Characterization of S-(+)-linalool synthase from several provenances of Cinnamomum osmophloeum
2014
Lin, Yan-Liang | Lee, Yi-Ru | Huang, Wen-Ke | Chang, Shang-Tzen | Chu, Fang-Hua
Cinnamomum osmophloeum is a commercially important tree species in Taiwan, which has numerous chemotypes with various secondary metabolite profiles. The linalool chemotype is important because it generates pure S-(+)-linalool with high yield. In the present study, the linalool synthase (LIS) genes were isolated from different provenances of C. osmophloeum. The recombinant proteins of LIS were able to generate the S-(+)-linalool from GPP and (E)-nerolidol from FPP. Kinetic analysis showed differing enzyme activities of similar proteins from different provenances. Two point mutations enhanced enzyme activity up to sixfold. Phylogenetic analysis and leaf volatiles composition analysis clustered the genes into designated groups according to their chemotypes. Because the CoLIS-LL gene has a particularly abundant transcript, we suggest that the W-box, recognized by the WRKY transcription factor, might be responsible for high differential gene expression. A marker based on the W-box sequence can be used to distinguish linalool chemotype.
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