Molecular cloning and expression analysis of a putative sesquiterpene synthase gene from tea plant (Camellia sinensis)

A putative gene encoding germacrene D synthase (GenBank Accession No. JQ247185) from tea plant (Camellia sinensis) was isolated by rapid amplification of cDNA ends for the first time, which was designated as tea plant gene terpene synthase 1 (Cstps1). This full-length cDNA was 2,090 nucleotides, and the open reading frame was 1,704 bp encoding polypeptides of 568 amino acids. The deduced amino acid sequence contained two characteristic conserved motifs of RRx(8)W and DDxxD, which showed high homology with sesquiterpene synthases of angiosperms, and the highest level of similarity was 73 % to germacrene D synthase from Actinidia deliciosa (Accession NO. AAX16121.1). Phylogenetic analysis indicated that Cstps1 belonged to the terpene synthase-a subfamily of plant, which was the largest clade of terpene synthases and mainly composed of sesquiterpene synthases. The Cstps1 expression was detected in different organs, with high expression levels in leaf and flower, weak expression in stem and root. Real-time qRT-PCR indicated that Cstps1 could be induced by insect damage, this result suggested Cstps1 might have potential ecological function during tea plant defense response.