Insight into the code of healthy grain

The surprisingly extensive and mosaic-like structure of the oat genome reflects the interesting properties of the grain. © Olof Olsson

The tricky genome of the “trend cereal” oats has now been cracked: Researchers have sequenced the genome of the plant and have already gained insights into the basics of the health and ecological advantages that oats offer compared to wheat and the like. Among other things, it is confirmed that it is suitable for the diet of people with gluten intolerance. The genetic information can now also be used to further improve the ancient crop through breeding, say the scientists.

For a long time it was overshadowed by other types of grain – but then interesting peculiarities gave oats a new career: Studies show that the consumption of this type of grain has a beneficial effect on the metabolism, and it also triggers fewer allergies and intolerances. At the same time, oats also offer ecological advantages: the cultivation requires comparatively little plant protection and fertilization. The grain also offers potential for reducing the carbon footprint as it can provide a substitute for an animal product: vegan oat milk is enjoying increasing popularity.

Against the background of these interesting aspects, grain has also increasingly become the focus of genome research. But until now there has been a gap: in contrast to other types of grain, the oats did not have a complete genome sequence. The reason: “The trend grain is genetically very complicated,” explains Manuel Spannagl from Helmholtz Zentrum München. Above all, the genome is amazingly extensive: while humans only have two sets of chromosomes with around 20,000 genes, the oat genome has six sets of chromosomes with a total of more than 80,000 genes. In addition, these genes are arranged in a comparatively confusing manner – oats have a distinctly mosaic-like genome architecture. Nevertheless, Spannagel and his international colleagues have now mastered the challenge: they succeeded in decoding the entire oat genome.

On the trail of positive health aspects

By analyzing and comparing the gene sequences, the scientists have already been able to gain insights into the basics of certain characteristics of oats. They were particularly interested in why it triggers fewer allergies and intolerances than wheat or rye. They have now been able to show at the genetic level that oats produce hardly any substances that correspond to gluten in wheat. These proteins are considered the basis of the so-called celiac disease and wheat intolerance. “The results of this study show that genes encoding potential gluten-like substances are rare, low-expressed and less likely to lead to the production of inflammatory substances,” explains co-author Jason Tye-Din from Edith Cowan University. Co-author Nadia Kamal from the Helmholtz Zentrum München says: “We were thus able to confirm at the genomic level that oats in their pure form are suitable for a gluten-free diet”.

The genetic information also shows that oats form far more so-called beta-glucans than other types of grain. This is dietary fiber that can contribute to low blood cholesterol and also has a beneficial effect on metabolic diseases such as type 2 diabetes. Thanks to the sequencing, the scientists can now show which genes are responsible for these health-promoting beta-glucans in oats.

basis for further breeding

The researchers say that the genomic information can now also be used to breed oats to further increase their health and agro-environmental benefits. “Because we now understand better which oat varieties are compatible with each other. This allows us to combine traits for an even better health profile, higher yields, better resistance to pests and drought, and most importantly, in preparation for climate change,” says Nick Sirijovski from Lund University. According to the researchers, oats also have further potential, as they can also deliver good yields with modest soil quality and have a smaller overall ecological footprint than wheat, for example.

“In summary, it can be said that this fully annotated hexaploid oat reference genome forms the basis for advances in oat breeding and basic oat biology,” says co-author Martin Mascher from the Leibniz Institute of Plant Genetics and Crop Plant Research in Leipzig. “Modern breeding strategies such as genome editing and gene pyramiding can now be more easily applied to oats in order to develop varieties that meet the increasing global demand for oat products,” says the scientist.

Source: Helmholtz Zentrum München German Research Center for Environmental Health, Leibniz Institute for Plant Genetics and Crop Plant Research, Edith Cowan University, specialist article: Nature, doi: 10.1038/s41586-022-04732-y

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