The Detection And Analysis Of Low Molecular Weight Glutenin Subunit Gene Sequence Coding By Glu-A3 Locus In Wheat Varieties

The 200 Chinese wheat landraces had been screened using 7 allele-specific PCR markers at Glu-A3 locus.The denomination of Glu-A3 alleles of 197 varieties had been identified and,Of these,the number of c,a,d allele is more than other types,and makes up 44.5%,26.0%,14.5%of total varieties,respectively.However,only a small number of varities contain b,e,f,g alleles and the ratio is 4.5%,5.5%,1.0%,2.5%, 1.5%,respectively.In order to know the type of these three unknown varieties,three Xinjiang landraces were sequenced by Glu-A3 locus specific primer using PCR-amplification method(GenBank:DQ519084,DQ519085,and DQ517534).The deduced amino acid sequences comparison suggested that these genes are the LMW-i type genes.The typical features are listed as follows:1.The nucleotide sequence of DQ519084(Hongchunmai),DQ517534 (Hongjinbaoyin),and DQ519085(Hongchunmai)are 1295bp,1294bp and 1293bp long.2.DQ519084 and DQ517534 both contain an open reading frame that starts at nucleotide 172 and 169,encodes the same polypeptide of 369 amino acids. DQ519085 contains a stop code in its coding region,so it is presumed as a pseudogene.3.All the deduced amino acid sequences contain a typical 20 amino acid signal peptide,and N-terminal region starts with ISQQQQ.The three sequences were constituted by 14 repeat polypeptides,such as QQQQ,PPFSQQ,SPFSQQQQQ,PPFLQQQQ,QPFTQQQQ.The deduced sequence of DQ519084 and DQ517534 both contain 9 cysteine residues in C-terminal conserved domain.