Opportunities for manipulating the seed protein composition of wheat and barley in order to improve quality

Shewry, Peter R.; Tatham, Arthur S.; Halford, Nigel G.; Barker, Jackie H. A.; Hannappel, Ulrich; Gallois, Patrick; Thomas, Mark S.; Kreis, Martin E.

doi:10.1007/bf01976021

Cited by 32 publications

(17 citation statements)

References 39 publications

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“…Comparisons of different harvesting time points evidently showed strong changes in expression of these genes and, on the other hand, slight differences in expression of these genes for material harvested at the same time point indicated asynchronous development of the plant material. The expression levels over time of the phytase gene, driven by the 1DX5 HMW glutenin promoter, appeared to parallel that of the HMW glutenins, as previously well-documented for this promoter (Shewry et al, 1994). Also the bar gene was properly identified in the transgenic line although with expression levels considerably lower than for the phytase gene.…”

Section: Discussionmentioning

confidence: 58%

A Microarray-Based Comparative Analysis of Gene Expression Profiles During Grain Development in Transgenic and Wild Type Wheat

Gregersen¹,

Brinch-Pedersen²,

Holm³

2005

Transgenic Res

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Global, comparative gene expression analysis is potentially a very powerful tool in the safety assessment of transgenic plants since it allows for the detection of differences in gene expression patterns between a transgenic line and the mother variety. In the present study, we compared the gene expression profile in developing seeds of wild type wheat and wheat transformed for endosperm-specific expression of an Aspergillus fumigatus phytase. High-level expression of the phytase gene was ensured by codon modification towards the prevalent codon usage of wheat genes and by using the wheat 1DX5HMW glutenin promoter for driving transgene expression. A 9K wheat unigene cDNA microarray was produced from cDNA libraries prepared mainly from developing wheat seed. The arrays were hybridised to flourescently labelled cDNA prepared from developing seeds of the transgenic wheat line and the mother variety, Bobwhite, at three developmental stages. Comparisons and statistical analyses of the gene expression profiles of the transgenic line vs. that of the mother line revealed only slight differences at the three developmental stages. In the few cases where differential expression was indicated by the statistical analysis it was primarily genes that were strongly expressed over a shorter interval of seed development such as genes encoding storage proteins. Accordingly, we interpret these differences in gene expression levels to result from minor asynchrony in seed development between the transgenic line and the mother line. In support of this, real time PCR validation of results from selected genes at the late developmental stage could not confirm differential expression of these genes. We conclude that the expression of the codon-modified A. fumigatus phytase gene in the wheat seed had no significant effects on the overall gene expression patterns in the developing seed.

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Section: Discussionmentioning

confidence: 58%

A Microarray-Based Comparative Analysis of Gene Expression Profiles During Grain Development in Transgenic and Wild Type Wheat

Gregersen¹,

Brinch-Pedersen²,

Holm³

2005

Transgenic Res

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“…However, in the present study, we could not identify an advantageous haplotype or SNP sites in the investigated candidate genes comparable to the ones found in the sh4 -d gene in rice, the Q-gene in wheat and the ppd-H1 gene in barley [49-51]. As the present candidate genes were described as trans -active regulators for hordein encoding genes [11,12,14,52], we hypothesize that they influence both grain protein composition and protein content and thus are of importance not only for malting [53] but also for nutritional quality [54]. …”

Section: Discussionmentioning

confidence: 97%

DNA polymorphisms and haplotype patterns of transcription factors involved in barley endosperm development are associated with key agronomic traits

et al. 2010

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BackgroundAssociation mapping is receiving considerable attention in plant genetics for its potential to fine map quantitative trait loci (QTL), validate candidate genes, and identify alleles of interest. In the present study association mapping in barley (Hordeum vulgare L.) is investigated by associating DNA polymorphisms with variation in grain quality traits, plant height, and flowering time to gain further understanding of gene functions involved in the control of these traits. We focused on the four loci BLZ1, BLZ2, BPBF and HvGAMYB that play a role in the regulation of B-hordein expression, the major fraction of the barley storage protein. The association was tested in a collection of 224 spring barley accessions using a two-stage mixed model approach.ResultsWithin the sequenced fragments of four candidate genes we observed different levels of nucleotide diversity. The effect of selection on the candidate genes was tested by Tajima's D which revealed significant values for BLZ1, BLZ2, and BPBF in the subset of two-rowed barleys. Pair-wise LD estimates between the detected SNPs within each candidate gene revealed different intra-genic linkage patterns. On the basis of a more extensive examination of genomic regions surrounding the four candidate genes we found a sharp decrease of LD (r2<0.2 within 1 cM) in all but one flanking regions.Significant marker-trait associations between SNP sites within BLZ1 and flowering time, BPBF and crude protein content and BPBF and starch content were detected. Most haplotypes occurred at frequencies <0.05 and therefore were rejected from the association analysis. Based on haplotype information, BPBF was associated to crude protein content and starch content, BLZ2 showed association to thousand-grain weight and BLZ1 was found to be associated with flowering time and plant height.ConclusionsDifferences in nucleotide diversity and LD pattern within the candidate genes BLZ1, BLZ2, BPBF, and HvGAMYB reflect the impact of selection on the nucleotide sequence of the four candidate loci.Despite significant associations, the analysed candidate genes only explained a minor part of the total genetic variation although they are known to be important factors influencing the expression of seed quality traits. Therefore, we assume that grain quality as well as plant height and flowering time are influenced by many factors each contributing a small part to the expression of the phenotype. A genome-wide association analysis could provide a more comprehensive picture of loci involved in the regulation of grain quality, thousand grain weight and the other agronomic traits that were analyzed in this study. However, despite available high-throughput genotyping arrays the marker density along the barely genome is still insufficient to cover all associations in a whole genome scan. Therefore, the candidate gene-based approach will further play an important role in barley association studies.

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“…Over half of the identified proteins are seed storage proteins, vicilin, convicilin, legumin, a lectin and albumin 2. Albumin 2 shows limited sequence similarity to the superfamily of seed proteins that includes protease inhibitors, amylase inhibitors and a diverse range of other low-molecular-weight albumins [10]. It is not obvious how the presence of the bean a-AI would have altered the post-translational modification of some of these and reduced the expression of others but it is noteworthy that these storage proteins, in common with a-AI, are processed through the endoplasmic reticulum and Golgi before being deposited in storage vacuoles [11].…”

Section: Discussionmentioning

confidence: 99%

Transgenic peas expressing an α‐amylase inhibitor gene from beans show altered expression and modification of endogenous proteins

et al. 2009

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Differential in-gel electrophoresis showed contrasting effects of the transgenic expression of an alpha-amylase inhibitor from beans on the proteomes of two pea cultivars. One cultivar showed minor changes relative to its non-transgenic parent with only one protein changing by more than about twofold. Changes in the abundance of certain endogenous proteins in the other cultivar were of greater number and magnitude with some endogenous proteins undetected while some new protein spots appeared in the transgenic proteome. The sets of proteins with altered expression were generally different between the two cultivars. Some of the proteins that were differentially expressed were identified by MS. Most were seed storage globulins, which are sited together with the transgenic product. Some of the changes may be due to alterations in expression levels but there were also changes due to post-translational processing.

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Opportunities for manipulating the seed protein composition of wheat and barley in order to improve quality

Cited by 32 publications

References 39 publications

A Microarray-Based Comparative Analysis of Gene Expression Profiles During Grain Development in Transgenic and Wild Type Wheat

A Microarray-Based Comparative Analysis of Gene Expression Profiles During Grain Development in Transgenic and Wild Type Wheat

DNA polymorphisms and haplotype patterns of transcription factors involved in barley endosperm development are associated with key agronomic traits

Transgenic peas expressing an α‐amylase inhibitor gene from beans show altered expression and modification of endogenous proteins

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