Analysis Of Function And Evolution Of PmOMTin Prunus Mume

Prunus mume sieb.et Zucc is a Chinese traditional famous flower, and the O-methyltransferases gene from P.mume has been considered related to the metabolism of eugenol and the formation of methyleugenol. But the molecular mechanism was not clear yet. This study utilizes bioinformatics softwares, for seeking characteristics of sequence of PmOMT gene, which is based on the genome sequencing of P.mume, and exploring the evolutionary relationship between P.mume O-methyltransferase(PmOMTs) gene families and their potential functional divergence, the main results of this research are as follows:1.There are mainly two conserved domains in PmOMT gene, the former regulate the polymerization of proteins, the latter use S-adenosine methionine for methylation reaction, forming S-adenosine-homocysteine (S-adenosyl-L-homocysteine,SAH). There are several highly conservative motives participating in binding with substances in different OMT genes, including VLVGG motif ILPHV motif and GGDMF motif. These sequence characteristics constitute the molecular basis of involvement of PmOMT genes in eugenol metabolism.2. The relative expression of PmOMT gene in the tissue of floral organ is higher than that in nutrition tissues, and mainly concentrated in stamens, petals and pistil. A small amount of expression exist in sepals, leaf, stalk, and root as well, showing the tissue specificity of floral genes in spatial terms.3. It is concluded from phylogenetic analyse of OMTs gene family that OMTs gene families had a wide range of gene duplication before the separation of species. Combing with motif analysis, it is found that the main domain of PmOMT have the trend that evolving from AdoMet MTases to methytransferse2. The functional divergence between these two domains focus on3motives. According to the analysis of function site and selective site, we obtain5functional divergence sites that are important for the formation of methyl eugenol and key region that can be used for site-directed mutagenesis experiments.4. It is found that the synthesis of methyleugenol generation may be concerned with the retroaction of methylation and the regulation of pseudosubstrate. It is analyzed for selective site that the sequence around261site can form the domain binding SAH that hinders the combination of substrate and PmOMT gene, which inhibits gene activity of PmOMT, leading to significant differences between methyl eugenol and eugenol content fragrance ingredient of P.mume. This paper synthetically used the research methods of phylogenetic analysis and comparative genomics, explored the evolution law of the structure of PmOMT, as well as its role in methyleugenol synthesis, and provided insignificant binding sites for directive breeding.