Blooming faba beans. Credit: Fred Stoddard
Although faba beans are a great source of protein, only 5% can eat them. A team of international researchers has now identified the gene that produces convicine and vicine, which can be harmful for these people.
A team of international researchers led by the Universities of Helsinki, Copenhagen, and Luke Natural Resources Institute Finland has identified the gene that produces vicine, and convicine. These are dangerous for these people. The Nature Plants publication reports that the VC1 gene is a key component in the biosynthesis of these compounds.
Faba beansPythagoras, his followers, and the Roman priests of Jupiter avoided them. They were associated with death. We know today that faba beans contain the anti-nutrients convicine and vicine, which can lead to favisma, which is a condition that results from red blood cell damage. Plant compounds called anti-nutrients reduce the body's ability absorb essential nutrients.
The second-highest yielding legume, which includes soybean, bean, chickpea, and chickpea, is also called beans. They have the highest starch-containing legumes' seed protein content and outperform soybean in cooler climates. The faba beans are therefore a great source of protein for helping to facilitate a worldwide switch to a plant-based diet. This is important for significant reductions in carbon emission.
If a person is deficient in an enzyme and eats a lot of uncooked faba bean, the convicine and vicine can cause red blood cells to burst. Favism is a form of hemolytic anemia that has limited the use of faba bean. There are many faba beans with low levels of convicine and vicine, but the gene that causes this trait is not known.
Alan Schulman, one of the project leaders, is the head of a joint Luke-University of Helsinki lab. He says: "It seems like the ancient Greeks or Romans must have known about the occasional serious illness caused faba beans." It was only today that we were able to discover the truth about this risk.
Scientists have now identified the gene that controls vicine-convicine levels. They have also identified the mutation in this gene that causes the decrease in synthesis. All faba bean varieties that have a low vicine/convicine content were derived from one accession in a genebank. Two nucleotides were inserted into the VC1 gene. This insertion causes a disruption in VC1 function. It is the only genetic source of low vicine or convicine content.
The promise of sustainable, protein-rich food everyone can enjoy
This research opens the door to the full description of the biosynthetic pathway for vicine, convicine, and eventually, for breeding, production, and commercial use faba bean varieties completely free of these anti-nutritional chemicals. Leading scientists from Canada, Denmark, Finland, Germany and the UK are part of the team. They already look to the future.
Fred Stoddard, University of Helsinki, is another of the project's leaders. He says, "Faba beans are an ancient crop, but now offer new promise for sustainable, protein-rich food that anyone can eat."
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More information: Emilie Bjrnsdotter et. al., VC1 catalyses a crucial step in the biosynthesis vicine in faba beans, Nature Plants (2021). Information from Nature Plants Emilie Bjrnsdotter et. al., VC1 catalyses a crucial step in the biosynthesis vicine in faba beans, (2021). DOI: 10.1038/s41477-21-00950-w