Cloning And Functional Characterization Of MlCCoAOMT1 In Miscanthus. Lutarioriparius

Lignin is a complicated aromatic polymer,its biosynthesis starts from phenylalanine,many enzymes participates in this progress.CCoAOMT is one of the key enzymes in lignin biosynthesis pathway and has been shown to act as a key enzyme to influence the G and S component of lignin monomer.To study MICCoAOMT1 and its function is very helpful for us to unveil the mechanism of lignin biosynthesis and its regulation mechanism,which can provide theoretical basis to the genetic modification of lignocellulosic biomass in M.lutarioriparius.In this study,we cloned MICCoAOMTI gene from M.lutarioriparius.The expression patterns of MICCoAOMT1 studied by quantitative real-time RT-PCR(qRT-PCR),the results showed that MICCoAOMT1 vwas preferentially expressed in sheath and stem.The mRNA in-situ hybridization shows that MICCoAOMT1 was preferentially expressed in sclerenchyma.MICCoAOMT1 was overexpressed in Arabidopsis thaliana wild type(WT)and ccoaomtl mutant by agrobacterium mediated transformation,and MICCoAOMT1 over-expression and restored lines were obtained.Comparative analysis of the four plants has shown that the secondary xylem collapse in ccoaomt,the secondary cell wall was thicken in MICCoAOMT1 over-expressed plants,and collapsed secondary xylem restored in MICCoAOMT1 restored plants;and the lignin content in ccoaomt is much lower than in WT,the lignin content in MICCoAOMT1 over-expressed plants is higher than in WT,while the lignin content in MICCoAOMT1 restored plants is much higher than in ccoaomt,though is not restored to the WT level.These results indicated that the function of MICCoAOMT1 is conserved with Arabidopsis CCoAOMT,and plays an important role in lignin biosynthesis in M.lutarioriparius.