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Xu W, Li Y, Li Y, Liu C, Wang Y, Xia G, Wang M. Asymmetric Somatic Hybridization Affects Synonymous Codon Usage Bias in Wheat. Front Genet 2021; 12:682324. [PMID: 34178040 PMCID: PMC8226224 DOI: 10.3389/fgene.2021.682324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/07/2021] [Indexed: 11/24/2022] Open
Abstract
Asymmetric somatic hybridization is an efficient strategy for crop breeding by introducing exogenous chromatin fragments, which leads to whole genomic shock and local chromosomal shock that induces genome-wide genetic variation including indel (insertion and deletion) and nucleotide substitution. Nucleotide substitution causes synonymous codon usage bias (SCUB), an indicator of genomic mutation and natural selection. However, how asymmetric somatic hybridization affects SCUB has not been addressed. Here, we explored this issue by comparing expressed sequence tags of a common wheat cultivar and its asymmetric somatic hybrid line. Asymmetric somatic hybridization affected SCUB and promoted the bias to A- and T-ending synonymous codon (SCs). SCUB frequencies in chromosomes introgressed with exogenous fragments were comparable to those in chromosomes without exogenous fragments, showing that exogenous fragments had no local chromosomal effect. Asymmetric somatic hybridization affected SCUB frequencies in indel-flanking sequences more strongly than in non-flanking sequences, and this stronger effect was present in both chromosomes with and without exogenous fragments. DNA methylation-driven SCUB shift was more pronounced than other SC pairs. SCUB shift was similar among seven groups of allelic chromosomes as well as three sub-genomes. Our work demonstrates that the SCUB shift induced by asymmetric somatic hybridization is attributed to the whole genomic shock, and DNA methylation is a putative force of SCUB shift during asymmetric somatic hybridization. Asymmetric somatic hybridization provides an available method for deepening the nature of SCUB shift and genetic variation induced by genomic shock.
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Affiliation(s)
- Wenjing Xu
- The Key Laboratory of Plant Development and Environmental Adaption, Ministry of Education, School of Life Science, Shandong University, Jinan, China
| | - Yingchun Li
- The Key Laboratory of Plant Development and Environmental Adaption, Ministry of Education, School of Life Science, Shandong University, Jinan, China
| | - Yajing Li
- The Key Laboratory of Plant Development and Environmental Adaption, Ministry of Education, School of Life Science, Shandong University, Jinan, China
| | - Chun Liu
- The Key Laboratory of Plant Development and Environmental Adaption, Ministry of Education, School of Life Science, Shandong University, Jinan, China
| | - Yanxia Wang
- Shijiazhuang Academy of Agriculture and Forestry Sciences, Shijiazhuang, China
| | - Guangmin Xia
- The Key Laboratory of Plant Development and Environmental Adaption, Ministry of Education, School of Life Science, Shandong University, Jinan, China
| | - Mengcheng Wang
- The Key Laboratory of Plant Development and Environmental Adaption, Ministry of Education, School of Life Science, Shandong University, Jinan, China
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Wang M, Ji Y, Feng S, Liu C, Xiao Z, Wang X, Wang Y, Xia G. The non-random patterns of genetic variation induced by asymmetric somatic hybridization in wheat. BMC PLANT BIOLOGY 2018; 18:244. [PMID: 30332989 PMCID: PMC6192298 DOI: 10.1186/s12870-018-1474-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/05/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Asymmetric somatic hybridization is an efficient crop breeding approach by introducing several exogenous chromatin fragments, which leads to genomic shock and therefore induces genome-wide genetic variation. However, the fundamental question concerning the genetic variation such as whether it occurs randomly and suffers from selection pressure remains unknown. RESULTS Here, we explored this issue by comparing expressed sequence tags of a common wheat cultivar and its asymmetric somatic hybrid line. Both nucleotide substitutions and indels (insertions and deletions) had lower frequencies in coding sequences than in un-translated regions. The frequencies of nucleotide substitutions and indels were both comparable between chromosomes with and without introgressed fragments. Nucleotide substitutions distributed unevenly and were preferential to indel-flanking sequences, and the frequency of nucleotide substitutions at 5'-flanking sequences of indels was obviously higher in chromosomes with introgressed fragments than in those without exogenous fragment. Nucleotide substitutions and indels both had various frequencies among seven groups of allelic chromosomes, and the frequencies of nucleotide substitutions were strongly negatively correlative to those of indels. Among three sets of genomes, the frequencies of nucleotide substitutions and indels were both heterogeneous, and the frequencies of nucleotide substitutions exhibited drastically positive correlation to those of indels. CONCLUSIONS Our work demonstrates that the genetic variation induced by asymmetric somatic hybridization is attributed to both whole genomic shock and local chromosomal shock, which is a predetermined and non-random genetic event being closely associated with selection pressure. Asymmetric somatic hybrids provide a worthwhile model to further investigate the nature of genomic shock induced genetic variation.
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Affiliation(s)
- Mengcheng Wang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100 People’s Republic of China
| | - Yujie Ji
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095 China
| | - Shiting Feng
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100 People’s Republic of China
| | - Chun Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100 People’s Republic of China
| | - Zhen Xiao
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100 People’s Republic of China
| | - Xiaoping Wang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100 People’s Republic of China
| | - Yanxia Wang
- Shijiazhuang Academy of Agriculture and Forestry Sciences, Shijiazhuang, 050041 China
| | - Guangmin Xia
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, Shandong 250100 People’s Republic of China
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Wang D, Zhang K, Dong L, Dong Z, Li Y, Hussain A, Zhai H. Molecular genetic and genomic analysis of wheat milling and end-use traits in China: Progress and perspectives. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.cj.2017.10.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Tanaka H, Nabeuchi C, Kurogaki M, Garg M, Saito M, Ishikawa G, Nakamura T, Tsujimoto H. A novel compensating wheat- Thinopyrum elongatum Robertsonian translocation line with a positive effect on flour quality. BREEDING SCIENCE 2017; 67:509-517. [PMID: 29398945 PMCID: PMC5790049 DOI: 10.1270/jsbbs.17058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 09/14/2017] [Indexed: 05/30/2023]
Abstract
Wheat flours are used to produce bread, pasta, breakfast cereals, and biscuits; the various properties of these end-products are attributed to the gluten content, produced as seed storage proteins in the wheat endosperm. Thus, genes encoding gluten protein are major targets of wheat breeders aiming to improve the various properties of wheat flour. Here, we describe a novel compensating wheat-Thinopyrum elongatum Robertsonian translocation (T1AS.1EL) line involving the short arm of wheat chromosome 1A (1AS) and the long arm of Th. elongatum chromosome 1E (1EL); we developed this line through centric breakage-fusion. Compared to the common wheat cultivars Chinese Spring and Norin 61, we detected two additional 1EL-derived high-molecular-weight glutenin subunits (HMW-GSs) in the T1AS.1EL plants. Based on the results of an SDS-sedimentation volume to estimate the gluten strength of T1AS.1EL-derived flour, we predict that T1AS.1EL-derived flour is better suited to bread-making than Chinese Spring- and Norin 61-derived flour and that this is because of its greater gluten diversity. Also, we were able to assign 33 of 121 wheat PCR-based Landmark Unique Gene markers to chromosome 1E of Th. elongatum. These markers can now be used for further chromosome engineering of the Th. elongatum segment of T1AS.1EL.
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Affiliation(s)
- Hiroyuki Tanaka
- Laboratory of Plant Genetics, Faculty of Agriculture, Tottori University,
Tottori 680-8553,
Japan
| | - Chisato Nabeuchi
- Laboratory of Plant Genetics, Faculty of Agriculture, Tottori University,
Tottori 680-8553,
Japan
| | - Misaki Kurogaki
- Laboratory of Plant Genetics, Faculty of Agriculture, Tottori University,
Tottori 680-8553,
Japan
| | - Monika Garg
- National Agri-food Biotechnology Institute,
Punjab 160-071,
India
| | - Mika Saito
- NARO Tohoku National Agriculture Research Center,
Iwate 020-0198,
Japan
| | - Goro Ishikawa
- NARO Tohoku National Agriculture Research Center,
Iwate 020-0198,
Japan
- NARO Institute of Crop Science,
Tsukuba, Ibaraki 305-8518,
Japan
| | - Toshiki Nakamura
- NARO Tohoku National Agriculture Research Center,
Iwate 020-0198,
Japan
| | - Hisashi Tsujimoto
- Laboratory of Molecular Breeding, Arid Land Research Center, Tottori University,
Tottori 680-0001,
Japan
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5
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Wang M, Liu C, Xing T, Wang Y, Xia G. Asymmetric somatic hybridization induces point mutations and indels in wheat. BMC Genomics 2015; 16:807. [PMID: 26476565 PMCID: PMC4609470 DOI: 10.1186/s12864-015-1974-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 10/03/2015] [Indexed: 01/06/2023] Open
Abstract
Background Allopolyploid genome needs wide structural variation to deal with genomic shock. The introgression line, generated via asymmetric somatic hybridization, is introgressed with a minimum of exogenous chromatin, which also leads to genomic shock to induce genetic variation. However, the extent of its genomic variation and its difference from allopolyploidies remains unknown. Methods Here, we explored this issue using the bread wheat cultivar SR3, a derivative of an asymmetric somatic hybrid between the cultivar JN177 and an accession of tall wheatgrass (Thinopyrum elongatum). The ESTs (expressed sequence taqs) were large-scale sequenced using the cDNA library constructed in each of SR3 and JN177. Point mutations and indels (insertions and deletions) of SR3 were calculated, and their difference from the genetic variation of bread wheat and its ancestors were compared, with aim to analyze the extent and pattern of sequence variation induced by somatic hybridization. Results Both point mutations and indels (insertions and deletions) were frequently induced by somatic hybridization in the coding sequences. While the genomic shock caused by allopolyploidization tends to favor deletion over insertion, there was no evidence for such a preference following asymmetric somatic hybridization. The GC content of sequence adjacent to indel sites was also distinct from what has been observed in allopolyploids. Conclusions This study demonstrates that asymmetric somatic hybridization induces high frequency of genetic variation in a manner partially different from allopolipoidization. Asymmetric somatic hybridization provides appropriate material to comprehensively explore the nature of the genetic variation induced by genomic shock. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1974-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mengcheng Wang
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, 250100, Shandong, P. R. China.
| | - Chun Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, 250100, Shandong, P. R. China.
| | - Tian Xing
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, 250100, Shandong, P. R. China
| | - Yanxia Wang
- Shijiazhuang Academy of Agriculture and Forestry Sciences, 479 Shengli North Avenue, Shijiazhuang, 050041, Hebei, China
| | - Guangmin Xia
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 27 Shandanan Road, Jinan, 250100, Shandong, P. R. China.
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Liu S, Li F, Kong L, Sun Y, Qin L, Chen S, Cui H, Huang Y, Xia G. Genetic and epigenetic changes in somatic hybrid introgression lines between wheat and tall wheatgrass. Genetics 2015; 199:1035-45. [PMID: 25670745 PMCID: PMC4391570 DOI: 10.1534/genetics.114.174094] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 02/05/2015] [Indexed: 12/27/2022] Open
Abstract
Broad phenotypic variations were induced in derivatives of an asymmetric somatic hybridization of bread wheat (Triticum aestivum) and tall wheatgrass (Thinopyrum ponticum Podp); however, how these variations occurred was unknown. We explored the nature of these variations by cytogenetic assays and DNA profiling techniques to characterize six genetically stable somatic introgression lines. Karyotyping results show the six lines similar to their wheat parent, but GISH analysis identified the presence of a number of short introgressed tall wheatgrass chromatin segments. DNA profiling revealed many genetic and epigenetic differences, including sequences deletions, altered regulation of gene expression, changed patterns of cytosine methylation, and the reactivation of retrotransposons. Phenotypic variations appear to result from altered repetitive sequences combined with the epigenetic regulation of gene expression and/or retrotransposon transposition. The extent of genetic and epigenetic variation due to the maintenance of parent wheat cells in tissue culture was assessed and shown to be considerably lower than had been induced in the introgression lines. Asymmetric somatic hybridization provides appropriate material to explore the nature of the genetic and epigenetic variations induced by genomic shock.
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Affiliation(s)
- Shuwei Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
| | - Fei Li
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
| | - Lina Kong
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
| | - Yang Sun
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
| | - Lumin Qin
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
| | - Suiyun Chen
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
| | - Haifeng Cui
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
| | - Yinghua Huang
- U.S. Department of Agriculture/Agricultural Research Service Plant Science Research Laboratory, Stillwater, Oklahoma 74075
| | - Guangmin Xia
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan 250100, Peoples' Republic of China
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7
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Liu S, Xia G. The place of asymmetric somatic hybridization in wheat breeding. PLANT CELL REPORTS 2014; 33:595-603. [PMID: 24370665 DOI: 10.1007/s00299-013-1552-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 12/04/2013] [Accepted: 12/10/2013] [Indexed: 05/08/2023]
Abstract
Since its first development some 40 years ago, the application of the somatic hybridization technique has generated a body of hybrid plant material involving a wide combination of parental species. Until the late 1990s, the technique was ineffective in wheat, as regeneration from protoplasts was proving difficult to achieve. Since this time, however, a successful somatic hybridization protocol for wheat has been established and used to generate a substantial number of both symmetric and asymmetric somatic hybrids and derived materials, especially involving the parental combination bread wheat and tall wheatgrass (Thinopyrum ponticum). This review describes the current state of the art for somatic hybridization in wheat and focuses on its potential application for wheat improvement.
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Affiliation(s)
- Shuwei Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Sciences, Shandong University, Jinan, 250100, China
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8
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CHEN FANGUO, YANG LIANG, ZHAO FENG, MIN HAOXIANG, XIA GUANGMIN. Molecular cloning and variation of ω-gliadin genes from a somatic hybrid introgression line II-12 and parents (Triticum aestivum cv. Jinan 177 and Agropyron elongatum). J Genet 2011; 90:137-42. [DOI: 10.1007/s12041-011-0039-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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Gao X, Liu SW, Sun Q, Xia GM. High frequency of HMW-GS sequence variation through somatic hybridization between Agropyron elongatum and common wheat. PLANTA 2010; 231:245-250. [PMID: 19902245 DOI: 10.1007/s00425-009-1040-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 10/13/2009] [Indexed: 05/28/2023]
Abstract
A symmetric somatic hybridization was performed to combine the protoplasts of tall wheatgrass (Agropyron elongatum) and bread wheat (Triticum aestivum). Fertile regenerants were obtained which were morphologically similar to tall wheatgrass, but which contained some introgression segments from wheat. An SDS-PAGE analysis showed that a number of non-parental high-molecular weight glutenin subunits (HMW-GS) were present in the symmetric somatic hybridization derivatives. These sequences were amplified, cloned and sequenced, to deliver 14 distinct HMW-GS coding sequences, eight of which were of the y-type (Hy1-Hy8) and six x-type (Hx1-Hx6). Five of the cloned HMW-GS sequences were successfully expressed in E. coli. The analysis of their deduced peptide sequences showed that they all possessed the typical HMW-GS primary structure. Sequence alignments indicated that Hx5 and Hy1 were probably derived from the tall wheatgrass genes Aex5 and Aey6, while Hy2, Hy3, Hx1 and Hy6 may have resulted from slippage in the replication of a related biparental gene. We found that both symmetric and asymmetric somatic hybridization could promote the emergence of novel alleles. We discussed the origination of allelic variation of HMW-GS genes in somatic hybridization, which might be the result from the response to genomic shock triggered by the merger and interaction of biparent genomes.
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Affiliation(s)
- Xin Gao
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, 250100 Jinan, People's Republic of China
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10
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Xia G. Progress of chromosome engineering mediated by asymmetric somatic hybridization. J Genet Genomics 2009; 36:547-56. [PMID: 19782956 DOI: 10.1016/s1673-8527(08)60146-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Revised: 06/02/2009] [Accepted: 07/15/2009] [Indexed: 11/27/2022]
Abstract
Plant somatic hybridization has progressed steadily over the past 35 years. Many hybrid plants have been generated from fusion combinations of different phylogenetic species, some of which have been utilized in crop breeding programs. Among them, asymmetric hybrid, which usually contains a fraction of alien genome, has received more attention because of its importance in crop improvement. However, few studies have dealt with the heredity of the genome of somatic hybrid for a long time, which has limited the progress of this approach. Over recent ten years, along with the development of an effective cytogenetical tool "in situ hybridization (ISH)", asymmetric fusion of common wheat (Triticum aestivum L.) with different grasses or cereals has been greatly developed. Genetics, genomes, functional genes and agricultural traits of wheat asymmetric hybrids have been subject to systematic investigations using gene cloning, genomic in situ hybridization (GISH) and molecular makers. The future goal is to fully elucidate the functional relationships among improved agronomic traits, the genes and underlying molecular mechanisms, and the genome dynamics of somatic introgression lines. This will accelerate the development of elite germplasms via somatic hybridization and the application of these materials in the molecular improvement of crop plants.
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Affiliation(s)
- Guangmin Xia
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation of Education Ministry, School of Life Sciences, Shandong University, Jinan 250100, China.
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Chen F, Zhao F, Xu C, Xia G. 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. J Genet Genomics 2009; 35:743-9. [PMID: 19103430 DOI: 10.1016/s1673-8527(08)60230-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 08/02/2008] [Accepted: 09/21/2008] [Indexed: 10/21/2022]
Abstract
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 remaining 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 domain. 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.
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Affiliation(s)
- Fanguo Chen
- School of Life Science, Shandong University, Jinan 250100, China
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12
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Liu H, Liu S, Xia G. Generation of high frequency of novel alleles of the high molecular weight glutenin in somatic hybridization between bread wheat and tall wheatgrass. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2009; 118:1193-1198. [PMID: 19199095 DOI: 10.1007/s00122-009-0973-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 01/15/2009] [Indexed: 05/27/2023]
Abstract
Somatic hybridization between bread wheat and tall wheatgrass (Agropyron elongatum) has generated fertile introgression progenies with novel combinations of high molecular weight glutenin subunits (HMW-GS). Most of these novel HMW-GS alleles were stably inherited. Sixteen HMW-GS sequences were PCR amplified from three introgression progeny lines and sequenced. The alignment of these sequences indicated that five, probably derived from point mutations of the parental genes, whereas eight likely represent the product of replication slippage. Three Glu-1Ay sequences appear to have lost the transposon presented in the parental gene. Two subunits carry an additional cysteine residue, which may be favorable to the quality of end-use product. We demonstrate that novel HMW-GS alleles can be rapidly generated via asymmetric somatic hybridization.
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Affiliation(s)
- Heng Liu
- The Key Laboratory of Plant Cell Engineering and Germplasm Innovation of the Ministry of Education, School of Life Science, Shandong University, 250100, Jinan, People's Republic of China
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13
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Cui H, Yu Z, Deng J, Gao X, Sun Y, Xia G. Introgression of bread wheat chromatin into tall wheatgrass via somatic hybridization. PLANTA 2009; 229:323-330. [PMID: 18985381 DOI: 10.1007/s00425-008-0832-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 09/29/2008] [Indexed: 05/27/2023]
Abstract
Regenerates were obtained following somatic hybridization between tall wheatgrass (Agropyron elongatum) and bread wheat (Triticum aestivum cv. Jinan177) protoplasts. Two lines (CU and XI) were self-fertile in the first (R0) and subsequent (R1 and R2) generations. The phenotype of each R1 population was uniform. All CU progeny were phenotypically similar to the tall wheatgrass parent, while XI progeny had thinner, smoother and softer leaves. Cytological analysis showed that more wheat chromatin was present in the hybrid callus than in the R1 and R2 plants, and that some intercalary translocations of wheat chromosome segments were retained in the R2 generation. AFLP profiling confirmed the presence of wheat DNA in the introgression lines. Analysis of the high molecular weight glutenin subunit content of derived seed identified three novel subunits, not present in either the wheat or the tall wheatgrass parent. Microsatellite-based profiling of the chloroplast genome of the introgression lines suggested that only chloroplast sequences from the tall wheatgrass parent were present. The specifically inherited phenomena and possible application of these hybrids are discussed.
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Affiliation(s)
- Haifeng Cui
- School of Life Sciences, Shandong University, 27 Shandanan Road, 250100, Jinan, People's Republic of China
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14
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Liu S, Gao X, Xia G. Characterizing HMW-GS alleles of decaploid Agropyron elongatum in relation to evolution and wheat breeding. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2008; 116:325-34. [PMID: 17992503 PMCID: PMC2226004 DOI: 10.1007/s00122-007-0669-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Accepted: 10/23/2007] [Indexed: 05/13/2023]
Abstract
Bread wheat quality is mainly correlated with high molecular weight glutenin subunits (HMW-GS) of endosperm. The number of HMW-GS alleles with good processing quality is limited in bread wheat cultivars, while there are plenty of HMW-GS alleles in wheat-related grasses to exploit. We report here on the cloning and characterization of HMW-GS alleles from the decaploid Agropyron elongatum. Eleven novel HMW-GS alleles were cloned from the grass. Of them, five are x-type and six y-type glutenin subunit genes. Three alleles Aex4, Aey7, and Aey9 showed high similarity with another three alleles from the diploid Lophopyrum elongatum, which provided direct evidence for the Ee genome origination of A. elongatum. It was noted that C-terminal regions of three alleles of the y-type genes Aey8, Aey9, and Aey10 showed more similarity with x-type genes than with other y-type genes. This demonstrates that there is a kind of intermediate state that appeared in the divergence between x- and y-type genes in the HMW-GS evolution. One x-type subunit, Aex4, with an additional cysteine residue, was speculated to be correlated with the good processing quality of wheat introgression lines. Aey4 was deduced to be a chimeric gene from the recombination between another two genes. How the HMW-GS genes of A. elongatum may contribute to the improvement of wheat processing quality are discussed.
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Affiliation(s)
- Shuwei Liu
- School of Life Sciences, Shandong University, 250100 Jinan, People’s Republic of China
| | - Xin Gao
- School of Life Sciences, Shandong University, 250100 Jinan, People’s Republic of China
| | - Guangmin Xia
- School of Life Sciences, Shandong University, 250100 Jinan, People’s Republic of China
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15
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Allen GC, Flores-Vergara MA, Krasynanski S, Kumar S, Thompson WF. A modified protocol for rapid DNA isolation from plant tissues using cetyltrimethylammonium bromide. Nat Protoc 2007; 1:2320-5. [PMID: 17406474 DOI: 10.1038/nprot.2006.384] [Citation(s) in RCA: 605] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We describe a modification of the DNA extraction method, in which cetyltrimethylammonium bromide (CTAB) is used to extract nucleic acids from plant tissues. In contrast to the original method, the modified CTAB procedure is faster, omits the selective precipitation and CsCl gradient steps, uses less expensive and toxic reagents, requires only inexpensive laboratory equipment and is more readily adapted to high-throughput DNA extraction. This protocol yields approximately 5-30 microg of total DNA from 200 mg of tissue fresh weight, depending on plant species and tissue source. It can be completed in as little as 5-6 h.
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Affiliation(s)
- G C Allen
- Department of Horticultural Science and Crop Science, 1200 Partners II, Campus Box 7550, 840 Main Campus Drive, North Carolina State University, Raleigh, NC 27606-7550, USA.
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Generation of novel high quality HMW-GS genes in two introgression lines of Triticum aestivum/Agropyron elongatum. BMC Evol Biol 2007; 7:76. [PMID: 17502002 PMCID: PMC1884143 DOI: 10.1186/1471-2148-7-76] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Accepted: 05/15/2007] [Indexed: 12/02/2022] Open
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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Luo Z, Chen F, Feng D, Xia G. LMW-GS genes in Agropyron elongatum and their potential value in wheat breeding. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2005; 111:272-80. [PMID: 15926075 DOI: 10.1007/s00122-005-2021-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Accepted: 03/29/2005] [Indexed: 05/02/2023]
Abstract
To study the usefulness of low-molecular-weight glutenin subunits (LMW-GS) of Agropyron elongatum (Host) Nevski to wheat (Triticum aestivum L.) quality improvement, we characterized LMW-GS genes of A. elongatum. Nine LMW-GS genes of A. elongatum, which were named AeL1 to AeL9, were cloned by genomic PCR. After sequencing, we obtained complete open reading frames from AeL2 to AeL8 and partial genes of AeL1 and AeL9. All nine sequences are homoeologous to those of wheat and related grasses. Comparison of the deduced amino acid sequences with those of published LMW-GS suggests that the basic structures of all the subunits are very similar. However, except for AeL4 and AeL5, which contain the identical N-terminal sequence with LMW-m, other LMW-GS sequences separated from A. elongatum cannot be classified according to previous criteria for the three types: LMW-m (methionine), LMW-s (serine), and LMW-i (isoleucine), and then 12 groups. In addition, there are some characters in the LMW-GS sequences of A. elongatum: AeL2, AeL3, and AeL6 involve a Cys residue in the signal peptide respectively, which is absent in most of LMW-GS; AeL3, AeL6, AeL8, and AeL9 start their first Cys residues in the N-terminal repetitive domains, respectively; both AeL2 and AeL5 have nine Cys residues, with an extra Cys residue in the N-terminal repetitive domain and the repetitive and glutamine-rich domain; AeL2, AeL3, AeL6, and AeL9 comprise long repetitive domains. Phylogenetic analysis indicates that there is a relatively weak sequence identity between the LMW-GS genes from A. elongatum cloned in this study and those reported from other plants. Three LMW-GS sequences, AeL2, AeL3, and AeL6, are clustered to Glu-A3 from wheat than to those from other plants. The possible use of these genes in relation to the high quality of hybrid wheat is discussed.
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Affiliation(s)
- Zhen Luo
- School of Life Sciences, Shandong University, Jinan, PR China
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