Isolation and Sequence Analysis of Low Molecular Weight Glutenin Subunit from Leymus mollis

Eight sequences of low molecular weight glutenin subunit(LMW-GS)were isolated from the genome of Leymus mollis by AS-PCR.Nucleotide sequence analysis showed that sequence GQ169791 was composed of a promoter 318 bp,and a coding region,length of 894 bp.The promoter sequence from 5’ to 3’ flanking contained multiple cis-or trans-acting regulatory elements on glutenin gene-specific expression,such as-300 element,GCN4 motif,E-box,Prolamin box,and TATA box.Deduced amino acid sequence analysis indicated that the coding region of these eight sequences had typical multi-peptide primary structure of LMW-GS:signal peptide,N-terminal region,central repeat region,and C-terminal Ⅰ,Ⅱ,Ⅲ domains;Sequence HQ416909,HQ416914 and HQ416915 had the single complete opening reading frame(ORF),while sequence GQ169791,HQ416910,HQ416911,HQ416912 and HQ416913 were likely pseudogenes due to the four or five early termination codons in the central repeat region and C-terminal domain.There were eight or nine cysteine residues in these eight amino acid sequences,and the starting amino acid sequence in the N-terminal region was METSRIPG-or METTRIPG-,which demonstrated that they were m-type LMW-GS genes.Phylogenetic analysis indicated that these eight sequences may have a comparatively close homologous relationship with the LMW-GS genes(HM475146,GQ223386)from Psathyrostachys huashanica and the B-hordein gene(AY695368)from Hordeum brevisubulatum.This research provides a theoretical basis for excavating and utilizing the LMW-GS gene of Leymus mollis,and offers some reference value to wheat quality improvement.