Humans have been cultivating durum wheat (Triticum durum) for thousands of years. Along with common wheat (Triticum aestivum) it is the most economically significant variety. Durum wheat is used not only to make bulgur and couscous, but also Italian pasta products. Modern varieties of the wheat are derived from wild emmer (Triticum dicoccoides) as the result of domestication and selective breeding. While the human genome contains around 20,000 genes, researchers have found three times that number in durum wheat – to be precise, 66,559 genes. Eighty percent of the genome sequence is composed of repetitive sequences, also known as repeats.
“Our analysis of the Svevo variety shows how breeding has altered the genome,” says Prof. Klaus Mayer, head of the Plant Genome and Systems Biology (PGSB) Department, Helmholtz Zentrum München. “Comparisons with the wild emmer genome sequence, which was published in 2017**, show the areas in which differences exist.” The team found several regions, some of them overlapping, which had been altered by human intervention. These areas are distributed across the entire genome.
However, the scientists discovered that breeding also resulted in undesirable characteristics being selected: if the soil contains cadmium, the heavy metal accumulates in modern durum wheat but not in wild emmer. “This is due to a gene referred to as TdHMA3-B1, which in durum wheat – in contrast to emmer – no longer has a function,” explains Dr. Manuel Spannagl, group leader in the Plant Genome and Systems Biology (PGSB) group at Helmholtz Zentrum München. TdHMA3-B1 codes for a protein that functions as a metal transporter. It eliminates cadmium from emmer but not from durum wheat. “This demonstrates the contribution that genome research is making to modern crop breeding,” says Dr. Spannagl, noting that possible research aims would be to reduce the cadmium burden through selective breeding as well as to generate varieties that are more resistant to heat and drought.
*The project was coordinated by the CREA Research Centre for Cereal and Industrial Crops, Foggia, Italy; the National Research Council – Institute of Agricultural Biology and Biotechnology, Milan, Italy; the Crop Development Centre and Department of Plant Sciences, University of Saskatchewan, Canada; and by the Department of Plant Genome and Systems Biology (PGSB), Helmholtz Zentrum München.
Department of Communications, Helmholtz Zentrum München – German Research Center for Environmental Health (GmbH), Ingolstädter Landstr. 1, 85764 Neuherberg – Tel. +49 89 3187 2238 – Email: firstname.lastname@example.org
As the German Research Center for Environmental Health, Helmholtz Zentrum München pursues the goal of developing personalized medical approaches for the prevention and therapy of major common diseases such as diabetes mellitus, allergies and lung diseases. To this end, it investigates the interaction of genetics, environmental factors and lifestyle. Helmholtz Zentrum München has about 2,300 staff members and is headquartered in Neuherberg in the north of Munich. It is a member of the Helmholtz Association, a community of 19 scientific-technical and medical-biological research centers with a total of about 37,000 employees.
The Plant Genome and Systems Biology (PGSG) research unit focuses on the analysis of plant genomes, using bioinformatic techniques. To store and manage the data, we developed a database, PlantsDB, that aims to provide a data and information resource for individual plant species. In addition, PlantsDB provides a platform for integrative and comparative plant genome research.
The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) in Gatersleben is one of the world’s leading international institutions in the field of plant genetics and crop science. Its research program and services contribute materially to conserving, exploring and exploiting crop diversity. Its research goals are driven by the need to ensure an efficient and sustainable supply of food, energy and raw materials, thereby addressing a major global ecological challenge.
contact for scientific information:
Prof. Klaus Mayer, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Department of Plant Genome and Systems Biology, Ingolstädter Landstr. 1, 85764 Neuherberg – Tel. +49 89 3187 3584 – Email: email@example.com
Maccaferri, M et al (2019): Durum wheat genome reveals past domestication signatures and 2 future improvement targets. Nature Genetics. DOI: 10.1038/s41588-019-0381-3