title: Transplastomic tobacco plants expressing a fatty acid desaturase gene exhibit altered fatty acid profiles and improved cold tolerance.
abstract: The possibility of altering the unsaturation level of fatty acids in plant lipids by genetic transformation has implications for the stress tolerance of higher plants as well as for their nutritional value and industrial utilisation. While the integration and expression of transgenes in the plastome has several potential advantages over nuclear transformation, very few attempts have been made to manipulate fatty acid biosynthesis using plastid transformation. We produced transplastomic tobacco plants that express a Delta(9) desaturase gene from either the wild potato species Solanum commersonii or the cyanobacterium Anacystis nidulans, using PEG-mediated DNA uptake by protoplasts. Incorporation of chloroplast antibiotic-insensitive point mutations in the transforming DNA was used to select transformants. The presence of the transcript and the Delta(9) desaturase protein in transplastomic plants was confirmed by northern and western blot analyses. In comparison with control plants, transplastomic plants showed altered fatty acid profiles and an increase in their unsaturation level both in leaves and seeds. The two transgenes produced comparable results. The results obtained demonstrate the feasibility of using plastid transformation to engineer lipid metabolic pathways in both vegetative and reproductive tissues and suggest an increase of cold tolerance in transplastomic plants showing altered leaf fatty acid profiles. This is the first example of transplastomic plants expressing an agronomically relevant gene produced with the "binding-type" vectors, which do not contain a heterologous marker gene. In fact, the transplastomic plants expressing the S. commersonii gene contain only plant-derived sequences, a clear attraction from a public acceptability perspective.
authors.affiliation: CNR-IGV, Institute of Plant Genetics-Portici, Portici, NA, Italy.
authors.forename: Wendy
authors.initials: W
authors.lastname: Craig
authors.forename: Paolo
authors.initials: P
authors.lastname: Lenzi
authors.forename: Nunzia
authors.initials: N
authors.lastname: Scotti
authors.forename: Monica
authors.initials: M
authors.lastname: De Palma
authors.forename: Paola
authors.initials: P
authors.lastname: Saggese
authors.forename: Virginia
authors.initials: V
authors.lastname: Carbone
authors.forename: Noreen
authors.initials: N
authors.lastname: McGrath Curran
authors.forename: Alan M
authors.initials: AM
authors.lastname: Magee
authors.forename: Peter
authors.initials: P
authors.lastname: Medgyesy
authors.forename: Tony A
authors.initials: TA
authors.lastname: Kavanagh
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Dix
authors.forename: Stefania
authors.initials: S
authors.lastname: Grillo
authors.forename: Teodoro
authors.initials: T
authors.lastname: Cardi
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D001483:Base Sequence; D003080:Cold Temperature; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D044943:Fatty Acid Desaturases / Q000235:genetics*; D005227:Fatty Acids / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019076:Transgenes
chemical_list: D017931:DNA Primers; D005227:Fatty Acids; D044943:Fatty Acid Desaturases