Cloning and Analysis of <i>MoTPS</i> and its Promoter in <i>Morinda officinalis</i> How

Abstract

To reveal the sequence characteristics of MoTPS gene of Morinda officinalis and its expression pattern under auxin (IAA) treatment. The coding sequence of three MoTPS genes were obtained by RT-PCR, they were named separately MoTPS1 , MoTPS2 and MoTPS3 . Gene sequence analysis showed that the full-length sequence of three MoTPS genes were separately 2 841 bp, 2 126 bp and 2 144 bp, and contained separately 2 481 bp, 1 668 bp and 1 943 bp open reading frame (ORF), encoding separately 826, 555 and 640 amino acids. The sequence analysis results showed that proteins encoded by three MoTPS genes were hydrophilic unstable protein and amino acid sequences of three genes contained terpenoid specific aspartic acid (DDxxD) enrichment motif, RxR conservative motif, and terpenoid class I superfamily domain. Homology analysis showed that amino acid sequences of three MoTPS genes were similar to TPS gene matched in Coffea Arabica , and these plants belonged to Rubiaceae. Phylogenetic tree analysis showed that MoTPS1 belongs to TPS-f subfamily, but MoTPS2 and MoTPS3 belong to TPS-d subfamily. Among the three MoTPS genes, MoTPS3 gene was screened for promoter isolation ， the length of 5 'end promoter sequence was 739 bp, including a variety of regulatory elements related to light response, stress response and hormone response, such as G-box, Sp1, P-box, TGA-element etc. Fluorescence quantitative PCR analysis showed that the expression of three MoTPS genes were stable and tissue-specific in roots, shoots and leaves. the relative expression levels of three MoTPS genes were significantly up-regulated after IAA treatment. Therefore, this study has speculated that three MoTPS genes are involved in the synthesis of terpenoid secondary metabolites in root of Morinda officinalis and auxin IAA was predicted to play important role in the regulation of MoTPS gene expression.