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New insights into the organization, recombination, expression and functional mechanism of low molecular weight glutenin subunit genes in bread wheat.

Dong L, Zhang X, Liu D, Fan H, Sun J, Zhang Z, Qin H, Li B, Hao S, Li Z, Wang D, Zhang A, Ling HQ - PLoS ONE (2010)

Bottom Line: Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality).This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat.Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The bread-making quality of wheat is strongly influenced by multiple low molecular weight glutenin subunit (LMW-GS) proteins expressed in the seeds. However, the organization, recombination and expression of LMW-GS genes and their functional mechanism in bread-making are not well understood. Here we report a systematic molecular analysis of LMW-GS genes located at the orthologous Glu-3 loci (Glu-A3, B3 and D3) of bread wheat using complementary approaches (genome wide characterization of gene members, expression profiling, proteomic analysis). Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality). Molecular mapping and recombination analyses revealed that the three Glu-3 loci of Xiaoyan 54 harbored dissimilar numbers of LMW-GS genes and covered different genetic distances. The number of expressed LMW-GS in the seeds was higher in Xiaoyan 54 than in Jing 411 (with relatively poor bread-making quality). This correlated with the finding of higher numbers of active LMW-GS genes at the A3 and D3 loci in Xiaoyan 54. Association analysis using recombinant inbred lines suggested that positive interactions, conferred by genetic combinations of the Glu-3 locus alleles with more numerous active LMW-GS genes, were generally important for the recombinant progenies to attain high Zeleny sedimentation value (ZSV), an important indicator of bread-making quality. A higher number of active LMW-GS genes tended to lead to a more elevated ZSV, although this tendency was influenced by genetic background. This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat. Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding.

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Related in: MedlinePlus

The organizations of LMW-GS genes of Xiaoyan 54 in 13 representative BAC clones.Diagrams illustrating the organizations of the LMW-GS genes (including both active and inactive members) of Xiaoyan 54 in 13 representative BAC clones, in relation to the markers (SFR159 and WHS179) and genes (LrK10, Pm3 analog, TdLRR-1B disease resistance gene, and the gene encoding GPI-anchored protein) found in the vicinities of LMW-GS genes in previous studies. Sequence gaps exist in the BAC clone B57-6-5 (drawn as a dashed line). The remaining 12 BAC clones were fully sequenced. If available, the physical distances (kb) between two neighboring genes or between a marker and its adjacent gene are given (in purple). The arrows indicate the predicted transcriptional directions of the genes. (A) The organization patterns of three Glu-A3 LMW-GS gene members. A WHS179 marker was present in BAC clone A1056-11-5, and its physical distance to A3-1 was 1.5 kb. A3-2 and A3-3 occur in the BAC contig Ctg708 formed by three BAC clones (A708-12-2, A1380-8-2, A1154-1-1). (B) The organization patterns of three Glu-B3 LMW-GS gene members (B3-1, B3-2, B3-3). The physical distances between neighboring genes or the adjacent gene and marker were not determined in B57-6-5 because of the presence of sequence gaps. (C) Organization patterns of seven Glu-D3 LMW-GS gene members (D3-1, D3-2, D3-3, D3-4, D3-5, D3-6, D3-7). D3-1 was found in the contig Ctg357 composed of two BAC clones (D357-11-6, D78-6-8).
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pone-0013548-g001: The organizations of LMW-GS genes of Xiaoyan 54 in 13 representative BAC clones.Diagrams illustrating the organizations of the LMW-GS genes (including both active and inactive members) of Xiaoyan 54 in 13 representative BAC clones, in relation to the markers (SFR159 and WHS179) and genes (LrK10, Pm3 analog, TdLRR-1B disease resistance gene, and the gene encoding GPI-anchored protein) found in the vicinities of LMW-GS genes in previous studies. Sequence gaps exist in the BAC clone B57-6-5 (drawn as a dashed line). The remaining 12 BAC clones were fully sequenced. If available, the physical distances (kb) between two neighboring genes or between a marker and its adjacent gene are given (in purple). The arrows indicate the predicted transcriptional directions of the genes. (A) The organization patterns of three Glu-A3 LMW-GS gene members. A WHS179 marker was present in BAC clone A1056-11-5, and its physical distance to A3-1 was 1.5 kb. A3-2 and A3-3 occur in the BAC contig Ctg708 formed by three BAC clones (A708-12-2, A1380-8-2, A1154-1-1). (B) The organization patterns of three Glu-B3 LMW-GS gene members (B3-1, B3-2, B3-3). The physical distances between neighboring genes or the adjacent gene and marker were not determined in B57-6-5 because of the presence of sequence gaps. (C) Organization patterns of seven Glu-D3 LMW-GS gene members (D3-1, D3-2, D3-3, D3-4, D3-5, D3-6, D3-7). D3-1 was found in the contig Ctg357 composed of two BAC clones (D357-11-6, D78-6-8).

Mentions: Sequence analysis revealed that A708-12-2, A1380-8-2 and A1154-1-1 from chromosome 1A were overlapping BACs, which formed a contig (Ctg708, Figure 1A) of ∼210 kb and contained A3-2 and A3-3 (Figure 1A). The distance between A3-2 and A3-3 was 67.6 kb. By contrast, BAC clone A1056-11-5, containing A3-1 (Figure 1A), was a singleton. Within Ctg708, A3-2 and A3-3 were each closely associated with marker SFR159 (less than 4 kb between marker and gene). There were two Pm3 disease resistance gene analogs upstream of A3-2 and A3-3 (Figure 1A). WHS179 was present in A1056-11-5, but not found in Ctg708 (Figure 1A). Conceptual translation showed that A3-1 and A3-2 encoded m- and i-type subunits, respectively (Table 1). A3-3 represented an i-type subunit pseudogene because its coding region was disrupted by a premature stop codon (Table 1). The close relationship of SFR159 and the LMW-GS gene in Ctg708 resembled that at the Glu-Am3 locus of T. monococcum [27]. However, there were three LMW-GS genes at Glu-Am3 (TmGlu-A3-1, 2, 3), compared to the two LMW-GS genes in Ctg708. To test if there was another LMW-GS gene located adjacent to Ctg708, a genomic PCR experiment was conducted using primers specific for i-type LMW-GS gene sequences (Table S1). After cloning and sequencing the amplified fragments, a third i-type LMW-GS gene sequence, sharing more than 88% nucleotide identity to A3-2 and A3-3, was identified. This newly identified LMW-GS gene (A3-4, accession number FJ755305) contained an intact ORF, giving rise to an i-type subunit upon conceptual translation (Table 1).


New insights into the organization, recombination, expression and functional mechanism of low molecular weight glutenin subunit genes in bread wheat.

Dong L, Zhang X, Liu D, Fan H, Sun J, Zhang Z, Qin H, Li B, Hao S, Li Z, Wang D, Zhang A, Ling HQ - PLoS ONE (2010)

The organizations of LMW-GS genes of Xiaoyan 54 in 13 representative BAC clones.Diagrams illustrating the organizations of the LMW-GS genes (including both active and inactive members) of Xiaoyan 54 in 13 representative BAC clones, in relation to the markers (SFR159 and WHS179) and genes (LrK10, Pm3 analog, TdLRR-1B disease resistance gene, and the gene encoding GPI-anchored protein) found in the vicinities of LMW-GS genes in previous studies. Sequence gaps exist in the BAC clone B57-6-5 (drawn as a dashed line). The remaining 12 BAC clones were fully sequenced. If available, the physical distances (kb) between two neighboring genes or between a marker and its adjacent gene are given (in purple). The arrows indicate the predicted transcriptional directions of the genes. (A) The organization patterns of three Glu-A3 LMW-GS gene members. A WHS179 marker was present in BAC clone A1056-11-5, and its physical distance to A3-1 was 1.5 kb. A3-2 and A3-3 occur in the BAC contig Ctg708 formed by three BAC clones (A708-12-2, A1380-8-2, A1154-1-1). (B) The organization patterns of three Glu-B3 LMW-GS gene members (B3-1, B3-2, B3-3). The physical distances between neighboring genes or the adjacent gene and marker were not determined in B57-6-5 because of the presence of sequence gaps. (C) Organization patterns of seven Glu-D3 LMW-GS gene members (D3-1, D3-2, D3-3, D3-4, D3-5, D3-6, D3-7). D3-1 was found in the contig Ctg357 composed of two BAC clones (D357-11-6, D78-6-8).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2958824&req=5

pone-0013548-g001: The organizations of LMW-GS genes of Xiaoyan 54 in 13 representative BAC clones.Diagrams illustrating the organizations of the LMW-GS genes (including both active and inactive members) of Xiaoyan 54 in 13 representative BAC clones, in relation to the markers (SFR159 and WHS179) and genes (LrK10, Pm3 analog, TdLRR-1B disease resistance gene, and the gene encoding GPI-anchored protein) found in the vicinities of LMW-GS genes in previous studies. Sequence gaps exist in the BAC clone B57-6-5 (drawn as a dashed line). The remaining 12 BAC clones were fully sequenced. If available, the physical distances (kb) between two neighboring genes or between a marker and its adjacent gene are given (in purple). The arrows indicate the predicted transcriptional directions of the genes. (A) The organization patterns of three Glu-A3 LMW-GS gene members. A WHS179 marker was present in BAC clone A1056-11-5, and its physical distance to A3-1 was 1.5 kb. A3-2 and A3-3 occur in the BAC contig Ctg708 formed by three BAC clones (A708-12-2, A1380-8-2, A1154-1-1). (B) The organization patterns of three Glu-B3 LMW-GS gene members (B3-1, B3-2, B3-3). The physical distances between neighboring genes or the adjacent gene and marker were not determined in B57-6-5 because of the presence of sequence gaps. (C) Organization patterns of seven Glu-D3 LMW-GS gene members (D3-1, D3-2, D3-3, D3-4, D3-5, D3-6, D3-7). D3-1 was found in the contig Ctg357 composed of two BAC clones (D357-11-6, D78-6-8).
Mentions: Sequence analysis revealed that A708-12-2, A1380-8-2 and A1154-1-1 from chromosome 1A were overlapping BACs, which formed a contig (Ctg708, Figure 1A) of ∼210 kb and contained A3-2 and A3-3 (Figure 1A). The distance between A3-2 and A3-3 was 67.6 kb. By contrast, BAC clone A1056-11-5, containing A3-1 (Figure 1A), was a singleton. Within Ctg708, A3-2 and A3-3 were each closely associated with marker SFR159 (less than 4 kb between marker and gene). There were two Pm3 disease resistance gene analogs upstream of A3-2 and A3-3 (Figure 1A). WHS179 was present in A1056-11-5, but not found in Ctg708 (Figure 1A). Conceptual translation showed that A3-1 and A3-2 encoded m- and i-type subunits, respectively (Table 1). A3-3 represented an i-type subunit pseudogene because its coding region was disrupted by a premature stop codon (Table 1). The close relationship of SFR159 and the LMW-GS gene in Ctg708 resembled that at the Glu-Am3 locus of T. monococcum [27]. However, there were three LMW-GS genes at Glu-Am3 (TmGlu-A3-1, 2, 3), compared to the two LMW-GS genes in Ctg708. To test if there was another LMW-GS gene located adjacent to Ctg708, a genomic PCR experiment was conducted using primers specific for i-type LMW-GS gene sequences (Table S1). After cloning and sequencing the amplified fragments, a third i-type LMW-GS gene sequence, sharing more than 88% nucleotide identity to A3-2 and A3-3, was identified. This newly identified LMW-GS gene (A3-4, accession number FJ755305) contained an intact ORF, giving rise to an i-type subunit upon conceptual translation (Table 1).

Bottom Line: Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality).This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat.Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
The bread-making quality of wheat is strongly influenced by multiple low molecular weight glutenin subunit (LMW-GS) proteins expressed in the seeds. However, the organization, recombination and expression of LMW-GS genes and their functional mechanism in bread-making are not well understood. Here we report a systematic molecular analysis of LMW-GS genes located at the orthologous Glu-3 loci (Glu-A3, B3 and D3) of bread wheat using complementary approaches (genome wide characterization of gene members, expression profiling, proteomic analysis). Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality). Molecular mapping and recombination analyses revealed that the three Glu-3 loci of Xiaoyan 54 harbored dissimilar numbers of LMW-GS genes and covered different genetic distances. The number of expressed LMW-GS in the seeds was higher in Xiaoyan 54 than in Jing 411 (with relatively poor bread-making quality). This correlated with the finding of higher numbers of active LMW-GS genes at the A3 and D3 loci in Xiaoyan 54. Association analysis using recombinant inbred lines suggested that positive interactions, conferred by genetic combinations of the Glu-3 locus alleles with more numerous active LMW-GS genes, were generally important for the recombinant progenies to attain high Zeleny sedimentation value (ZSV), an important indicator of bread-making quality. A higher number of active LMW-GS genes tended to lead to a more elevated ZSV, although this tendency was influenced by genetic background. This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat. Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding.

Show MeSH
Related in: MedlinePlus