Apparent sources of the A genomes of wheats inferred from polymorphism in abundance and restriction fragment length of repeated nucleotide sequences

Dvořák, Jan; McGuire, Patrick E.; Cassidy, B. G.

doi:10.1139/g88-115

Cited by 291 publications

(158 citation statements)

References 18 publications

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“…DNA extraction was performed from leaves of the parental lines and each of the 93 RILs as described before (Dvorak et al, 1988). Different primer combinations based on published sequences (Hessler et al, 2002;van Mechelen et al, 1999) were used to amplify preferentially each of the wheat sequences orthologous to barley LoxA, LoxB, or LoxC genes.…”

Section: Molecular Methodsmentioning

confidence: 99%

A deletion at the Lpx-B1 locus is associated with low lipoxygenase activity and improved pasta color in durum wheat (Triticum turgidum ssp. durum)

Carrera

Echenique

Zhang

et al. 2007

Journal of Cereal Science

115

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The concentration of yellow carotenoid pigments in durum wheat grain is an important quality criterion and is determined both by their accumulation and by their degradation by lipoxygenase enzymes (Lpx loci). The existence of a duplication at the Lpx-B1 locus and the allelic variation for a deletion of the Lpx-B1.1 copy is reported. This deletion was associated with a 4.5-fold reduction in lipoxygenase activity and improved pasta color (Po0.0001) but not semolina color, suggesting reduced pigment degradation during pasta processing. A molecular marker for the deletion was mapped on chromosome 4B in a population obtained from the cross between durum line UC1113 and variety Kofa. A second lipoxygenase locus, designated Lpx-A3, was mapped on the homoeologous region on chromosome 4A and was associated with semolina and pasta color (Po0.01) but not with lipoxygenase activity in the mature grain. Selection for both the UC1113 allele for Lpx-A3 and the Kofa Lpx-B1.1 deletion resulted in a 10% increase in yellow scores for dry pasta relative to the opposite allele combination. This result indicates that the markers and the new allelic variants reported here will be useful tools to manipulate the wheat Lpx loci and to improve pasta color. r

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Section: Molecular Methodsmentioning

confidence: 99%

A deletion at the Lpx-B1 locus is associated with low lipoxygenase activity and improved pasta color in durum wheat (Triticum turgidum ssp. durum)

Carrera

Echenique

Zhang

et al. 2007

Journal of Cereal Science

115

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“…Probes and RFLP procedures DNA extraction and procedures for Southern blots and hybridization were as described before (Dvorak et al 1988;Dubcovsky et al 1994). Clones used in this study were selected from wheat ESTs from contigs mapped on deletion BIN 6BS5 located proximal to the Nor secondary constriction (http:// wheat.pw.usda.gov), from RFLP probes previously mapped in this region (Marino et al 1996;Mingeot and Jacquemin 1999), and from wheat ESTs similar to the colinear region in rice (A. Distelfeld et al in preparation).…”

Section: Methodsmentioning

confidence: 99%

Precise mapping of a locus affecting grain protein content in durum wheat

et al. 2003

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Grain protein content (GPC) is an important factor in pasta and breadmaking quality, and in human nutrition. It is also an important trait for wheat growers because premium prices are frequently paid for wheat with high GPC. A promising source for alleles to increase GPC was detected on chromosome 6B of Triticum turgidum var. dicoccoides accession FA-15-3 (DIC). Two previous quantitative trait locus (QTL) studies found that the positive effect of DIC-6B was associated to a single locus located between the centromere and the Nor-B2 locus on the short arm of chromosome 6B. Microsatellite markers Xgwm508 and Xgwm193 flanking the QTL region were used in this study to develop 20 new homozygous recombinant substitution lines (RSLs) with crossovers between these markers. These 20 RSLs, plus nine RSLs developed in previous studies were characterized with four new RFLP markers located within this chromosome segment. Grain protein content was determined in three field experiments organized as randomized complete block designs with ten replications each. The QTL peaks for protein content were located in the central region of a 2.7-cM interval between RFLP markers Xcdo365 and Xucw67 in the three experiments. Statistical analyses showed that almost all lines could be classified unequivocally within low-and high-protein groups, facilitating the mapping of this trait as a single Mendelian locus designated Gpc-6B1. The Gpc-6B1 locus was mapped 1.5-cM proximal to Xcdo365 and 1.2-cM distal to Xucw67. These new markers can be used to reduce the size of the DIC chromosome segment selected in markerassisted selection programs. Markers Nor-B2 and Xucw66 flanking the previous two markers can be used to select against the DIC segment and reduce the linkage drag during the transfer of Gpc-6B1 into commercial bread and pasta wheat varieties. The precise mapping of the high GPC gene, the high frequency of recombinants recovered in the targeted region, and the recent development of a tetraploid BAC library including the Gpc-6B1 DIC allele are the first steps towards the map-based cloning of this gene.

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“…An aliquot of the RNA sample was separated on a non-denaturing agarose gel to assess its integrity. Genomic DNA was isolated from leaves of nullisomic-tetrasomic and ditelosomic wheat lines as previously described (Dvorak et al, 1988).…”

Section: Rna and Genomic Dna Isolationmentioning

confidence: 99%

Cloning and comparative analysis of carotenoid β-hydroxylase genes provides new insights into carotenoid metabolism in tetraploid (Triticum turgidum ssp. durum) and hexaploid (Triticum aestivum) wheat grains

Qin

Zhang²,

Dubcovsky³

et al. 2012

Plant Mol Biol

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Carotenoid β-hydroxylases attach hydroxyl groups to the β-ionone rings (β-rings) of carotenoid substrates, resulting in modified structures and functions of carotenoid molecules. We cloned and characterized two genes (each with three homeologs), HYD1 and HYD2, which encode β-hydroxylases in wheat. The results from bioinformatic and nested degenerate PCR analyses collectively suggest that HYD1 and HYD2 may represent the entire complement of non-heme diiron β-hydroxylases in wheat. The homeologs of wheat HYDs exhibited major β-ring and minor ε-ring hydroxylation activities in carotenoid-accumulating E. coli strains. Distinct expression patterns were observed for different HYD genes and homeologs in vegetative tissues and developing grains of tetraploid and hexaploid wheat, suggesting their functional divergence and differential regulatory control in tissue-, grain development-, and ploidy-specific manners. An intriguing observation was that the expression of HYD1, particularly HYD-B1, reached highest levels at the last stage of tetraploid and hexaploid grain development, suggesting that carotenoids (at least xanthophylls) were still actively synthesized in mature grains. This result challenges the common perception that carotenoids are simply being turned over during wheat grain development after their initial biosynthesis at the early grain development stages. Overall, this improved understanding of carotenoid biosynthetic gene expression and carotenoid metabolism in wheat grains will contribute to the improvement of the nutritional value of wheat grains for human consumption.

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Apparent sources of the A genomes of wheats inferred from polymorphism in abundance and restriction fragment length of repeated nucleotide sequences

Cited by 291 publications

References 18 publications

A deletion at the Lpx-B1 locus is associated with low lipoxygenase activity and improved pasta color in durum wheat (Triticum turgidum ssp. durum)

A deletion at the Lpx-B1 locus is associated with low lipoxygenase activity and improved pasta color in durum wheat (Triticum turgidum ssp. durum)

Precise mapping of a locus affecting grain protein content in durum wheat

Cloning and comparative analysis of carotenoid β-hydroxylase genes provides new insights into carotenoid metabolism in tetraploid (Triticum turgidum ssp. durum) and hexaploid (Triticum aestivum) wheat grains

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