The organization of genes tightly linked to the Ha locus in Aegilops tauschii, the D-genome donor to wheat

The grain hardness locus, Ha, is located at the distal end of the short arm of chromosome 5D in wheat. Three polypeptides, puroindoline-a, puroindoline-b, and grain softness protein (GSP-1), have been identified as components of friabilin, a biochemical marker for grain softness, and the genes for these polypeptides are known to be tightly linked to the Ha locus. However, this region of the chromosome 5D has not been well characterized and the physical distance between the markers is not known. Separate lambda clones containing the puroindoline-a gene and the puroindoline-b gene have been isolated from an Aegilops tauschii (the donor of the D genome to wheat) genomic lambda library and investigated. Considerable variation appears to exist in the organization of the region upstream of the gene for puroindoline-b among species closely related to wheat. Using in situ hybridization the genes for puroindoline-a, -b, and GSP-1 were demonstrated to be physically located at the tip of the short arm of chromosome 5 of A. tauschii. Four overlapping clones were isolated from a large-insert BAC library constructed from A. tauschii and of these one contained genes for all of puroindoline-a, puroindoline-b, and GSP-1. The gene for puroindoline-a is located between the other two genes at a distance no greater than approximately 30 kb from either gene. The BAC clone containing all three known genes was used to screen a cDNA library constructed from hexaploid wheat and cDNAs that could encode novel polypeptides were isolated.Key words: puroindolines, GSP-1, chromosome 5D, BAC library, tauschii.

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Highly Recombinogenic Regions at Seed Storage Protein Loci on Chromosome 1DS of Aegilops tauschii, the D-Genome Donor of Wheat

Genetics ◽

10.1093/genetics/155.1.361 ◽

2000 ◽

Vol 155 (1) ◽

pp. 361-367 ◽

Cited By ~ 3

Author(s):

Wolfgang Spielmeyer ◽

Odile Moullet ◽

André Laroche ◽

Evans S Lagudah

Keyword(s):

Genetic Distance ◽

Storage Protein ◽

Seed Storage Protein ◽

Aegilops Tauschii ◽

Bac Library ◽

Seed Storage ◽

D Genome ◽

Rflp Map ◽

Genome Donor ◽

The Relationship

Abstract A detailed RFLP map was constructed of the distal end of the short arm of chromosome 1D of Aegilops tauschii, the diploid D-genome donor species of hexaploid wheat. Ae. tauschii was used to overcome some of the limitations commonly associated with molecular studies of wheat such as low levels of DNA polymorphism. Detection of multiple loci by most RFLP probes suggests that gene duplication events have occurred throughout this chromosomal region. Large DNA fragments isolated from a BAC library of Ae. tauschii were used to determine the relationship between physical and genetic distance at seed storage protein loci located at the distal end of chromosome 1DS. Highly recombinogenic regions were identified where the ratio of physical to genetic distance was estimated to be <20 kb/cM. These results are discussed in relation to the genome-wide estimate of the relationship between physical and genetic distance.

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The Ha locus of wheat: Identification of a polymorphic region for tracing grain hardness in crosses

Genome ◽

10.1139/g99-075 ◽

1999 ◽

Vol 42 (6) ◽

pp. 1242-1250 ◽

Cited By ~ 20

Author(s):

M Turner ◽

Y Mukai ◽

P Leroy ◽

B Charef ◽

R Appels ◽

...

Keyword(s):

Dna Sequences ◽

Hexaploid Wheat ◽

Aegilops Tauschii ◽

Grain Hardness ◽

High Sequence Identity ◽

D Genome ◽

Sequence Identity ◽

Group 5 ◽

Grain Softness ◽

Puroindoline A

The grain softness proteins or friabilins are known to be composed of three main components: puroindoline a, puroindoline b, and GSP-1. cDNAs for GSP-1 have previously been mapped to group-5 chromosomes and their location on chromosome 5D is closely linked to the grain hardness (Ha) locus of hexaploid wheat. A genomic DNA clone containing the GSP-1 gene (wGSP1-A1) from hexaploid wheat has been identified by fluorescent in situ hybridization as having originated from the distal end of the short arm of chromosome 5A. A genomic clone containing the gene (wGSP1-D1) was also isolated from Aegilops tauschii, the donor of the D genome to bread wheat. There are no introns in the GSP-1 genes, and there is high sequence identity between wGSP1-A1 and wGSP1-D1 up to 1 kb 5' and 300 bp 3' to wGSP1-D1. However, regions further upstream and downstream of wGSP1-D1 share no significant sequence identity to corresponding sequences in wGSP1-A1. These regions therefore identified potentially valuable sequences for tracing the Ha locus through assaying polymorphic DNA sequences. The sequence from 300 to 500 bp 3' to wGSP1-D1 (wGSP1-D13) was mapped to the Ha locus in a mapping population. wGSP1-D13 was also tightly linked to genes for puroindoline a and puroindoline b which have been previously mapped to be at the Ha locus. In addition wGSP1-D13 was used to detect RFLPs between near isogenic soft and hard Falcon lines and in a random selection of soft and hard wheats.Key words: wheat, grain hardness, chromosome 5, puroindoline, GSP-1.

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Dormancy Spreads Seed Germination over a Long Period with a Discontinuous Procession in Aegilops tauschii, the D-genome Donor Species of Bread Wheat

International Journal of Agricultural Research ◽

10.3923/ijar.2008.77.82 ◽

2007 ◽

Vol 3 (1) ◽

pp. 77-82 ◽

Cited By ~ 2

Author(s):

Qi-Jiao Chen ◽

Lian-Quan Zhang ◽

You-Wei Yang ◽

Zhong-Wei Yuan ◽

Zhi-Guo Xiang ◽

...

Keyword(s):

Seed Germination ◽

Bread Wheat ◽

Aegilops Tauschii ◽

D Genome ◽

Long Period ◽

Genome Donor ◽

Donor Species

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Exploring the origin of the D genome of oat by fluorescence in situ hybridization

Genome ◽

10.1139/gen-2014-0048 ◽

2014 ◽

Vol 57 (9) ◽

pp. 469-472 ◽

Cited By ~ 5

Author(s):

Xiaomei Luo ◽

Haiqin Zhang ◽

Houyang Kang ◽

Xing Fan ◽

Yi Wang ◽

...

Keyword(s):

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Avena Sativa ◽

Genetic Improvement ◽

Similar Distribution ◽

Diploid Progenitor ◽

D Genome ◽

Genome Donor ◽

Sequential Experiments

Further understanding of the origin of cultivated oat would accelerate its genetic improvement. In particular, it would be useful to clarify which diploid progenitor contributed the D genome of this allohexaploid species. In this study, we demonstrate that the landmarks produced by fluorescence in situ hybridization (FISH) of species of Avena using probes derived from Avena sativa can be used to explore the origin of the D genome. Selected sets of probes were hybridized in several sequential experiments performed on exactly the same chromosome spreads, with multiple probes of cytological preparations. Probes pITS and A3-19 showed there might be a similar distribution of pITS between the Ac and D genomes. These results indicated that the Ac genome is closely related to the D genome, and that Avena canariensis (AcAc) could be the D-genome donor of cultivated oat.

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The sugary-type isoamylase gene from rice and Aegilops tauschii: characterization and comparison with maize and Arabidopsis

Genome ◽

10.1139/g02-130 ◽

2003 ◽

Vol 46 (3) ◽

pp. 496-506 ◽

Cited By ~ 16

Author(s):

S Rahman ◽

Y Nakamura ◽

Z Li ◽

B Clarke ◽

N Fujita ◽

...

Keyword(s):

In Situ Hybridization ◽

Fluorescent In Situ Hybridization ◽

Aegilops Tauschii ◽

Rice Chromosome ◽

Proximal Region ◽

Chromosome 8 ◽

D Genome ◽

Debranching Enzyme ◽

Cdna Sequences

Genes for an isoamylase-like debranching enzyme have been isolated from rice and Aegilops tauschii, the donor of the D genome to wheat. The structures of the genes are very similar to each other and to the maize SU1 isoamylase gene and consist of 18 exons spread over approximately 7.5 kb. Southern analysis and fluorescent in situ hybridization showed the Ae. tauschii gene to be located in the proximal region of the short arm of chromosome 7D, thus showing synteny with the localization of the rice isoamylase gene on rice chromosome 8. Analysis of the expression pattern of wheat sugary isoamylase genes indicates that they are strongly expressed in the developing endosperm 6 days after flowering. Three distinct Sugary-type cDNA sequences were isolated from the wheat endosperm that are likely to correspond to the products of the three genomes. The deduced amino acid sequence of rice and wheat Sugary-type isoamylase is compared with other sequences available in the database and the results demonstrate that there are three types of isoamylase sequences in plants: those containing 18 exons (the Sugary-type isoamylase gene), those containing 21 exons, and those containing only 1 exon. It is possible that different combinations of isoamylase genes are expressed in different tissues.Key words: isoamylase, rice, wheat, sugary, FISH.

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Traits to Differentiate Lineages and Subspecies of Aegilops tauschii, the D Genome Progenitor Species of Bread Wheat

Diversity ◽

10.3390/d13050217 ◽

2021 ◽

Vol 13 (5) ◽

pp. 217

Author(s):

Mazin Mahjoob Mohamed Mahjoob ◽

Tai-Shen Chen ◽

Yasir Serag Alnor Gorafi ◽

Yuji Yamasaki ◽

Nasrein Mohamed Kamal ◽

...

Keyword(s):

Entire Range ◽

Aegilops Tauschii ◽

Triticum Aestivum L ◽

High Quality ◽

D Genome ◽

Physiological Diversity ◽

Phylogenetic Cluster ◽

High Quality Snps ◽

Genome Donor ◽

Passport Data

Aegilops tauschii Coss., the D genome donor of hexaploid wheat (Triticum aestivum L.), is the most promising resource used to broaden the genetic diversity of wheat. Taxonomical studies have classified Ae. tauschii into two subspecies, ssp. tauschii and ssp. strangulata. However, molecular analysis revealed three distantly related lineages, TauL1, TauL2 and TauL3. TauL1 and TauL3 includes the only ssp. tauschii, whereas TauL2 includes both subspecies. This study aimed to clarify the phylogeny of Ae. tauschii and to find the traits that can differentiate between TauL1, TauL2 and TauL3, or between ssp. tauschii and ssp. strangulata. We studied the genetic and morpho-physiological diversity in 293 accessions of Ae. tauschii, covering the entire range of the species. A total of 5880 high-quality SNPs derived from DArTseq were used for phylogenetic cluster analyses. As a result, we observed wide morpho-physiological variation in each lineage and subspecies. Despite this variation, no key traits can discriminate lineages or subspecies though some traits were significantly different. Of 124 accessions previously lacking the passport data, 66 were allocated to TauL1, 57 to TauL2, and one to TauL3.

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Genetic Characterization of Genetic Resources of <i>Aegilops tauschii</i>, Wheat D Genome Donor, Newly Collected in North Caucasia

American Journal of Plant Sciences ◽

10.4236/ajps.2017.811187 ◽

2017 ◽

Vol 08 (11) ◽

pp. 2769-2784

Author(s):

Ayaka Kakizaki ◽

Taihachi Kawahara ◽

Mikhail Alexandrovich Zhuk ◽

Tamara Nikolaevna Smekalova ◽

Kazuhiro Sato ◽

...

Keyword(s):

Genetic Resources ◽

Genetic Characterization ◽

Aegilops Tauschii ◽

D Genome ◽

Genome Donor

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A complex arrangement of genes at a starch branching enzyme I locus in the D-genome donor of wheat

Genome ◽

10.1139/g97-062 ◽

1997 ◽

Vol 40 (4) ◽

pp. 465-474 ◽

Cited By ~ 34

Author(s):

S. Rahman ◽

M. Morell ◽

R. Appels ◽

S. Abrahams ◽

D. Abbott ◽

...

Keyword(s):

In Situ Hybridization ◽

Branching Enzyme ◽

Starch Branching Enzyme ◽

D Genome ◽

Triticum Tauschii ◽

Putative Protein ◽

Genome Donor ◽

Opposite Strand ◽

Enzyme I

Genomic DNA fragments from Triticum tauschii (D-genome donor to wheat) carrying starch branching enzyme I (SBE I) type genes have been characterized. One fragment contains one complete gene and two partial genes in 16 kb of DNA. One of the partial genes is oriented in the opposite strand to the other two. The gene that is complete was sequenced. Its structure corresponds closely to that of rice in that exons 3–8 are retained at similar sizes and spacings. A cDNA closely corresponding to the complete gene was isolated and characterized; it codes for a putative protein that represents a novel type of SBE I, as it is shorter at the 3′ end than the forms reported so far in other plants. A second genomic fragment contains a different SBE I gene. There appear to be approximately 10 copies of SBE I type genes in wheat (approximately 5 in T. tauschii) and most of them have been assigned to group 7 chromosomes. In situ hybridization indicates that a major locus for the genes is located at the distal end of the short arm of chromosome 7D.Key words: starch, branching enzyme genes, wheat, Triticum tauschii, in situ hybridization.

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Systematic Comparisons of Orthologous Selenocysteine Methyltransferase and Homocysteine Methyltransferase Genes from Seven Monocots Species

Notulae Scientia Biologicae ◽

10.15835/nsb729491 ◽

2015 ◽

Vol 7 (2) ◽

pp. 210-216 ◽

Cited By ~ 3

Author(s):

De-yong ZHAO ◽

Fu-lai SUN ◽

Bo ZHANG ◽

Zhi-qiang ZHANG ◽

Long-quan YIN

Keyword(s):

Common Wheat ◽

Brachypodium Distachyon ◽

Aegilops Tauschii ◽

Selenium Deficiency ◽

D Genome ◽

Genome Donor ◽

A Genome ◽

Selenocysteine Methyltransferase ◽

Homocysteine Methyltransferase ◽

Plant Arabidopsis Thaliana

Identifying and manipulating genes underlying selenium metabolism could be helpful for increasing selenium content in crop grain, which is an important way to overcome diseases resulted from selenium deficiency. A reciprocal smallest distance algorithm (RSD) approach was applied using two experimentally confirmed Homocysteine S-Methyltransferases genes (HMT1 and HMT2) and a putative Selenocysteine Methyltransferase (SMT) from dicots plant Arabidopsis thaliana, to explore their orthologs in seven sequenced diploid monocot species: Oryza sativa, Zea mays, Sorghum bicolor, Brachypodium distachyon, Hordeum vulgare, Aegilops tauschii (the D-genome donor of common wheat) and Triticum urartu (the A-genome donor of common wheat). HMT1 was apparently diverged from HMT2 and most of SMT orthologs were the same with that of HMT2 in this study, leading to the hypothesis that SMT and HMT originate from one common ancestor gene. Identifying orthologs provide candidates for further experimental confirmation; also it could be helpful in designing primers to clone SMT or HMT orthologs in other crops.

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