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Generation of novel high quality HMW-GS genes in two introgression lines of Triticum aestivum/Agropyron elongatum.

Liu S, Zhao S, Chen F, Xia G - BMC Evol. Biol. (2007)

Bottom Line: High molecular weight glutenin subunits (HMW-GS) have been proved to be mostly correlated with the processing quality of common wheat (Triticum aestivum).However, novel HMW-GS were found to be present in many wheat asymmetric somatic hybrid introgression lines of common wheat/Agropyron elongatum.The results suggest that asymmetric somatic hybridization is an important approach for widening HMW-GS genebank of wheat quality improvement.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Life Sciences, Shandong University, Jinan, PR China. liushuwei@126.com <liushuwei@126.com>

ABSTRACT

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.

Conclusion: 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.

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Phylogenetic analysis of HMW-GS genes cloned from hybrids and both parents. The Neighbor-Joining tree is constructed through MEGA program (Version 3.1).
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Figure 3: Phylogenetic analysis of HMW-GS genes cloned from hybrids and both parents. The Neighbor-Joining tree is constructed through MEGA program (Version 3.1).

Mentions: H11-3-3 and H11-4-3 of hybrid wheat 11-4-6 displayed a high similarity with Aey1 and Aex4 of A. elongatum, but low similarity with all HMW-GS alleles of Jinan177 (Figure 3), which confirmed that these two sequences might be transferred from A. elongatum to hybrid wheat genome during somatic hybridization. GISH analysis of hybrid wheat genome in our lab revealed that different hybrid lines had different sites of translocation or insertion of chromatin [29,30]. Wang et al. [31] located introgression small-chromosome-segments of A. elongatum on hybrid wheat chromosomes 2AL, 1BL, 5BS, 1DL, 2DL and 6DS, using GISH/FISH/SSR analysis combined with karyotype data. However, there is no direct evidence concerning the hybrid introgression line contains gene from donor on the molecular level. The sequence data of these two genes provided further evidence that asymmetric somatic hybridization can transfer alien gene(s) from donor to the receptor genome, and the potential as a genetic/genomic tool for crop improvements.


Generation of novel high quality HMW-GS genes in two introgression lines of Triticum aestivum/Agropyron elongatum.

Liu S, Zhao S, Chen F, Xia G - BMC Evol. Biol. (2007)

Phylogenetic analysis of HMW-GS genes cloned from hybrids and both parents. The Neighbor-Joining tree is constructed through MEGA program (Version 3.1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1884143&req=5

Figure 3: Phylogenetic analysis of HMW-GS genes cloned from hybrids and both parents. The Neighbor-Joining tree is constructed through MEGA program (Version 3.1).
Mentions: H11-3-3 and H11-4-3 of hybrid wheat 11-4-6 displayed a high similarity with Aey1 and Aex4 of A. elongatum, but low similarity with all HMW-GS alleles of Jinan177 (Figure 3), which confirmed that these two sequences might be transferred from A. elongatum to hybrid wheat genome during somatic hybridization. GISH analysis of hybrid wheat genome in our lab revealed that different hybrid lines had different sites of translocation or insertion of chromatin [29,30]. Wang et al. [31] located introgression small-chromosome-segments of A. elongatum on hybrid wheat chromosomes 2AL, 1BL, 5BS, 1DL, 2DL and 6DS, using GISH/FISH/SSR analysis combined with karyotype data. However, there is no direct evidence concerning the hybrid introgression line contains gene from donor on the molecular level. The sequence data of these two genes provided further evidence that asymmetric somatic hybridization can transfer alien gene(s) from donor to the receptor genome, and the potential as a genetic/genomic tool for crop improvements.

Bottom Line: High molecular weight glutenin subunits (HMW-GS) have been proved to be mostly correlated with the processing quality of common wheat (Triticum aestivum).However, novel HMW-GS were found to be present in many wheat asymmetric somatic hybrid introgression lines of common wheat/Agropyron elongatum.The results suggest that asymmetric somatic hybridization is an important approach for widening HMW-GS genebank of wheat quality improvement.

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Life Sciences, Shandong University, Jinan, PR China. liushuwei@126.com <liushuwei@126.com>

ABSTRACT

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.

Conclusion: 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.

Show MeSH