Cloning and expression analysis of trehalose-6-phosphate synthase gene (CsTPS) from tea plant (Camellia sinensis (L.) O. Kuntz).

Trehalose-6-phosphate Synthase(TPS) is a key enzyme in the synthesis of trehalose in plants. At present, researches about TPS have mainly focused on bacteria and fungi but little about plants. An EST, having high homology with TPS gene from other organisms, was screened from the whole organic transcriptomic library of tea (Camellia sinensis (L.) O. Kuntz) and amplified through RACE technology to obtain the cDNA full-length of trehalose-6-phosphate synthase gene, named CsTPS (GenBank accession number: JQ742017). The cDNA full-length of CsTPS was 3 125 bp with a single 2 799 bp opening reading frame that predicted to encoded a 932 animo acid, which contained two obvious structure domains, TPS and TPP, through multiple sequences alignment. Phylogenetic tree indicated that the deduced animo acid sequence of CsTPS gene had a very high identity with TPS genes from other organisms such as Arabidopsis thaliana, Nicotiana tobacum and Solanum lycopersicum. And the holomogy between CsTPS and AtTPS1 genes was higher than that of AtTPS2 and AtTPS3. Quantitative Real-time PCR analysis showed that differential expression level of CsTPS gene existed in different organs and upregulation of CsTPS gene induced by low temperature in mature leaf and immature leaf were obviously higher than that in roots, which revealed that CsTPS gene may involve in cold-resistant mechanism of tea plant.