Cloning,Identification And Catalytic Activity Of SABATHMTs Gene Family From Larix Kaempferi

SABATHMTs is an enzymes that use S-adenosyladenyl-L-methionine(SAM)as a methyl donor to catalyze the methylation of some small molecule metabolites in plants.The methyl group is transferred to the C,0,N,or S atoms of the acceptor molecule to form the corresponding methylated product and S-adenosyl homocysteine..The substrates and products of SABATH methyltransferase play an important part among the processes of higher plants development,participating in plant growth,defense,transmission and pollination.In this study,Japanese larch was used as research material to explore the evolutionary relationship and functional differentiation mechanism of the gymnosperm SABATHMTs gene family members.The molecular evolution,gene expression and protein function analysis of the Larix SABATH gene family were carried out by methods such as sequence identification,phylogenetic analysis,molecular cloning,protein expression purification and protein catalytic activity.Obtained results are as follows:(1)In this study,a total of 42 SABATH genes were identified in the Larix genome,compared with the angiosperms Arabidopsis,Oryza sativa and Populus trichocarpa,and gymnosperm Picea glauca,gene expansionwas observed in the Larix SABATH gene family.(2)The genetic structure of 42 SABATH genes has undergone differentiation.All of 42 genes have the typical SABATH domain Methyltransf?7 by conserved domain prediction.Protein primary structure sequence analysis also found that most proteins have conserved sites that bind to SAM.Gene structure analysis found that some genes between different subfamilies and within the same subfamily have different gene structures.(3)It is speculated that SABATH existed earlier in angiosperms compared to gymnosperms.Phylogenetic analysis of terrestrial plants found that the SABATH gene was divided into 7 subclasses(Clade?-?,Class?-?),and two subclasses contained only angiosperms and were far from the relationship of Larix.(4)The catalytic activitys of a substrate was difference in the same subfamily and between different subfamilies,it shows that there is obvious functional differentiation among the members of the Larix SABATH gene family.After purification of 18 recombinant proteins successfully induced by soluble expression,the activity was found that La SABATH30 showed obvious activity on IAA,9 La SABATH proteins showed activity on Theobromine,all proteins were active on Thiobenzoic acid,and different proteins have different substrate specificities.Based on the data of gene sequence identification,gene structure,phylogeny,tissue expression pattern,protein expression and activity determination data,the molecular evolution and functional differentiation of the members of the Larix SABATH methyltransferase gene family are preliminary explored for further research on gymnosperms The function of the SABATH family provides a reference.