Wheat is the most widely cultivated crop on Earth, and makes up about a fifth of the total calories consumed by humans. Despite its importance in nutrition and agriculture, until recently, scientists were in the dark about the genetic makeup of one of our most staple foods. Now, after 13 years of work, the International Wheat Genome Sequencing Consortium (IWGSC) has published the first complete and accurate map of the wheat genome.
Bread wheat has a large and complex genome with 16 billion DNA base pairs – more than five times larger than the human genome. But it’s not just its size that makes the wheat genome challenging to sequence. Bread wheat is also a hybrid of three different wheat species and contains three sub-genomes, with long repeated sections of DNA nested within each other, making it difficult to distinguish each section and put the genome in order.
“It’s a billion-piece jigsaw puzzle with 90% blue sky and 10% clouds,” study co-author Andrew Sharpe from the University of Saskatchewan told CBC News. “You can imagine putting together a jigsaw puzzle of essentially the same thing.”
The consortium, made up of 202 researchers across 20 countries including researchers from University of Saskatchewan, Agriculture and Agri-Food Canada and Canada’s National Research Council, was working chromosome by chromosome, a slow and tedious process.
But recent advances in gene mapping technology and genetic analysis have greatly sped up this process. Having sequenced other plant genome, Sharpe and co-author Curtis Pozniak, also of the University of Saskatchewan, applied this new technology to the wheat genome through a genome mapping company called NRGene using next-generation sequencing and big data genomic algorithms. This, coupled with in-depth analysis by members of the IWGSC, allowed the team to develop a framework sequence for the entire genome of a wheat variety called Chinese Spring within three months.
This new understanding could help researchers accelerate innovation and breed resilient, disease resistant-crops with higher yields and enhanced nutritional quality. It will also help scientists predict how well new varieties of wheat will perform in drought, high humidity or other inhospitable climates before the seed is even in the ground.
These are important considerations as agricultural regions around the planet adapt to climate change, and ramp up production to meet anticipated global demand of 60% more wheat by 2050.
Published in Science, this research is supported by a second paper, co-authored by researchers from the University of Toronto, University of Saskatchewan, Agriculture and Agri-Food Canada and Canada’s National Research Council, that provides annotation and resources to support researchers and breeders in understanding how wheat genes affect traits.