title: Remodeling the isoprenoid pathway in tobacco by expressing the cytoplasmic mevalonate pathway in chloroplasts.
abstract: Metabolic engineering to enhance production of isoprenoid metabolites for industrial and medical purposes is an important goal. The substrate for isoprenoid synthesis in plants is produced by the mevalonate pathway (MEV) in the cytosol and by the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway in plastids. A multi-gene approach was employed to insert the entire cytosolic MEV pathway into the tobacco chloroplast genome. Molecular analysis confirmed the site-specific insertion of seven transgenes and homoplasmy. Functionality was demonstrated by unimpeded growth on fosmidomycin, which specifically inhibits the MEP pathway. Transplastomic plants containing the MEV pathway genes accumulated higher levels of mevalonate, carotenoids, squalene, sterols, and triacyglycerols than control plants. This is the first time an entire eukaryotic pathway with six enzymes has been transplastomically expressed in plants. Thus, we have developed an important tool to redirect metabolic fluxes in the isoprenoid biosynthesis pathway and a viable multigene strategy for engineering metabolism in plants.
authors: Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Albany, CA, USA.
authors: Shashi
authors: S
authors: Kumar
authors: Frederick M
authors: FM
authors: Hahn
authors: Edward
authors: E
authors: Baidoo
authors: Talwinder S
authors: TS
authors: Kahlon
authors: Delilah F
authors: DF
authors: Wood
authors: Colleen M
authors: CM
authors: McMahan
authors: Katrina
authors: K
authors: Cornish
authors: Jay D
authors: JD
authors: Keasling
authors: Henry
authors: H
authors: Daniell
authors: Maureen C
authors: MC
authors: Whalen
mesh_terms: D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism*; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism*; D005578:Fosfomycin / Q000031:analogs & derivatives / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D008798:Mevalonic Acid / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D013729:Terpenes / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D013729:Terpenes; D005578:Fosfomycin; C024640:fosmidomycin; D008798:Mevalonic Acid