees growing in a field trial during two growth seasons. Ten-week-old transgenic poplars exhibited higher growth than untransformed controls and exhibited enhanced capacity for inorganic nitrogen uptake in the form of nitrate. Furthermore, the transgenic trees accumulated significantly more carbohydrates such as glucose, fructose, sucrose and starch. Lignin content increased in the basal part of the stem likely due to the thicker stem of the transformed plants. The enhanced levels of lignin were correlated with higher expression of the PAL1 and GS1.3 genes, which encode key enzymes involved in the phenylalanine deamination required for lignin biosynthesis. However, the results in the field trial experiment diverged from those observed in the chamber system. The lines overexpressing PpDof5 showed attenuated growth during the two growing seasons and no modification of carbon or nitrogen metabolism. These results were not associated with a decrease in the expression of the transgene, but they can be ascribed to the nitrogen available in the field soil compared to that available for growth under controlled conditions. This work highlights the paramount importance of testing transgenic lines in field trials.
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Rueda-López
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
authors.forename: María Belén
authors.initials: MB
authors.lastname: Pascual
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Pallero
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
authors.forename: Luisa María
authors.initials: LM
authors.lastname: Henao
authors.affiliation: Departamento de Ciencias del Medio Natural, Universidad Pública de Navarra, Pamplona, Spain.
authors.forename: Berta
authors.initials: B
authors.lastname: Lasa
authors.affiliation: Departamento de Ciencias del Medio Natural, Universidad Pública de Navarra, Pamplona, Spain.
authors.forename: Ivan
authors.initials: I
authors.lastname: Jauregui
authors.affiliation: Departamento de Ciencias del Medio Natural, Universidad Pública de Navarra, Pamplona, Spain.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Aparicio-Tejo
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Cánovas
authors.affiliation: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain.
authors.forename: Concepción
authors.identifier: http://orcid.org/0000-0001-8817-7529
authors.initials: C
authors.lastname: Ávila
mesh_terms: D018533:Biomass; D050260:Carbohydrate Metabolism / Q000235:genetics; D002244:Carbon / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D018628:Gene Dosage; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006824:Hybridization, Genetic; D018527:Hydroponics; D008031:Lignin / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D028223:Pinus / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D032107:Populus / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014197:Trees / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D002244:Carbon; D002482:Cellulose; D008031:Lignin; D009584:Nitrogen