title: Improved molecular tools for sugar cane biotechnology.
abstract: Sugar cane is a major source of food and fuel worldwide. Biotechnology has the potential to improve economically-important traits in sugar cane as well as diversify sugar cane beyond traditional applications such as sucrose production. High levels of transgene expression are key to the success of improving crops through biotechnology. Here we describe new molecular tools that both expand and improve gene expression capabilities in sugar cane. We have identified promoters that can be used to drive high levels of gene expression in the leaf and stem of transgenic sugar cane. One of these promoters, derived from the Cestrum yellow leaf curling virus, drives levels of constitutive transgene expression that are significantly higher than those achieved by the historical benchmark maize polyubiquitin-1 (Zm-Ubi1) promoter. A second promoter, the maize phosphonenolpyruvate carboxylate promoter, was found to be a strong, leaf-preferred promoter that enables levels of expression comparable to Zm-Ubi1 in this organ. Transgene expression was increased approximately 50-fold by gene modification, which included optimising the codon usage of the coding sequence to better suit sugar cane. We also describe a novel dual transcriptional enhancer that increased gene expression from different promoters, boosting expression from Zm-Ubi1 over eightfold. These molecular tools will be extremely valuable for the improvement of sugar cane through biotechnology.
authors.affiliation: Syngenta Centre for Sugar Cane Biofuels Development, Centre for Tropical Crops and Biocommodities, Queensland University of Technology, Brisbane, QLD, 4001, Australia, Mark.Kinkema@qut.edu.au.
authors.forename: Mark
authors.initials: M
authors.lastname: Kinkema
authors.forename: Jason
authors.initials: J
authors.lastname: Geijskes
authors.forename: Paulo
authors.initials: P
authors.lastname: Delucca
authors.forename: Anthony
authors.initials: A
authors.lastname: Palupe
authors.forename: Kylie
authors.initials: K
authors.lastname: Shand
authors.forename: Heather D
authors.initials: HD
authors.lastname: Coleman
authors.forename: Anthony
authors.initials: A
authors.lastname: Brinin
authors.forename: Brett
authors.initials: B
authors.lastname: Williams
authors.forename: Manuel
authors.initials: M
authors.lastname: Sainz
authors.forename: James L
authors.initials: JL
authors.lastname: Dale
mesh_terms: D000383:Agriculture / Q000379:methods; D001709:Biotechnology / Q000379:methods*; D018506:Gene Expression Regulation, Plant; D006651:Histocytochemistry; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D031786:Saccharum / Q000235:genetics* / Q000378:metabolism; D001617:beta-Glucosidase / Q000235:genetics / Q000378:metabolism
chemical_list: D001617:beta-Glucosidase