bioRxiv Science⌕ Search

Biology subjects

Hegarty, J.

Publications and source records attributed to Hegarty, J..

4 recordsLinked to original sources

Manipulation of the microRNA172 - AP2L2 interaction provides precise control of wheat and triticale plant height

The REDUCED HEIGHT (RHT) dwarfing alleles Rht-B1b and Rht-D1b were essential in the "Green Revolution" to optimize wheat plant height and increase grain yield. However, those alleles reduce coleoptile length limiting sowing depth, which triggered the search for alternative dwarfing genes. In this study, we engineered the interaction between miR172 and AP2L2 genes to fine-tune wheat and triticale plant height without affecting coleoptile and first-leaf length.

plant biology↗

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↗

A wheat/rye polymorphism affects seminal root length and is associated with drought and waterlogging tolerance

The introgression of a small segment of wheat chromosome 1BS in the distal region of the rye 1RS arm translocation in wheat (henceforth 1RSrw) was previously associated with reduced grain yield, carbon isotope discrimination and stomatal conductance, suggesting reduced access to soil moisture. In this study, we show that the 1RS/1RSRW polymorphism causes differences in root length in field and hydroponic experiments. In the latter, differences in seminal root length were associated with a developmentally regulated arrest of the root apical meristem (RAM). Approximately 10 days after germination, the seminal roots of the 1RSRW plants showed a gradual reduction in elongation rate and stopped growing a week later. Seventeen days after germination, the roots of the 1RSRW plants showed altered gradients of reactive oxygen species and emergence of lateral roots close to the RAM, suggesting a loss of apical dominance. The 1RS/1RSRW isogenic lines also differed in plant biomass and grain yield under normal, terminal drought, and waterlogging field conditions. The differences were larger in fields with reduced or excessive irrigation. These results suggest that this polymorphism may be useful to modulate root architecture and mitigate the negative impacts of excess or reduced water in wheat production.\n\nHIGHLIGHTA wheat/rye polymorphism in chromosome one affects seminal root length and apical dominance and is associated with differences in drought and waterlogging tolerance in the field.

plant biology↗

Pisces: An Accurate and Versatile Variant Caller for Somatic and Germline Next-Generation Sequencing Data

MotivationNext-Generation Sequencing (NGS) technology is transitioning quickly from research labs to clinical settings. The diagnosis and treatment selection for many acquired and autosomal conditions necessitate a method for accurately detecting somatic and germline variants, suitable for the clinic.\n\nResultsWe have developed Pisces, a rapid, versatile and accurate small variant calling suite designed for somatic and germline amplicon sequencing applications. Pisces accuracy is achieved by four distinct modules, the Pisces Read Stitcher, Pisces Variant Caller, the Pisces Variant Quality Recalibrator, and the Pisces Variant Phaser. Each module incorporates a number of novel algorithmic strategies aimed at reducing noise or increasing the likelihood of detecting a true variant.\n\nAvailabilityPisces is distributed under an open source license and can be downloaded from https://github.com/Illumina/Pisces. Pisces is available on the BaseSpace SequenceHub as part of the TruSeq Amplicon workflow and the Illumina Ampliseq Workflow. Pisces is distributed on Illumina sequencing platforms such as the MiSeq, and is included in the Praxis Extended RAS Panel test which was recently approved by the FDA for the detection of multiple RAS gene mutations.\n\nContactpisces@illumina.com\n\nSupplementary informationSupplementary data are available online.

bioinformatics↗