关键词: 红花, 1-脱氧-D-木酮糖-5-磷酸合成酶, 基因表达, 原核表达

Abstract: 1-deoxy-D-xylulose-5-phosphate synthase ( DXS) is the first key enzyme of 2-C-Methyl-Derythritol-4-phosphate (MEP) synthetic pathway, which plays an important role in plant terpenoid biosynthesis. In order to clarify the sequence characteristics and expression characteristics of DXS in Carthamus tinctorius L.,a full length cDNA sequence of CtDXS1 gene was cloned by reverse transcription PCR from Carthamus tinctorius L.cultivar‘Yuhonghua No.1’based on the transcriptome data.Meanwhile,bioinformatics analysis and gene expression characteristics analysis were carried out.The open reading frame(ORF) of CtDXS1 gene was 2 136 bp, encoding a protein of 711 amino acids with a calculated molecular mass (MW) of 76 503. 10 u. Protein conserved domain analysis indicated that CtDXS1 contained the conserved domain of transketolase. The phylogenetic analysis indicated that CtDXS1 protein had the highest level of homology with DXS protein from Artemisia annua,and belonged to DXS cladeⅠ.Tissue-specific expression analysis showed that CtDXS1 gene had the highest expression level in bracts,followed by leaves and stems,and lower expression in other tissues.Quantitative analysis of gene expression of different color safflower showed that the expression of CtDXS1 gene was higher in yellow safflower.Drought and low temperature stress induced the CtDXS1 gene expression.The expression of CtDXS1 also induced by MeJA,but GA3 and ABA could inhibite the transcription of CtDXS1.Prokaryotic expression vector pET28a-CtDXS1 was constructed,and transformed into E.coli Transetta(DE3),and CtDXS1 recombinant protein was successfully expressed.

Key words: Carthamus tinctorius L., 1-deoxy-D-xylulose-5-phosphate synthase, Gene expression, Prokaryotic expression