Isolation Of Genes Encoding MET1from Dendranthema×morifolium And Artemisia Carvifolia And Construction Of RNAi Expression Vector Of Dendranthema×morifolium MET1Gene

Chrysanthemum（Dendranthema×morifolium） is a perennial herbaceous plant with perennial root.Chrysanthemum that has ornamental value consists of wide variety, varied flower color and form.How tochange the related characters to meet the ornamentals and floriculture planting demands has been paid moreattention. Sweet Wormwood Herb(Artemisia carvifolia) is annual herbs and is regarded as the rootstockused in the chrysanthemum grafting. DNA methylation is an research direction of the epigenetics. Regulategene expression by modifying the DNA methylation. The purpose of our research is to knock out the MET1gene in Chrysanthemum through the method of RNA interference which could interfere the MET1gene inChrysanthemum not Southernwood. MET1gene expression pattern of different organizations in these twospecies were analysed through the method of Fluorescence quantitative PCR.Once,we have got thistransgenic rootstock,all the other Chrysanthemum would have a platform which could induced DNAdemethylation.I obtained the homologous fragment of DmMET1and AcMET1by homologous cloning, and obtainedthe residue sequences of MET1through the method of5’RACE and3’RACE. I found that the length ofprotein-coding region of DmMET1gene is5040bp, and another in southernwood is4932bp.Through bioinformatics analysis, the homology between chrysanthemum and southernwood reached92.65%, there were two fragments that the homology was low, and they were from1767base to1867baseand from4021base to4123base in DmMET1gene..One segment from DmMET1gene at the range of1767base has less specifity than AcMET1wasamplified.At last,we construct this fragment into the RNAi vector-DHpart27RNAiFADP1P4.The expression pattern analysis of root, stem, leaf in chrysanthemum and southernwood was carriedout by fluorescence quantitative PCR. The results showed that DmMET1expression values were thehighest in the root, secondly were in the leaf, and the expression values in stem were the lowest. In thesouthernwood, the highest MET1expression values appeared at the stem, secondly appeared at the root,and the expression values in leaf were the lowest.