Cloning of trehalose-6-phosphate synthase gene MeTPS6 from cassava and its expression under abiotic stress

ObjectiveTrehalose-6-phosphate synthase gene MeTPS6 from cassava was cloned,and its expression un-der abiotic stresses including drought,cold and shade was analyzed,in order to provide a reference for the study of TPS gene function and its anti-adversity molecular mechanism.MethodRT-PCR method was applied to clone gene MeTPS6 from cassava leaves,bioinformatics analysis was carried out and a phylogenetic tree was constructed. Fluorescence quanti-tative PCR(qPCR)was used to analyze the expression characteristics and patterns of gene MeTPS6 in different cassava va-rieties and tissues under different abiotic stresses including drought,cold and shade.ResultCloned gene MeTPS6 had a 2565-bp open reading frame,encoded 854 amino acids,and contained a conserved TPS family domain(Glyco_transf_20). Protein MeTPS6 had close genetic relationship with Populus trichocarpa and Salix purpurea,its homologous sequence similarity with P. trichocarpa(Potri. 010G104500)and S. purpurea(SapurV1A. 0015s0610)was up to 92.6%and 90.0%respectively. Promoter sequence in gene MeTPS6 had a large number of abiotic stress related motifs(cold-related motif LTR and drought-related motif MBS),hormone related motifs(abscisic acid related motif ABRE and CE3,salicylic acid related motif TCA-element),and light response related motifs(ACE and Box I). Gene MeTPS6 expressed the highest in storage root,followed by fibrous root,and the expression in these two tissues were significantly higher than those in stem, petiole and leaf(P<0.05,the same below). The expression patterns of gene MeTPS6 were obviously different in various tissues under drought,cold and shade stresses,but its expression was significantly induced under these stresses.ResultAt a high confidence level(Confidence=0.8),thirteen co-expressed genes were found,among which ten were TPS homo-logous genes,suggesting these genes might coordinate with each other and participate in the process of plant biology, while the other three genes(CAT,CAT1,and F5M15.5)encoded catalase and mainly involved in the protection of cells from toxic effects of hydrogen peroxide.ConclusionGene MeTPS6 mainly expresses in cassava root(especially storage root)and participate in the transcriptional regulation of response to drought,cold,and shade stress treatments. It can be served as a candidate to further studying its functions in cassava anti-adversity.