Biosynthesis of the Diterpene cis-Abienol in Cell-Free Extracts of Tobacco Trichomes

A Copal-8-ol Diphosphate Synthase from the Angiosperm Cistus creticus subsp. creticus Is a Putative Key Enzyme for the Formation of Pharmacologically Active, Oxygen-Containing Labdane-Type Diterpenes

“…Although Guo et al (1994) and Guo and Wagner (1995) have hypothesized that copal-8-ol diphosphate is an intermediate in this pathway, no enzyme capable of synthesizing this compound has been reported. Here, we report the characterization of a cDNA of the gene CcCLS, which is expressed in the labdane-producing trichomes of C. creticus subsp.…”

“…The trichomes of Nicotiana glutinosa and Nicotiana tabacum contain the diterpenes abienol, labdenediol, and sclareol, and protein extracts from these species supplied with GGDP were able to support their synthesis (Guo et al, 1994;Guo and Wagner, 1995). It was hypothesized that their synthesis involved a copal-8-ol diphosphate intermediate, but whether one or more enzymes were involved, and indeed the identity of the responsible enzymes, were not determined.…”

Bifunctional cis-Abienol Synthase from Abies balsamea Discovered by Transcriptome Sequencing and Its Implications for Diterpenoid Fragrance Production

“…In addition to balsam fir, a gymnosperm tree, only a few angiosperm plant sources, such as tobacco (Nicotiana tabacum; family Solanaceae) trichomes (8,9) or the tuberous roots of Bolivian sunroot (Polymnia sonchifolia; family Asteraceae) (10) are known to produce cis-abienol 4 in amounts that are relevant for industrial scale extraction. The importance of cisabienol 4 as a plant-derived precursor for the fragrance and bioproducts industry has spawned an interest in the discovery of the relevant biosynthetic genes and enzymes and their future application in metabolically engineered microbial or plant production systems.…”

Trichome Specific Expression: Promoters and Their Applications

“…In the appropriate conditions, the amount of CBT-diols produced by a N. sylvestris leaf may represent up to 10% of the leaf dry weight. Early studies performed on tobacco glandular trichomes concluded that the biosynthesis of the diterpenes takes place in the trichome heads themselves (Keene and Wagner, 1985;Kandra and Wagner, 1988;Guo et al, 1994). This, together with the high productivity of tobacco trichomes makes them an ideal target for terpenoid metabolic engineering.…”

“…Z-abienol is a labdane diterpenoid whose biosynthesis was predicted to require two successive enzymatic steps (Guo et al, 1994), first a copalyl-diphosphate synthase like then a kaurene synthase like enzyme (Peters, 2010). Two candidate genes were thus identified and expressed in N. sylvestris, which does not produce Z-abienol.…”