Generation of novel high quality HMW-GS genes in two introgression lines of Triticum aestivum/Agropyron elongatum.
BACKGROUND
High molecular weight glutenin subunits (HMW-GS) have been proved to be mostly correlated with the processing quality of common wheat (Triticum aestivum). But wheat cultivars have limited number of high quality HMW-GS. However, novel HMW-GS were found to be present in many wheat asymmetric somatic hybrid introgression lines of common wheat/Agropyron elongatum.


RESULTS
To exploit how these new subunits were generated, we isolated HMW-GS genes from two sib hybrid lines (II-12 and 11-4-6) and compared them with those from their parents. The result shows that two genes of hybrid (H11-3-3 and H11-4-3) are directly introgressed from the donor parent Agropyron elongatum; one hybrid gene (H1Dx5) comes from point mutation of a parental wheat gene (1Dx2.1); two other hybrid genes (H1By8 and H1By16) are likely resulting from unequal crossover or slippage of a parental wheat gene (1By9.1); and the sixth novel hybrid gene (H1Dy12) may come from recombination between two parental genes.


CONCLUSIONS
Therefore, we demonstrate that novel HMW-GS genes can be rapidly created through asymmetric somatic hybridization in a manner similar with the evolution mechanism of these genes supposed before. We also described gene shuffling as a new mechanism of novel HMW-GS gene formation in hybrids. The results suggest that asymmetric somatic hybridization is an important approach for widening HMW-GS genebank of wheat quality improvement.
Liu
Shuwei
S
School of Life Sciences, Shandong University, Jinan, PR China. liushuwei@126.com <liushuwei@126.com>
Zhao
Shuangyi
S
Chen
Fanguo
F
Xia
Guangmin
G
D031702:Agropyron / Q000235:genetics*; D001483:Base Sequence; D003062:Codon; D017124:Conserved Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D017343:Genes, Plant; D005983:Glutens / Q000235:genetics*; D006824:Hybridization, Genetic; D008970:Molecular Weight; D017354:Point Mutation; D021122:Protein Subunits / Q000235:genetics*; D014908:Triticum / Q000235:genetics*
D003062:Codon; D021122:Protein Subunits; D005983:Glutens; C037302:glutenin