Biology subjects

Stoddard, F. L.

Publications and source records attributed to Stoddard, F. L..

4 recordsLinked to original sources

bioRxiv2026

VC1 and the production of vicine and convicine in the genus Vicia

Many Vicia species contain vicine and convicine (VC), which limit the use of faba bean and some vetches in food and feed. The first step in VC biosynthesis in V. faba is shared with the riboflavin pathway and attributed to VC1, a member of the ribAB family. Since riboflavin is ubiquitous to life, we examined the distribution of VC production in genus Vicia. Three accessions of each of 33 Vicia species were grown in glasshouse conditions to provide fresh seeds for VC analysis and leaves for DNA analysis. PCR was used to amplify fragments of the VC1/ribAB gene for sequencing, and these sequences were used to create a phylogenetic tree. COX1 and ITS2 sequences were used for examining the nucleotide diversity in the subgenera. VC and DNA sequences consistent with VC1 were found only in members of subgenus Vicia. In V. lathyroides, VC1 was present but no VC was detected. There was less sequence diversity in VC1/ribAB sequences of subgenus Cracca than in those of subgenus Vicia, suggesting that ribAB remained under stricter purifying selection than VC1. VC1 is confirmed as a prerequisite for the presence of VC, and the gene and its products are restricted to subgenus Vicia. HighlightThe favism-causing factors of vetches and faba bean, vicine and convicine, depend on the presence of the VC1 variant of the ribAB gene, which is found in only one subgenus.

plant biology↗

bioRxiv2021

Genomic regions associated with chocolate spot (Botrytis fabae Sard.) resistance in fababean (Vicia faba L.)

Chocolate spot (CS), caused by Botrytis fabae Sard., is an important threat to global faba bean production. Growing resistant faba bean cultivars is, therefore, paramount to preventing yield loss. To date, there have been no reported quantitative trait loci (QTLs) associated with CS resistance in faba bean. The objective of this study was to identify genomic regions associated with CS resistance using a recombinant inbred line (RIL) population derived from resistant accession ILB 938. A total of 165 RILs from the cross Melodie/2 x ILB 938/2 were genotyped and evaluated for CS reactions under replicated controlled climate conditions. QTL analysis identified five loci contributing to CS resistance on faba bean chromosomes 1 and 6, accounting for 5.0-23.4% of the total phenotypic variance. The sequences of SNP markers linked to resistance QTLs on chromosome 1 that have the largest effects encode multiple classes of putative disease and/or defense-related genes. The results of this study not only provide insight into disease-resistance QTLs, but also can be used as potential targets for marker-assisted breeding in faba bean genetic improvement for CS resistance. Key messageQTL mapping identified key genomic regions associated with chocolate spot resistance on faba bean chromosomes 1 and 6, which may serve as novel genetic tools to develop disease-resistant faba bean cultivars.

genomics↗

bioRxiv2020

VC1 catalyzes a key step in the biosynthesis of vicine from GTP in faba bean

Faba bean is a widely adapted and high-yielding legume cultivated for its protein-rich seeds1. However, the seeds accumulate the anti-nutritional pyrimidine glucosides vicine and convicine, which can cause haemolytic anaemia--favism--in the 400 million individuals genetically predisposed by a deficiency in glucose-6-phosphate dehydrogenase2. Here, we identify the first enzyme associated with vicine and convicine biosynthesis, which we name VC1. We show that VC1 co-locates with the major QTL for vicine and convicine content and that the expression of VC1 correlates highly with vicine content across tissues. We also show that low-vicine varieties express a version of VC1 carrying a small, frame-shift insertion, and that overexpression of wild-type VC1 leads to an increase in vicine levels. VC1 encodes a functional GTP cyclohydrolase II, an enzyme normally involved in riboflavin biosynthesis from the purine GTP. Through feeding studies, we demonstrate that GTP is a precursor of vicine both in faba bean and in the distantly related plant bitter gourd. Our results reveal an unexpected biosynthetic origin for vicine and convicine and pave the way for the development of faba bean cultivars that are free from these anti-nutrients, providing a safe and sustainable source of dietary protein.

biochemistry↗

bioRxiv2019

Evaluation of yield, yield stability and yield-protein trade-off in commercial faba bean cultivars

Faba bean is a legume crop with high protein content and large potential for cultivation in the Northern latitudes. However, it has a reputation for being an unstable crop with large inter-annual variability, mostly explained by yearly variation in rainfall. Consequently, the objective is to breed cultivars with high seed yield and high yield stability. In this study, 17 commercial cultivars of faba bean were evaluated for seed yield, yield stability and trade-off between seed yield and protein content in four locations in Denmark and Finland during 2016-2018. We found that location and year effects accounted for 72% of the total seed yield variation. Cultivar by environment interactions (GxE) were found to be small and did not cause re-ranking of cultivars in different environments. Yield stability contributed little to the mean yield of the cultivars because high-yielding cultivars consistently outperformed the lower yielding genotypes, even under the most adverse conditions. The latter was also the case for total protein yield quantified as total yield multiplied by seed protein percentage. Although we found a strong negative correlation of -0.64 between yield and protein content, a few cultivars produced high yields while maintaining a relatively high protein content, suggesting that these traits may to some degree be genetically separable.

plant biology↗