Isolation and functional characterization of a τ-cadinol synthase, a  new sesquiterpene synthase from Lavandula angustifolia.
In this paper we characterize three sTPSs: a germacrene D (LaGERDS), a (E)-β-caryophyllene (LaCARS) and a τ-cadinol synthase (LaCADS). τ-cadinol synthase is reported here for the first time and its activity was studied in several biological models including transiently or stably transformed tobacco species. Three dimensional structure models of LaCADS and Ocimum basilicum γ-cadinene synthase were built by homology modeling using the template structure of Gossypium arboreum δ-cadinene synthase. The depiction of their active site organization provides evidence of the global influence of the enzymes on the formation of τ-cadinol: instead of a unique amino-acid, the electrostatic properties and solvent accessibility of the whole active site in LaCADS may explain the stabilization of the cadinyl cation intermediate. Quantitative PCR performed from leaves and inflorescences showed two patterns of expression. LaGERDS and LaCARS were mainly expressed during early stages of flower development and, at these stages, transcript levels paralleled the accumulation of the corresponding terpene products (germacrene D and (E)-β-caryophyllene). By contrast, the expression level of LaCADS was constant in leaves and flowers. Phylogenetic analysis provided informative results on potential duplication process leading to sTPS diversification in lavender.
Frédéric
F
Jullien
Sandrine
S
Moja
Aurélie
A
Bony
Sylvain
S
Legrand
Cécile
C
Petit
Tarek
T
Benabdelkader
Kévin
K
Poirot
Sébastien
S
Fiorucci
Yann
Y
Guitton
Florence
F
Nicolè
Sylvie
S
Baudino
Jean-Louis
JL
Magnard
D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D027523:Lavandula / Q000201:enzymology* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism*
D010940:Plant Proteins; D018749:RNA, Plant; D012717:Sesquiterpenes; D019883:Alkyl and Aryl Transferases