Biology subjects

Lovegrove, A.

Publications and source records attributed to Lovegrove, A..

4 recordsLinked to original sources

bioRxiv2026

Genetic architecture of soluble arabinoxylan fibre in elite genotypes of bread wheat revealed by genome-wide association analysis

Dietary fibre intake remains below recommended levels, and increasing fibre content of widely consumed white wheat flour (derived from the starchy endosperm) represents a scalable strategy to improve public health. In wheat starchy endosperm, arabinoxylan (AX) is the dominant fibre component, with the water-extractable (WE) fraction being particularly beneficial to health. We assembled an Elite Fibre Panel (EFP) of 384 elite modern wheat genotypes from UK commercial breeding programmes and quantified the content of WE-AX in wholemeal, as a proxy for soluble AX in white flour, across two UK field environments. Wholemeal WE-AX, showed substantial quantitative variation and moderate genotype-by-environment interaction, with a broad-sense heritability of 0.68. Genome-wide association analyses using 6,791 SNPs identified seven loci associated with WE-AX content. The strongest and most stable effects were mapped to major loci on chromosomes 1B and 6B, previously implicated in AX regulation, while additional loci of smaller and sometimes environment-dependent effect were detected on chromosomes 3A, 5B, and 7A. Favourable alleles increased WE-AX content by [~]5-15% and combined additively. LD-defined intervals contained several high-confidence candidate genes involved in cell-wall biosynthesis, remodelling and post-depositional modification, including PER1, a validated regulator of arabinoxylan cross-linking, together with genes encoding a UTP-glucose-1-phosphate uridylyltransferase, trichome birefringence-like proteins and xyloglucan endotransglucosylase/hydrolases. These findings demonstrate that substantial gains in soluble AX can be achieved by pyramiding favourable alleles already segregating within elite germplasm, providing a practical route for breeding wheat with enhanced dietary fibre content and improved nutritional quality. Key messageMultiple additive loci controlling soluble arabinoxylan content were identified in elite wheat germplasm, enabling marker-assisted breeding for increased dietary fibre in white flour.

genomics↗

bioRxiv2026

Wheat mutants lacking Starch Synthase 1 have altered starch composition and cell wall content

Starch Synthase 1 (SS1) participates in the synthesis of amylopectin. To determine its role in hexaploid bread wheat, we selected and combined TILLING mutations for each homoeologue to create two independent SS1-deficient lines. The lines, which have different combinations of ss1 mutations, both lacked SS1 protein. Both lines exhibited mild but significant changes to starch phenotype, including fewer short amylopectin chains, a slight increase in B-type starch granules and a modest increase in amylose content. Lack of SS1 also led to changes in the thermal properties of starch measured by differential scanning calorimetry including reduced enthalpy, and increased gelatinization temperature. Despite the changes to starch properties, the starch contents of the mutant lines compared to wild types were within the normal range, as were grain weight and protein content. However, the concentration of total- and water-extractable arabinoxylan, and MLG, were increased in white flour compared to wild-type controls. HighlightLack of SS1 led to changes in starch molecular structure and thermal behavior. Starch content and grain weight were normal but cell wall polysaccharides in white flour were increased.

plant biology↗

bioRxiv2023

A high soluble-fibre allele in wheat encodes a defective cell wall peroxidase responsible for dimerization of ferulate moieties on arabinoxylan

Increasing dietary fibre (DF) intake is an important target to improve health and an attractive strategy for this is to increase the fibre content of staple foods, particularly white bread which is the staple food in many countries. DF in wheat white flour is derived principally from the endosperm cell wall polysaccharide arabinoxylan (AX) and the water-extractable form of this (WE-AX) accounts for the majority of soluble dietary fibre (SDF), which is believed to confer particular health benefits. We previously identified QTLs for soluble dietary fibre (SDF) on 1B and 6B chromosomes in wheat in biparental populations. Here we show that the 6B high SDF allele encodes a peroxidase protein (PER1-v) with a single missense compared to the more common low SDF form (PER1). Wheat lines with the natural PER1-v allele and with an induced knock-out mutation in PER1 showed similar characteristics of reduced dimerization of ferulate associated with water-extractable WE-AX. Decreased ferulate dimerization is associated with decreased cross-linking of the WE-AX chains and increased solubility of AX. Transiently expressed PER1_RFP fusion driven by native promoter in wheat endosperm was shown to localise to cell walls whereas PER1-v_RFP did not; we therefore propose that PER1-v lacks capacity to dimerise AX ferulate in vivo due to mis-localisation. PER1 is the first peroxidase reported to be responsible for oxidative coupling of ferulate on AX, a key process in all grass cell walls. Understanding its role and the effect of variants on AX properties offers a route to control the properties of wheat DF in the human diet.

plant biology↗

bioRxiv2019

Identification of a major QTL and associated marker for high arabinoxylan fibre in white wheat flour

Dietary fibre (DF) has multiple health benefits, and wheat products are major sources of DF for human health. However, DF is depleted in white flour, which is most widely consumed, compared to wholegrain. The major type of DF in white wheat flour is the cell wall polysaccharide arabinoxylan (AX). Previous studies have identified the Chinese wheat cultivar Yumai 34 as having unusually high contents of AX in both water-soluble and insoluble forms. We have therefore used populations generated from crosses between Yumai 34 and four other wheat cultivars, three with average contents of AX (Ukrainka, Altigo and Claire) and one also having unusually high AX (Valoris), in order to map QTLs for soluble AX (determined as relative viscosity) of aqueous extracts of wholemeal flours) and total AX (determined by enzyme fingerprinting of white flour). A number of QTL were mapped, but most were only detected in one or two crosses. However, all four crosses showed strong QTLs for high RV/total AX on chromosome 1B, with Yumai 34 being the increasing parent, and a KASP marker for the high AX Yumai 34 allele was validated by analysis of high AX lines derived from Yumai 34 but selected by biochemical analysis. A QTL for RV was mapped on chromosome 6B in Yumai 34 x Valoris, with Valoris being the increasing allele, which was consistent with the observation of transgressive segregation for this trait. The data indicate that breeding can be used to develop wheat with high AX fibre in white flour.

genetics↗