Differentiation between homoeologous chromosomes 1A of wheat and 1Am of Triticum monococcum and its recognition by the wheat Ph1 locus.

Bread wheat is an allohexaploid that behaves as a diploid during meiosis, the cell division process to produce the gametes occurring in organisms with sexual reproduction. Knowledge of the mechanisms implicated in meiosis can contribute to facilitating the transfer of desirable traits from related species into a crop like wheat in the framework of breeding. It is particularly interesting to shed light on the mechanisms controlling correct pairing between homologous (equivalent) chromosomes and recombination, even more in polyploid species. The Ph1 (Pairing homoeologous 1) locus is implicated in recombination. In this work, we aimed to study whether homoeologous (equivalent chromosomes from different genomes) Hordeum chilense (wild barley) and H. vulgare (cultivated barley) chromosomes can associate and recombine during meiosis in the wheat background in the absence of the Ph1 locus. For this, we have developed H. chilense and H. vulgare double monosomic addition lines for the same and for different homoeology group in wheat in the ph1b mutant background. Using genomic in situ hybridization, we visualized the two (wild and cultivated) barley chromosomes during meiosis and we studied the processes of recognition, association, and recombination between homoeologous chromosomes in the absence of the Ph1 locus. Our results showed that the Ph1 locus does not prevent homoeologous chromosome pairing but it can regulate recombination.

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Recognition of Homeology by the Wheat Ph1 Locus

Genetics ◽

10.1093/genetics/144.3.1195 ◽

1996 ◽

Vol 144 (3) ◽

pp. 1195-1203 ◽

Cited By ~ 1

Author(s):

Ming-Cheng Luo ◽

Jorge Dubcovsky ◽

Jan Dvořák

Keyword(s):

Chromosome Pairing ◽

Mitotic Spindle ◽

Triticum Monococcum ◽

Entire Length ◽

Homologous Chromosomes ◽

Chromosome Alignment ◽

Homeologous Chromosome ◽

Ph1 Locus ◽

As If

Abstract Chromosome 1Am of Triticum monococcum is closely homeologous to T. aestivum chromosome 1A but recombines with it little in the presence of the wheat suppressor of homeologous chromosome pairing, Ph1. In the absence of Ph1, the two chromosomes recombine as if they were completely homologous. Chromosomes having either terminal or interstitial segments of chromosome 1Am in 1A were constructed and their recombination with 1A was investigated in the presence of Ph1. No recombination was detected in the homeologous (1Am/1A) segments, irrespective of whether terminally or interstitially positioned in a chromosome, whereas the levels of recombination in the juxtaposed homologous (1A/1A) segments was normal or close to normal relative to completely homologous 1A chromosomes. These observations show that Ph1 does not regulate chromosome pairing by premeiotic chromosome alignment and a mitotic spindle-centromere interaction, as has been suggested, but processes homology along the entire length of chromosomes.

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Centromere association is an unlikely mechanism by which the wheat Ph1 locus regulates metaphase I chromosome pairing between homoeologous chromosomes

Chromosoma ◽

10.1007/s004120000093 ◽

2000 ◽

Vol 109 (6) ◽

pp. 410-414 ◽

Cited By ~ 16

Author(s):

Jan Dvorak ◽

Adam J. Lukaszewski

Keyword(s):

Chromosome Pairing ◽

Ph1 Locus ◽

Homoeologous Chromosomes ◽

Metaphase I

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Homoeologous Chromosomes From Two Hordeum Species Can Recognize and Associate During Meiosis in Wheat in the Presence of the Ph1 Locus

Frontiers in Plant Science ◽

10.3389/fpls.2018.00585 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 2

Author(s):

María C. Calderón ◽

María-Dolores Rey ◽

Antonio Martín ◽

Pilar Prieto

Keyword(s):

Ph1 Locus ◽

Hordeum Species ◽

Homoeologous Chromosomes

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Triticum monococcum: Zair, W.

IUCN Red List of Threatened Species ◽

10.2305/iucn.uk.2017-3.rlts.t172116a19398350.en ◽

2016 ◽

Author(s):

Keyword(s):

Triticum Monococcum

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Stripe rust resistance gene Yr34 (synonym Yr48) is located within a distal translocation of Triticum monococcum chromosome 5AmL into common wheat

Theoretical and Applied Genetics ◽

10.1007/s00122-021-03816-z ◽

2021 ◽

Author(s):

Shisheng Chen ◽

Joshua Hegarty ◽

Tao Shen ◽

Lei Hua ◽

Hongna Li ◽

...

Keyword(s):

Resistance Gene ◽

Common Wheat ◽

Stripe Rust ◽

Rust Resistance ◽

Triticum Monococcum ◽

Rust Resistance Gene ◽

Stripe Rust Resistance ◽

Polyploid Wheat ◽

Stripe Rust Resistance Gene ◽

A Genome

AbstractKey messageThe stripe rust resistance geneYr34 was transferred to polyploid wheat chromosome 5AL from T. monococcumand has been used for over two centuries.Wheat stripe (or yellow) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is currently among the most damaging fungal diseases of wheat worldwide. In this study, we report that the stripe rust resistance gene Yr34 (synonym Yr48) is located within a distal segment of the cultivated Triticum monococcum subsp. monococcum chromosome 5AmL translocated to chromosome 5AL in polyploid wheat. The diploid wheat species Triticum monococcum (genome AmAm) is closely related to T. urartu (donor of the A genome to polyploid wheat) and has good levels of resistance against the stripe rust pathogen. When present in hexaploid wheat, the T. monococcum Yr34 resistance gene confers a moderate level of resistance against virulent Pst races present in California and the virulent Chinese race CYR34. In a survey of 1,442 common wheat genotypes, we identified 5AmL translocations of fourteen different lengths in 17.5% of the accessions, with higher frequencies in Europe than in other continents. The old European wheat variety “Mediterranean” was identified as a putative source of this translocation, suggesting that Yr34 has been used for over 200 years. Finally, we designed diagnostic CAPS and sequenced-based markers that will be useful to accelerate the deployment of Yr34 in wheat breeding programs to improve resistance to this devastating pathogen.

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Search for atoxic cereals: a single blind, cross-over study on the safety of a single dose of Triticum monococcum, in patients with celiac disease

BMC Gastroenterology ◽

10.1186/1471-230x-13-92 ◽

2013 ◽

Vol 13 (1) ◽

Cited By ~ 14

Author(s):

Barbara Zanini ◽

Beatrice Petroboni ◽

Tarcisio Not ◽

Nicola Di Toro ◽

Vincenzo Villanacci ◽

...

Keyword(s):

Celiac Disease ◽

Single Dose ◽

Triticum Monococcum ◽

Single Blind

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Effect of Triticum monococcum glutenin loci on cookie making quality and on predictive tests for bread making quality

Journal of Cereal Science ◽

10.1006/jcrs.2001.0448 ◽

2002 ◽

Vol 36 (1) ◽

pp. 9-18 ◽

Cited By ~ 16

Author(s):

G. Tranquilli ◽

M. Cuniberti ◽

M.C. Gianibelli ◽

L. Bullrich ◽

O.R. Larroque ◽

...

Keyword(s):

Triticum Monococcum ◽

Bread Making ◽

Predictive Tests

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PrBn, a Major Gene Controlling Homeologous Pairing in Oilseed Rape (Brassica napus) Haploids

Genetics ◽

10.1093/genetics/164.2.645 ◽

2003 ◽

Vol 164 (2) ◽

pp. 645-653 ◽

Cited By ~ 4

Author(s):

Eric Jenczewski ◽

Frédérique Eber ◽

Agnès Grimaud ◽

Sylvie Huet ◽

Marie Odile Lucas ◽

...

Keyword(s):

Brassica Napus ◽

Oilseed Rape ◽

Chromosome Pairing ◽

Major Gene ◽

Major Effect ◽

F1 Hybrids ◽

Precise Control ◽

Ph1 Locus ◽

Likelihood Approach ◽

Likelihood Ratio Statistics

Abstract Precise control of chromosome pairing is vital for conferring meiotic, and hence reproductive, stability in sexually reproducing polyploids. Apart from the Ph1 locus of wheat that suppresses homeologous pairing, little is known about the activity of genes that contribute to the cytological diploidization of allopolyploids. In oilseed rape (Brassica napus) haploids, the amount of chromosome pairing at metaphase I (MI) of meiosis varies depending on the varieties the haploids originate from. In this study, we combined a segregation analysis with a maximum-likelihood approach to demonstrate that this variation is genetically based and controlled mainly by a gene with a major effect. A total of 244 haploids were produced from F1 hybrids between a high- and a low-pairing variety (at the haploid stage) and their meiotic behavior at MI was characterized. Likelihood-ratio statistics were used to demonstrate that the distribution of the number of univalents among these haploids was consistent with the segregation of a diallelic major gene, presumably in a background of polygenic variation. Our observations suggest that this gene, named PrBn, is different from Ph1 and could thus provide complementary information on the meiotic stabilization of chromosome pairing in allopolyploid species.

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