Identification of a null allele at the Wx‐A1 locus in durum wheat (Triticum turgidum L. ssp. durum Desf.)

Vanzetti, Leonardo Sebastián; Pflüger, L. A.; Bainotti, Carlos Tomas; Jensen, C.; Helguera, Marcelo

doi:10.1111/j.1439-0523.2009.01741.x

Cited by 8 publications

(8 citation statements)

References 17 publications

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“…Buck Topacio, Vanzetti et al (2010) found that the absence of the Wx-A1 protein in that durum cultivar was associated with a 1-bp deletion in the sixth exon, resulting in a frameshift generating a stop codon. This allelic variant was catalogued as Wx-A1h.…”

Section: Variants Of Wx-a1 Genementioning

confidence: 99%

Wheat waxy proteins: polymorphism, molecular characterization and effects on starch properties

Guzmán

Álvarez

2015

Theor Appl Genet

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The starch fraction, comprising about 70% of the total dry matter in the wheat grain, can greatly affect the end-use quality of products made from wheat kernels, especially Asian noodles. Starch is associated with the shelf life and nutritional value (glycaemic index) of different wheat products. Starch quality is closely associated with the ratio of amylose to amylopectin, the two main macromolecules forming starch. In this review, we briefly summarise the discovery of waxy proteins-shown to be the sole enzymes responsible for amylose synthesis in wheat. The review particularly focuses on the different variants of these proteins, together with their molecular characterisation and evaluation of their effects on starch composition. There have been 19 different waxy protein variants described using protein electrophoresis; and at a molecular level 19, 15 and seven alleles described for Wx-A1, Wx-B1 and Wx-D1, respectively. This large variability, found in modern wheat and genetic resources such as wheat ancestors and wild relatives, is in some cases not properly ordered. The proper ordering of all the data generated is the key to enhancing use in breeding programmes of the current variability described, and thus generating wheat with novel starch properties to satisfy the demand of industry and consumers for novel high-quality processed food.

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Section: Variants Of Wx-a1 Genementioning

confidence: 99%

Wheat waxy proteins: polymorphism, molecular characterization and effects on starch properties

Guzmán

Álvarez

2015

Theor Appl Genet

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“…However, Astrodur did not show this deletion, but the null character is conferred by a single nucleotide deletion in exon-7, which produced a frameshift that generated a premature stop codon in the gene sequence. This mutation is the same as the one described by Vanzetti et al (2010) in the partial sequence of the Wx-A1h allele since the alignment of this partial sequence (458 bp; NCBI ID: GQ120523) shows a 100 % similarity with the Wx-A1 sequence in Astrodur (Fig. 2B), therefore, we classified this allele as putative Wx-A1h.…”

Section: Resultsmentioning

confidence: 94%

“…According to Vrinten et al (1999), null allele Wx-B1b is characterized by the deletion of the entire Wx gene, so the absence of amplicon corresponding to the B genome in cv. Blanqueta when the AFC/AR2 primers were used The asterisks indicate SNPs found in the 3'-UTR region and the arrow a non-synonymous substitution.…”

Section: Resultsmentioning

confidence: 99%

“…This study correctly detected and properly identified both alleles using specific molecular markers. However, it is important to note that wheat lines carrying the Wx-A1b allele would lead to a negative result for the markers designed by Vanzetti et al (2010) because they were designed to detect the Wx-A1h allele and vice versa for Wx-A1h allele detection using the markers designed by Nakamura et al (2002) for Wx-B1b detection.…”

Section: Discussionmentioning

confidence: 99%

“…The null character of this last allele is due to one single nucleotide deletion in exon-7, which produces a frameshift that leads to the appearance of a premature stop codon. In the Wx-A1b allele, the null character is the result of aberrant splicing derived from a 23-bp deletion, which cause the loss of 39 amino acids including part of the transit peptide and the ADP-glucose binding site (Vrinten et al 1999). Even though the presence of one or other allele would have identical effects on amylose content, a correct classification of the Wx alleles is very important if they are to be used in wheat breeding programs.…”

Section: Discussionmentioning

confidence: 99%

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Molecular characterization of several Wx alleles in durum wheat

Ortega¹,

Guzmán²,

Álvarez³

2015

Biologia plant.

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The Wx gene, which encodes waxy proteins, is the sole gene responsible for amylose synthesis in wheat seed endosperm. In this study, we characterized, at the molecular level, several Wx alleles in durum wheat (Triticum turgidum L. ssp. durum Desf.) that had previously been catalogued at the protein level. Our data show a misclassification of the alleles in both Wx genes: Wx-A1 alleles from Blanqueta (Wx-A1a) and Astrodur (Wx-A1b) have been reclassified as Wx-A1a and Wx-A1h, respectively. A sequence comparison of the Wx-B1e allele shows that there were up to five different alleles under this denomination, which confirms that the protein analysis by SDS-PAGE separation needs to be combined with the PCR amplification-sequencing analysis in order to obtain a correct classification of the alleles, which will facilitate their use in wheat quality improvement.

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Molecular characterization of waxy alleles in three subspecies of hexaploid wheat and identification of two novel Wx-B1 alleles

Ayala

Álvarez²,

Yamamori

et al. 2015

Theor Appl Genet

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Two novel Wx - B1 null alleles that enlarge the genetic variability for this wheat gene were characterized, whose effects on wheat quality could be different to those of the Wx - B1b allele. The starch composition of wheat grain has a primary influence on flour quality. Wheat starch consists of two types of glucose polymers: amylose (22-35% of the total) and amylopectin (68-75% of the total). Amylose is synthesized by waxy proteins. Several studies have contributed to the catalogue of waxy alleles available for breeders, and the search for novel alleles of these and other proteins related to flour quality continues. In this report, we describe the characterization of two novel Wx-B1 alleles (Wx-B1k and Wx-B1m) in a collection of macha, Indian dwarf and club wheat. Several accessions lacking Wx-B1 protein were detected, and some were caused by the common Wx-B1b null allele. Of the other accessions, four from Indian dwarf wheat showed the insertion of 4 bp within the seventh exon, and one from club wheat had a deletion of four nucleotides in the second exon. These mutations were novel and provisionally catalogued as Wx-B1k and Wx-B1m, respectively, and could be used to enlarge the genetic variability for this gene.

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Identification of a null allele at the Wx‐A1 locus in durum wheat (Triticum turgidum L. ssp. durum Desf.)

Cited by 8 publications

References 17 publications

Wheat waxy proteins: polymorphism, molecular characterization and effects on starch properties

Wheat waxy proteins: polymorphism, molecular characterization and effects on starch properties

Molecular characterization of several Wx alleles in durum wheat

Molecular characterization of waxy alleles in three subspecies of hexaploid wheat and identification of two novel Wx-B1 alleles

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