title: Heat-inducible expression of FLP gene in maize cells.
abstract: The soybean heat-shock gene promoter (Gmhsp 17.5-E) has been used to direct expression of gusA and FLP genes in maize cells. At inducible temperatures, in transient expression assays, gusA gene expression controlled by the heat-shock promoter is about 10-fold higher than the expression directed by the CaMV 35S promoter. The Gmhsp 17.5-E promoter preserves its regulatory functions in heterologous maize cells after random integration into genomic DNA. Heat-shock inducible expression of the FLP gene was investigated by co-transformation of the FLP expression vector (pHsFLP) and a recombination test vector (pUFNeoFmG) into maize protoplasts. Co-transformed protoplasts were incubated at 42 degrees C for 2 h. This treatment induced recombination of 20-25% of the available FRT sites in transient assays. As a result of heat-shock treatment of stably co-transformed maize cells, activation of gusA gene expression and an associated decrease or elimination of NPT-II activity in transgenic maize lines was observed. Molecular evidence was obtained of the expected DNA excision process catalyzed by the FLP protein in maize transgenic cells. Thus, the experiments presented in this paper indicate that the FLP protein can recognize and subsequently recombine the FRT target sites that had integrated into plant genomic DNA, and that regulated expression of the FLP gene is possible in maize cells using the soybean heat-shock promoter.
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Lyznik
authors.forename: L
authors.initials: L
authors.lastname: Hirayama
authors.forename: K V
authors.initials: KV
authors.lastname: Rao
authors.forename: A
authors.initials: A
authors.lastname: Abad
authors.forename: T K
authors.initials: TK
authors.lastname: Hodges
mesh_terms: D001483:Base Sequence; D004254:DNA Nucleotidyltransferases / Q000096:biosynthesis* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005822:Genetic Vectors; D005966:Glucuronidase / Q000235:genetics; D006360:Heat-Shock Proteins / Q000235:genetics; D006358:Hot Temperature; D008969:Molecular Sequence Data; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis; D011995:Recombination, Genetic; D013025:Glycine max / Q000235:genetics; D014170:Transformation, Genetic; D003313:Zea mays / Q000235:genetics
chemical_list: D006360:Heat-Shock Proteins; D011994:Recombinant Proteins; D004254:DNA Nucleotidyltransferases; C045119:FLP recombinase; D005966:Glucuronidase