关键词: 阔叶薰衣草, 芳樟醇合成酶, 基因克隆, 序列分析, 植物表达载体构建

Abstract: In this study, a full length cDNA encoding linalool synthase was successfully cloned from the fresh leaves of Lavandula latifolia, with newly gene-specific primers by reverse transcription (RT)-PCR technology. The sequence was 1 809 bp and contained a complete open reading frame (ORF) of 1 809 bp encoding 602 amino acids, and the protein sequences exhibited the highest similarity (98%) with L.latifolia linalool synthase announced on NCBI, with the differences of 21 nucleotide and 11 amino acid, respectively. The gene was named as Lslis. The sequence analysis showed that: Lslis presented three typical conserved motifs of many terpene synthases. There was a peptide sequence DDXXD which is essential for the enzymatic activity of linalool synthase. The molecular weight and isoeletric point of Lslis were predicted to be 70.36 kD and 5.66, respectively. Most of the amino acid sequences of Lslis were hydrophilic regions, which was hydrophilic polypeptide. The results of predicted secondary structure for Lllis and Lslis showed that both the most structures kept consistent, but Lslis had less a α helix to Lllis, which has been promulgated on NCBI. The PCR product was cloned into pMD18-T vector. The Lslis gene expression vector was constructed successfully, having the aid of intermediate plant expression vector pCAMBIA1303. Reconbinant expression vector was identified by PCR analysis, PCR indicated plant vector was transferred into A.tumefaciens.

Key words: Lavandula latifolia, linalool synthase, gene cloning, sequence analysis, construction of plant expression vector