Cloning And Expression Analysis Of SAMS Gene From Zea Mays

S-adenosyl-L-metnionine synthetase(SAMS),which is a key enzyme in the metabolize of the plant,is a ubiquitous enzyme catalyzing the synthesis of S-adenosyl-L-ethionine from ATP and L-methionine,S-adenosyl-L-methionine is an important substance in metabolism pathway.And takes part in more than forty kind of biochemical reactions,such as the gene expression,cell membrane fluidity and the synthesis of peptide In plant SAM is invoved in the ethylene,polyamines synthesis,lipid reaction and betaine metabolism.Shen 131 inbred lines of maize for materials,Trizol methods and heat phenol law adopted from clover leaves of maize seedlings from the total RNA,The cDNA was obtained by using the reverse-transcriptase.According to Oryza sativa,Triticum aestivum of the SAMS cDNA sequences,BLAST to get through the highest homology with the maize sequence.We successfully synthesized the sequence of SAMS gene of maize with RT-PCR technology.The sequencing data showed 1191 bp,encoding 496 predicted amino acid residues.The sequence of SAMS gene in 94%,90%,87%,87%when compared with Oryza sativa,Oryza rufipogon partial,Triticum aestivum,Hordeum-vulqure.By meas of Bioinformatics metheds,homology analysis revealed that the hydrophobicity of this SAMS protein was predicted to Hydrophilic,and no transmembrane regions.The secondary structure was primarily composed of random coiland and alpha helix.A three-dimensionnal model was built using homology modeling method.Using maize database analase have four high sequence similarity(ZmEvi076578, ZmEvi040273,ZmEvi066182,ZmEvi050674),the similarity was 100%,98%,71%,48%.ZmEvi050674 and ZmEvi076578 at 8 in the chromosomes,ZmEvi040273 and ZmEvi 066182 at 10 and 3 in the chromosome.The amino acid sequence are not included intron.Conserved domain analysis made it clear that four genes have ATP binding sites,methionine binding sites,the active site controlling the catalytic efficiency,only ZmEvi050674 has no phosphate-binding region.The phylogenetic tree which constructioned from twenty specied and SAMS gene family of Oryza sativa,Zea mays,Arabidopsis thaliana.These species for the two-cluster and Gramineous,cruciferous,leguminous for one cluster.In the first cluster of Zea mays have four types,ZmEvi066182 and ZmEvi050674 amino acid similarity was 29.1%,ZmEvi 050674 and ZmEvi040273 the similarity was 51.1%,Arabidopsis thaliana have two types.Northern-boltting results showed that the gene was constitutive expression,and there has different expression under different forms.The expression level of SAMS gene increase when salt stress,But at the same time infliction folic acid,choline chloride, betain.The expression level reduce in choline chloride and betain.The expression level no more change in folio acid.Cloning and expression analysis of SAMS genes for study the gene family members in the expression of Zea mays and metabolic pathway laid the foundation.