Beschreibung:
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 efficientAgrobacterium tumefaciens-mediated transformation system has been established that is applied for translational research. In the current transformation vectors, the promoters of the35Sgene 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 inBrachypodium distachyon, a model grass distantly related to maize. After the correspondingBrachypodiumpromoters 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 promoterspBdEF1αandpBdUBI10were constitutively and highly active in maize, whereaspBdGLU1was clearly endosperm-specific, hence, expanding the toolbox for transgene analysis in maize. The data indicate thatBrachypodiumis an excellent resource for promoters for transgenic research in heterologous cereal species.