Microsatellite mapping of the genes for sham ramification and extra glume in spikelets of tetraploid wheat

Abstract Polyploidy occurs prevalently and plays an important role during plant speciation and evolution. This phenomenon suggests polyploidy could develop novel features that enable them to adapt wider range of environmental conditions compared with diploid progenitors. Bread wheat (Triticum aestivum L., BBAADD) is a typical allohexaploid species and generally exhibits greater salt tolerance than its tetraploid wheat progenitor (BBAA). However, little is known about the underlying molecular basis and the regulatory pathway of this trait. Here, we show that the histone acetyltransferase TaHAG1 acts as a crucial regulator to strengthen salt tolerance of hexaploid wheat. Salinity-induced TaHAG1 expression was associated with tolerance variation in polyploidy wheat. Overexpression, silencing and CRISPR-mediated knockout of TaHAG1 validated the role of TaHAG1 in salinity tolerance of wheat. TaHAG1 contributed to salt tolerance by modulating ROS production and signal specificity. Moreover, TaHAG1 directly targeted a subset of genes that are responsible for hydrogen peroxide production, and enrichment of TaHAG1 triggered increased H3 acetylation and transcriptional upregulation of these loci under salt stress. In addition, we found the salinity-induced TaHAG1-mediated ROS production pathway is involved in salt tolerance difference of wheat accessions with varying ploidy. Our findings provide insight into the molecular mechanism of how an epigenetic regulatory factor facilitates adaptability of polyploidy wheat and highlights this epigenetic modulator as a strategy for salt tolerance breeding in bread wheat.

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Function and evolution of allelic variation of Sr13 conferring resistance to stem rust in tetraploid wheat ( Triticum turgidum L.)

The Plant Journal ◽

10.1111/tpj.15263 ◽

2021 ◽

Author(s):

Baljeet K. Gill ◽

Daryl L. Klindworth ◽

Matthew N. Rouse ◽

Jinglun Zhang ◽

Qijun Zhang ◽

...

Keyword(s):

Stem Rust ◽

Triticum Turgidum ◽

Allelic Variation ◽

Tetraploid Wheat

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The Independent Domestication of Timopheev’s Wheat: Insights from Haplotype Analysis of the Brittle rachis 1 (BTR1-A) Gene

Genes ◽

10.3390/genes12030338 ◽

2021 ◽

Vol 12 (3) ◽

pp. 338

Author(s):

Moran Nave ◽

Mihriban Taş ◽

John Raupp ◽

Vijay K. Tiwari ◽

Hakan Ozkan ◽

...

Keyword(s):

Promoter Region ◽

Haplotype Analysis ◽

Common Ancestor ◽

Triticum Turgidum ◽

Tetraploid Wheat ◽

Wheat Species ◽

Loss Of Function ◽

Brittle Rachis ◽

Gene Level ◽

Large Panel

Triticum turgidum and T. timopheevii are two tetraploid wheat species sharing T. urartu as a common ancestor, and domesticated accessions from both of these allopolyploids exhibit nonbrittle rachis (i.e., nonshattering spikes). We previously described the loss-of-function mutations in the Brittle Rachis 1 genes BTR1-A and BTR1-B in the A and B subgenomes, respectively, that are responsible for this most visible domestication trait in T. turgidum. Resequencing of a large panel of wild and domesticated T. turgidum accessions subsequently led to the identification of the two progenitor haplotypes of the btr1-A and btr1-B domesticated alleles. Here, we extended the haplotype analysis to other T. turgidum subspecies and to the BTR1 homologues in the related T. timopheevii species. Our results showed that all the domesticated wheat subspecies within T. turgidum share common BTR1-A and BTR1-B haplotypes, confirming their common origin. In T. timopheevii, however, we identified a novel loss-of-function btr1-A allele underlying a partially brittle spike phenotype. This novel recessive allele appeared fixed within the pool of domesticated Timopheev’s wheat but was also carried by one wild timopheevii accession exhibiting partial brittleness. The promoter region for BTR1-B could not be amplified in any T. timopheevii accessions with any T. turgidum primer combination, exemplifying the gene-level distance between the two species. Altogether, our results support the concept of independent domestication processes for the two polyploid, wheat-related species.

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Genetically Divergent Types of the Wheat Leaf Fungus Puccinia triticina in Ethiopia, a Center of Tetraploid Wheat Diversity

Phytopathology ◽

10.1094/phyto-10-15-0247-r ◽

2016 ◽

Vol 106 (4) ◽

pp. 380-385 ◽

Cited By ~ 10

Author(s):

J. A. Kolmer ◽

M. A. Acevedo

Keyword(s):

Leaf Rust ◽

Common Wheat ◽

Hexaploid Wheat ◽

Rust Fungus ◽

Tetraploid Wheat ◽

Low Frequency ◽

Puccinia Triticina ◽

Leaf Rust Resistance ◽

Virulence Phenotype ◽

Wheat Leaf

Collections of Puccinia triticina, the wheat leaf rust fungus, were obtained from tetraploid and hexaploid wheat in the central highlands of Ethiopia, and a smaller number from Kenya, from 2011 to 2013, in order to determine the genetic diversity of this wheat pathogen in a center of host diversity. Single-uredinial isolates were derived and tested for virulence phenotype to 20 lines of Thatcher wheat that differ for single leaf rust resistance genes and for molecular genotypes with 10 simple sequence repeat (SSR) primers. Nine virulence phenotypes were described among the 193 isolates tested for virulence. Phenotype BBBQJ, found only in Ethiopia, was predominantly collected from tetraploid wheat. Phenotype EEEEE, also found only in Ethiopia, was exclusively collected from tetraploid wheat and was avirulent to the susceptible hexaploid wheat ‘Thatcher’. Phenotypes MBDSS and MCDSS, found in both Ethiopia and Kenya, were predominantly collected from common wheat. Phenotypes CCMSS, CCPSS, and CBMSS were found in Ethiopia from common wheat at low frequency. Phenotypes TCBSS and TCBSQ were found on durum wheat and common wheat in Kenya. Four groups of distinct SSR genotypes were described among the 48 isolates genotyped. Isolates with phenotypes BBBQJ and EEEEE were in two distinct SSR groups, and isolates with phenotypes MBDSS and MCDSS were in a third group. Isolates with CCMSS, CCPSS, CBMSS, TCBSS, and TCBSQ phenotypes were in a fourth SSR genotype group. The diverse host environment of Ethiopia has selected and maintained a genetically divergent population of P. triticina.

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Composition of and variation in high- and low-molecular weight glutenin subunits, and omega gliadins in Ethiopian tetraploid wheat germplasm

Plant Genetic Resources ◽

10.1079/pgr2006110 ◽

2006 ◽

Vol 4 (2) ◽

pp. 134-143 ◽

Cited By ~ 7

Author(s):

Faris Hailu ◽

Eva Johansson ◽

Arnulf Merker ◽

Getachew Belay ◽

Harjit-Singh ◽

...

Keyword(s):

Molecular Weight ◽

Tetraploid Wheat ◽

Glutenin Subunit ◽

Low Molecular Weight ◽

Glutenin Subunits ◽

Hmw Glutenin Subunits ◽

Lmw Glutenin Subunits ◽

Hmw Glutenin ◽

Omega Gliadins ◽

High Degree

A collection of 120 Ethiopian tetraploid wheat accessions was analysed for high-molecular weight (HMW) glutenin subunit, low-molecular weight (LMW) glutenin subunit and omega gliadin composition by SDS–PAGE. For the HMW glutenin subunits, a new allelic variant, 2****, was detected which has not been previously described at the Glu-A1 locus. A high proportion of Glu-A1x banding pattern was observed in durum wheat. For the Glu-B1 locus four different banding patterns were detected. Among those HMW glutenin subunits, 7+8 were the most common, while subunits 14+15 and 6+8 were found to be rare. A high degree of variation was evident for the LMW glutenin subunits and D-zone omega gliadins. The association of the composition of the gluten with quality has been discussed. This wide variation can be used in improving the quality of wheat and to widen its genetic base.

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