title: Stable co-transformation of maize protoplasts with gusA and neo genes.
abstract: An efficient co-transformation protocol using polyethylene glycol was developed for Zea mays L. (cv. A188 x BMS) protoplasts isolated from suspension culture cells. Co-transformation was accomplished by using plasmid constructions containing beta-glucuronidase (gusA) or neomycin phosphotransferase (neo) gene coding sequences; both were under control of the CaMV 35S promoter. Protoplast culture and transformation conditions were optimized to assure efficient recovery of transformed cells. The overall efficiency of transformation was 1 x 10(-4) (calculated per viable protoplast plated). Among kanamycin-resistant lines, 50% showed a high level of GUS activity (above one unit). Southern blot hybridization confirmed the presence of numerous gusA and neo coding sequences in the maize genome. In two analyzed lines, integrated sequences appeared to be organized in tandem head-to-tail repeats. Results also indicated that the integrated sequences were partially methylated.
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907.
authors.forename: L A
authors.initials: LA
authors.lastname: Lyznik
authors.forename: R D
authors.initials: RD
authors.lastname: Ryan
authors.forename: S W
authors.initials: SW
authors.lastname: Ritchie
authors.forename: T K
authors.initials: TK
authors.lastname: Hodges
mesh_terms: D004247:DNA / Q000235:genetics; D005818:Genetic Engineering; D005822:Genetic Vectors; D005966:Glucuronidase / Q000235:genetics; D019868:Kanamycin Kinase; D007613:Kanamycin Resistance / Q000235:genetics; D010770:Phosphotransferases / Q000235:genetics; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics*; D010957:Plasmids; D011092:Polyethylene Glycols; D011523:Protoplasts; D014170:Transformation, Genetic; D003313:Zea mays / Q000201:enzymology / Q000235:genetics
chemical_list: D011092:Polyethylene Glycols; D004247:DNA; D010770:Phosphotransferases; D019868:Kanamycin Kinase; D005966:Glucuronidase