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Mechelen, J.R. van; Schuurink, Robert C.; Smits, M.; Graner, Andreas; Douma, A.C.; Sedee, N. J. A.; Schmitt, Nathalie; Valk, B.E.

doi:10.1023/a:1006118003998

Cited by 50 publications

(18 citation statements)

References 28 publications

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“…Two different isoforms, LOX-1 and LOX-2, have been purified and characterised [6]: LOX-1 contributes almost exclusively to the total LOX activity in quiescent grains, whereas LOX-2 activity increases rapidly during germination [7]. Three cDNA sequences encoding the LOX proteins have been isolated from barley grains, and the chromosomal locations of their corresponding genes determined: the LoxA and LoxC clones correspond to the LOX-1 and LOX-2 isoforms, respectively [8], and a third clone, known as LoxB [9], encodes a LOX isoform that has not been identified to date. The LoxA and LoxB loci are tightly linked (1 cM) and map to chromosome 4HS, whereas LoxC maps to the long arm of chromosome 5H [9].…”

Section: Introductionmentioning

confidence: 99%

Insight into durum wheat Lpx-B1: a small gene family coding for the lipoxygenase responsible for carotenoid bleaching in mature grains

et al. 2010

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BackgroundThe yellow colour of pasta products is one of the main criteria used by consumers to assess pasta quality. This character is due to the presence of carotenoid pigments in semolina. During pasta processing, oxidative degradation of carotenoid pigments occurs mainly due to lipoxygenase (LOX). In durum wheat (Triticum durum Desf.), two Lpx-1 genes have been identified on chromosome 4B, Lpx-B1.1 and Lpx-B1.2, and evidences have been reported that the deletion of Lpx-B1.1 is associated with a strong reduction in LOX activity in semolina. In the present study, we characterised the Lpx-B1 gene family identified in a durum wheat germplasm collection and related the distribution and expression of the Lpx-B1 genes and alleles to variations in LOX activity in the mature grains.ResultsIn addition to the already known Lpx-B1.1 and Lpx-B1.2 genes, a new gene was identified, Lpx-B1.3, along with three different Lpx-B1.1 alleles, Lpx-B1.1a, Lpx-B1.1b and the partially deleted Lpx-B1.1c. Screening of the germplasm collection showed that all of the genotypes have one of the three Lpx-B1.1 alleles, associated with either Lpx-B1.2 or Lpx-B1.3, thus showing that in this collection the two genes are alternatives. Therefore, based on Lpx-B1 distribution, three different haplotypes were distinguished: haplotype I, carrying Lpx-B1.3 and the Lpx-B1.1b allele; haplotype II carrying Lpx-B1.2 and the Lpx-B1.1a allele; and haplotype III carrying Lpx-B1.2 and the Lpx-B1.1c allele. Determination of Lpx-B1 transcript abundance and total LOX activity in mature grains revealed differences among these three haplotypes: haplotypes I, II and III showed high, intermediate and low levels, respectively, of functional Lpx-B1 transcripts and enzymatic activity.ConclusionsIn this germplasm collection, the Lpx-B1 gene family accounts for most of the total LOX activity in the mature grains. Information on these Lpx-B1 haplotypes provides significant improvement for prediction of LOX-1 activity levels in mature grains, and will therefore help in breeding programmes aimed at selection of new durum wheat genotypes with higher carotenoid contents in their end products.

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Section: Introductionmentioning

confidence: 99%

Insight into durum wheat Lpx-B1: a small gene family coding for the lipoxygenase responsible for carotenoid bleaching in mature grains

et al. 2010

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“…Segregation analysis revealed that LOX thermostability types in the Steptoe/Morex DHLs were governed by a single locus, located at the same locus as the LOX-1 structural gene of chromosome 4H. It is clear that the factor controlling LOX thermostability types was located at the LoxA locus which corresponds with the LOX-1 structural gene [4]. To understand the diversity in the thermostability of seed lipoxygenase-1 (LOX-1), Hirota et al .…”

Section: Discussionmentioning

confidence: 99%

“…LOX-1 is encoded by LoxA mapped on chromosome 4H, while LOX-2 is encoded by LoxC on chromosome 5H [3]. Expression of a third LOX isoform encoded by LoxB, and similar to that of LOX-2, has been detected only after germination and the causal gene has not been identified [4]. …”

Section: Introductionmentioning

confidence: 99%

Sequence variation and haplotypes of lipoxygenase gene LOX-1 in the Australian barley varieties

Harasymow

Zhang

et al. 2014

BMC Genet

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BackgroundLipoxygenases are a family of enzymes which catalyse the hydroperoxidation of polyunsaturated fatty acids with a cis, cis-1,4-pentadiene to form conjugated hydroperoxydienes. Lipoxygenase-1 (LOX-1) in barley worsens the flavour and foam stability of beer. It has become a major selection criteria for malting quality in the last few years.ResultsLipoxygenase activity was investigated in 41 Australian barley cultivars and advanced breeding lines released since the 1950s; the cultivars differed markedly, ranging from 22.3 to 46.5 U/g. The structural gene and its promoter of lipoxygenase-1 were sequenced from the barley varieties representing different levels of LOX. Based on the analysis of nucleotide and deduced amino acid sequences, two major haplotypes were identified. Barley varieties with lower LOX were classified into three categories based on their pedigrees and sequence variations in the structural gene: (1) barley varieties derived from Canadian varieties with the pre-harvest sprouting susceptible allele, (2) Skiff and Hindmarsh with unique haplotype in the structural gene, and (3) Gairdner and Onslow with an unknown mechanism.ConclusionLipoxygenase activity has been reduced in the malting barley cultivars in the last 60 years although it is only recognized as a malting quality trait recently. There are clear haplotypes of the lipoxygenase structual gene. The polymorphisms detected in the structural gene can be used to design molecular markers for selection of low LOX haplotype. Other mechanisms also existed for controlling lipoxygenase activity. The results suggest that it is possible to develop barley varieties with lower LOX by combination of low LOX-1 haplotype and other trans-regulation factors.

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“…For example, three Lox genes were identified in barley— Lox - 1 ( LoxA ), Lox - 2 ( LoxC ), and Lox - 3 ( LoxB ) (Rouster et al 1997, 1998; van Mechelen et al 1999; van Mechelen et al 1995). In beer production, LOX-1 catalyzes the formation of 9-HPOD while LOX-2 catalyzes the formation of 13-HPOD.…”

Section: Introductionmentioning

confidence: 99%

“…In beer production, LOX-1 catalyzes the formation of 9-HPOD while LOX-2 catalyzes the formation of 13-HPOD. LOX-3 is considered irrelevant to beer quality given its low expression level in barley kernels and unclear product specificity (van Mechelen et al 1999). Collectively, LOX-1 is considered the main contributor to malt LOX activity (Doderer et al 1992; Kuroda et al 2003; Yang and Schwarz 1995).…”

Section: Introductionmentioning

confidence: 99%

Rare allele of HvLox-1 associated with lipoxygenase activity in barley (Hordeum vulgare L.)

et al. 2014

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Key messageIdentification and allele-specific marker development of a functional SNP ofHvLox-1which associated with barley lipoxygenase activity.AbstractImproving the stability of the flavor of beer is one of the main objectives in breeding barley for malting, and lipoxygenase-1 (LOX-1) is a key enzyme controlling this trait. In this study, a modified LOX activity assay was used for null LOX-1 mutant screening. Four barley landraces with no detected level of LOX-1 activity were screened from 1,083 barley germplasm accessions from China. The genomic sequence diversity of the HvLox-1 gene of the four null LOX-1 Chinese landraces was compared with that of a further 76 accessions. A total of 104 nucleotide polymorphisms were found, which contained 83 single-nucleotide polymorphisms (SNPs), 7 multiple-nucleotide polymorphisms, and 14 insertions and deletions. Most notably, we found a rare C/G mutation (SNP-61) in the second intron which led to null LOX-1 activity through an altered splicing acceptor site. In addition, an allele-specific polymerase chain reaction marker was developed for the genotyping of SNP-61, which could be used in breeding programs for barley to be used for malting. The objective was to improve beer quality.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-014-2362-3) contains supplementary material, which is available to authorized users.

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Cited by 50 publications

References 28 publications

Insight into durum wheat Lpx-B1: a small gene family coding for the lipoxygenase responsible for carotenoid bleaching in mature grains

Insight into durum wheat Lpx-B1: a small gene family coding for the lipoxygenase responsible for carotenoid bleaching in mature grains

Sequence variation and haplotypes of lipoxygenase gene LOX-1 in the Australian barley varieties

Rare allele of HvLox-1 associated with lipoxygenase activity in barley (Hordeum vulgare L.)

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