Biology subjects

Burguener, G.

Publications and source records attributed to Burguener, G..

4 recordsLinked to original sources

bioRxiv2026

A genetic toolkit to reduce wheat immunogenicity and incidence of celiac disease

Celiac disease (CeD) is an immune-mediated condition triggered by wheat gluten in genetically predisposed individuals. The immune reaction in people with CeD is driven by particular gluten amino acid sequences, or immunogenic epitopes. Some of these epitopes elicit strong immune responses in the majority of CeD patients and are designated as immunodominant epitopes. Previous research has shown correlations between the amount of immunogenic wheat epitopes consumed and the onset of CeD, suggesting that reducing wheat immunogenic epitopes may reduce CeD incidence at the population level. Gluten consists of gliadins and glutenins, with gliadins having the majority of the immunodominant epitopes and glutenins playing a major role in dough strength and breadmaking quality (BMQ). This study used radiation-induced deletions, chemical mutagenesis, and natural variation in wheat (Triticum aestivum) to generate genetic stocks with reduced immunogenic epitope content. Most lines were developed in the wheat cultivar Summit, for which we produced a full genome assembly and annotation. We used exome capture to characterize these deletions and identify prolamins located within and outside the deletions. We combined different deletions and developed molecular markers to facilitate their deployment. For chromosome arms 1BS and 1DS, we generated two alternative lines: one lacking immunogenic epitopes for the development of CeD-safe genetic stocks for research purposes, and another retaining selected glutenins for breeding commercial lines with reduced immunogenicity and adequate BMQ. By making these non-transgenic genetic stocks publicly available, we aim to accelerate the development of wheat varieties with reduced immunogenicity and, eventually, a fully CeD-safe wheat.

plant biology↗

bioRxiv2025

Spatial and single-cell expression analyses reveal complex expression domains in early wheat spike development

Wheat is important for global food security and understanding the molecular mechanisms driving spike and spikelet development can inform the development of more productive varieties. In this study, we integrated single-molecule fluorescence in situ hybridization (smFISH) and single-cell RNA sequencing (scRNA-seq) to generate an atlas of cell clusters and expression domains during the early stages of wheat spike development. We characterized spatiotemporal expression of 99 genes by smFISH in 48,225 cells at the early transition, late double ridge, and floret primordia stages. These cells were grouped into 21 different expression domains, including four in the basal region of the developing spikelets and three different meristematic regions, which were consistent across spikelets and sections. Using induced mutants, we revealed functional roles associated with the specific expression patterns of LFY in intercalary meristems, SPL14 in inflorescence meristems, and FZP in glume axillae. Complementary scRNA-seq profiling of 26,009 cells from W2.5 and W3.5 stages identified 23 distinct cell clusters. We used the scRNA-seq information to impute the expression of 74,464 genes into the spatially anchored smFISH-labelled cells and generated a public website to visualize them. We used experimental and imputed expression profiles, together with co-expression studies and correlation matrices, to annotate the scRNA-seq clusters. From co-expression analyses, we uncovered genes associated with boundary genes TCP24 and FZP, as well as the meristematic genes AGL6 and ULT1. The smFISH and scRNA-seq studies provided complementary tools for dissecting gene networks that regulate spike development and identifying new co-expressed genes for functional characterization.

plant biology↗

bioRxiv2024

Deletion of wheat alpha-gliadins from chromosome 6D improves gluten strength and reduces immunodominant celiac disease epitopes

Wheat gliadins and glutenins confer valuable end-use characteristics but include amino acid sequences (epitopes) that can elicit celiac disease (CeD) in genetically predisposed individuals. The onset of CeD in these individuals is affected by the amount and duration of the exposure to immunogenic epitopes. Therefore, a reduction of epitopes that result in high immune responses in the majority of CeD patients (immunodominant epitopes) can reduce the incidence of CeD at a population level. We identified deletions encompassing the -gliadins at the three wheat genomes, designated hereafter as{Delta} gli-A2 (PI 704906),{Delta} gli-B2 (PI 704907), and{Delta} gli-D2 (PI 704908). The{Delta} gli-D2 deletion, which eliminates major immunodominant epitopes, significantly increases gluten strength, improves breadmaking quality, and has no negative effects on grain yield or grain protein content. By contrast,{Delta} gli-A2 and{Delta} gli-B2 showed limited effects on breadmaking quality. The stronger effect of the{Delta} gli-D2 deletion on gluten strength is associated with the presence of -gliadins with seven cysteines in GLI-D2 that are absent in GLI-A2 and GLI-B2 loci, which all have -gliadins with six cysteines. We show that -gliadins with seven cysteines are incorporated into the gluten polymer, where they likely function as chain-terminators limiting the expansion of the gluten polymer and reducing its strength. In summary, the publicly available{Delta} gli-D2 deletion developed in this study can be used to simultaneously improve wheat gluten strength and reduce immunodominant CeD epitopes.

plant biology↗

bioRxiv2022

A second generation capture panel for cost-effective sequencing of genome regulatory regions in wheat and relatives

As genome resources for wheat expand at a rapid pace, it is important to update targeted sequencing tools to incorporate improved sequence assemblies and regions of previously unknown significance. Here, we developed an updated regulatory region enrichment capture for wheat (Triticum L.) and other Triticeae species. The core target space includes sequences from two Kbp upstream of each gene predicted in the Chinese Spring wheat genome (IWGSC RefSeq Annotation v1.1) and regions of open chromatin identified with ATAC-seq from wheat leaf and root samples. To improve specificity, we aggressively filtered candidate repetitive sequences using a combination of BLASTN searches to the Triticeae Repetitive Sequence Database (TREP), identification of regions with read over-coverage from previous target enrichment experiments, and k-mer frequency analyses. The final design comprises 216 Mbp of predicted hybridization space in hexaploid wheat and showed increased specificity and coverage of targeted sequences relative to previous protocols. Test captures on hexaploid and tetraploid wheat and other diploid cereals show that the assay has broad potential utility for cost-effective promoter and open chromatin resequencing and general-purpose genotyping of various Triticeae species.

genomics↗