Molecular characterization of LMW-GS genes from a somatic hybrid introgression line Ⅱ-12 between Triticum aestivum and Agropyron elongatum in relation to quick evolution

摘要

In order to exploit the evolution and find novel low-molecular-weight glutenin subunit(LMW-GS) for improvement of common wheat quality,thirteen variants from a somatic hybrid introgression line Ⅱ-12 between Triticum aestivum cv.Jinan 177(JN177) and Agropyron elongatum were characterized via genomic PCR.Four clones were pseudogenes because they contained an internal stop codon.The re-maining nine variants contained intact open reading frames(ORFs).Sequence alignment indicates that the proteins deduced from the nine ORFs have similar primary structure with LMW-GS cloned from its parents previously.However,they have some unique modifications in the structures.For example,EU292737 contains not only an extra Cys residue in the C-terminal domain but also a long repetitive do-main.Both EU159511 and EU292738 start their first Cys residue in the N-terminal repetitive domain,but not in the N-conserved domain traditionally.These structural alterations may have positive contributions to wheat flour quality.The results of phylogeny showed that most LMW-GS variances from Ⅱ-12 were homologous to those from parent JN177 and other wheat lines.The reason for quick evolution of LMW-GS in Ⅱ-12 was discussed.