Product Variability of the ‘Cineole Cassette＇ Monoterpene Synthases of Related Nicotiana Species

• Published in: Molecular plant 2011-11, Vol.4 (6), p.965-984
• Main Authors: Fähnrich, Anke, Krause, Katrin, Piechulla, Birgit
• Format: Article
• Language: English
• Subjects: 1,8-cineole, α-terpineol; Amino Acid Sequence; Catalytic Domain; cineole cassette; Cyclohexanols - metabolism; Enzymes; Eucalyptol; Evolution, Molecular; Flowers & plants; Flowers - enzymology; Flowers - genetics; Flowers - metabolism; Intramolecular Lyases - chemistry; Intramolecular Lyases - genetics; Intramolecular Lyases - isolation & purification; Intramolecular Lyases - metabolism; Models, Molecular; Molecular Sequence Data; monoterpene synthase; Monoterpenes - metabolism; multiproduct enzyme; Nicotiana - classification; Nicotiana - enzymology; Nicotiana - genetics; Nicotiana - metabolism; Nicotiana alata; Nicotiana langsdorfii; Phylogeny; Protein Transport; terpineol synthase; 产品; 单萜; 可变性; 合酶; 桉叶素; 物种; 盒式; 草相
• ISSN: 1674-2052; 1752-9867
• DOI: 10.1093/mp/ssr021

Nicotiana species of the section Alatae characteristically emit the floral scent compounds of the ＇cineole cassette＇ comprising 1,8-cineole, limonene, myrcene, α-pinene, β-pinene, sabinene, and α-terpineol. We successfully isolated genes of Nicotiana alata and Nicotiana langsdorfii that encoded enzymes, which produced the characteristic monoter- penes of this ＇cineole cassette＇ with α-terpineol being most abundant in the volatile spectra. The amino acid sequences of both terpineol synthases were 99% identical. The enzymes cluster in a monophyletic branch together with the closely related cineole synthase of Nicotiana suaveolens and monoterpene synthase 1 of Solanum lycopersicum. The cyclization reactions （α-terpineol to 1,8-cineole） of the terpineol synthases of N. alata and N. langsdorfii were less efficient compared to the ＇cineole cassette＇ monoterpene synthases of Arabidopsis thaliana, N. suaveolens, Salvia fruticosa, Salvia officinalis, and Citrus unshiu. The terpineol synthases of IV. alata and N. langsdorfii were localized in pistils and in the adaxial and abaxial epidermis of the petals. The enzyme activities reached their maxima at the second day after anthesis when flowers were fully opened and the enzyme activity in N. alata was highest at the transition from day to night （diurnal rhythm）.