Mechanism Of DNA Methylation Of MDD Gene Promoter On Saponin Synthesis In Eleutherococcus Senticosus

Mevalonate pyrophosphate decarboxylase(MDD)is a key enzyme in the terpenoid biosynthesis pathway of Eleutherococcus senticosus,which plays an important role in the upstream regulation of secondary plant metabolism.The promoter region of MDD gene was methylated by bisulfite sequencing,and then the transcriptome sequencing of E.senticosus with different DNA methylation types in the promoter of MDD gene was carried out to clarify the effect of DNA methylation on gene expression and saponin synthesis.At the same time,the gene family and adaptive evolution of Campanulids MDD including E.senticosus were analyzed.The results showed that there were 2 Cp G islands and 28 methylation sites in the MDD promoter of E.senticosus.The methylation rates of the Type A,Type B and Type C were 0.68%,0.72% and 0.79%.The results of transcriptome sequencing showed that the expression of MDD gene of E.senticosus was significantly up-regulated in methylation Type A(P<0.05).There was a significant negative correlation between the saponin content of E.senticosus and the DNA methylation ratio of its MDD promoter(P<0.05).The screening results of differentially expressed transcription factors among 3 DNA methylation proportion samples showed that a total of 4 transcription factors ERF,LBD,C2H2 and GRAS could bind to 4 Cp G sites with DNA methylation status in the MDD promoter of E.senticosus.Protein interaction analysis showed that MDD of E.senticosus could interact with other key enzymes in terpenoid biosynthesis pathway.It was also found that the DNA methylation of E.senticosus MDD promoter was mainly regulated by DNA methyltransferase.After purification and selection,the MDD gene of Campanulids showed a high degree of conservation.In addition,MDD was significantly affected by cold and methyl jasmonate.The results provide a theoretical and technical basis for clarifying the synthesis mechanism of E.senticosus saponins regulated by MDD gene and the regulation mechanism of functional genes on secondary metabolism in other medicinal plants.Figure 38;Table 20;Reference 110...