摘要The low molecular weight (LMW) glutenin subunits account for 40% of wheat gluten protein content by mass and these proteins are considered to significantly affect dough quality characteristics. Five new full-length LMW glutenin genes (designated LMW-5, LMW-7, LMW-42, LMW-58, and LMW-34) were isolated from the Chinese elite wheat cultivar "Xiaoyan 54" by PCR amplification of genomic DNA using a pair of degenerate primers designed from the conserved sequences of the N- and C-terminal regions of published LMW glutenln genes.Deduced amino acid sequence analysis showed that LMW-5 belongs to the LMW-itype genes and that the other four belong to LMW-m type genes. Sequence comparisons revealed that point mutations occasionally occurred in signal peptide and N-terminus domains and often existed in domain Ⅲ and domain V. Small insertions and deletions are represented in the repetitive domain. There is a stop codon after amino acid position 110 in the repetitive domain of LMW-34, indicating that it is a pseudogene. The other four genes have complete open reading frames and the putative mature regions of these genes were subcloned into pET-30a expression vector and successfully expressed in Escherichia coli. Protein sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that all proteins expressed in E. coli by the four genes could be related to B-group LMW glutenin subunits of wheat.