凉粉草蔗糖磷酸合酶基因(SPS)的克隆及表达分析OA

Objective:To systematically screen and identify the genes of sucrose phosphosynthase(SPS)involved in polysaccharide biosynthesis in Mesona chinensis,and to conduct gene cloning and gene expression analysis.Methods:The candidate gene was systemati-cally identified from the transcriptome data of Mesona chinensis using BLAST+and hmmsearch,conservative domain analysis and protein function prediction were conducted.The transcripts with high expression levels were amplified in vitro,and gene cloning was carried out by seamless cloning method.The expression of McSPSs gene in the roots,stems and leaves of Mesona chinensis was detected by real-time fluorescence quantitative PCR(qRT-PCR).Results:Eight McSPSs candidate genes were successfully screened from the Mesona chinen-sis transcriptome.All these genes contained conserved domains characteristic of SPS genes,with identical sequences observed for Mc-SPS1～McSPS7.A phylogenetic tree of SPS was constructed,and predictions of protein function and structure were performed.McSPS1 and McSPS8 were successfully amplified from mRNA extracted from the leaves of Mesona chinensis and inserted into the cloning vector pEASY-Blunt,completing the construction of the cloning vector.qRT-PCR analysis revealed that McSPSs genes were expressed in the roots,stems,and leaves of Mesona chinensis,with the highest expression levels observed in the leaves.Among all tissues,McSPS1 exhibi-ted higher expression levels than McSPS8.Conclusion:In this study,eight McSPSs transcripts are identified from Mesona chinensis,and the gene amplification and cloning work is successfully completed.At the same time,the expression of the McSPSs gene in different tis-sues of Mesona chinensis is clarified,laying an experimental foundation for elucidating the molecular mechanism of quality formation of Mesona chinensis.