title: Brachypodium distachyon promoters as efficient building blocks for transgenic research in maize.
abstract: The biotechnological approach to improve performance or yield of crops or for engineering metabolic pathways requires the expression of a number of transgenes, each with a specific promoter to avoid induction of silencing mechanisms. In maize (Zea mays), used as a model for cereals, an efficient Agrobacterium tumefaciens-mediated transformation system has been established that is applied for translational research. In the current transformation vectors, the promoters of the 35S gene of the cauliflower mosaic virus and of the ubiquitin gene of maize are often used to drive the bialaphos-selectable marker and the transgene, respectively. To expand the number of promoters, genes with either constitutive or seed-specific expression were selected in Brachypodium distachyon, a model grass distantly related to maize. After the corresponding Brachypodium promoters had been fused to the β-glucuronidase reporter gene, their activity was followed throughout maize development and quantified in a fluorimetric assay with the 4-methylumbelliferyl β-D-glucuronide substrate. The promoters pBdEF1α and pBdUBI10 were constitutively and highly active in maize, whereas pBdGLU1 was clearly endosperm-specific, hence, expanding the toolbox for transgene analysis in maize. The data indicate that Brachypodium is an excellent resource for promoters for transgenic research in heterologous cereal species.
authors.affiliation: Department of Plant Systems Biology, VIB, 9052 Gent, Belgium.
authors.forename: Griet
authors.initials: G
authors.lastname: Coussens
authors.forename: Stijn
authors.initials: S
authors.lastname: Aesaert
authors.forename: Wim
authors.initials: W
authors.lastname: Verelst
authors.forename: Marlies
authors.initials: M
authors.lastname: Demeulenaere
authors.forename: Sylvie
authors.initials: S
authors.lastname: De Buck
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Njuguna
authors.forename: Dirk
authors.initials: D
authors.lastname: Inzé
authors.forename: Mieke
authors.initials: M
authors.lastname: Van Lijsebettens
mesh_terms: D058431:Brachypodium / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D025801:Ubiquitin / Q000235:genetics* / Q000378:metabolism; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D025801:Ubiquitin; D005966:Glucuronidase