Currently, roughly 20 percent of humanity’s caloric intake comes from wheat. Agricultural strains, specialized for bread or pasta production, have been bred for high productivity and resistance to many agricultural pests. But over the past few years, one of those pests, a fungus called wheat stem rust, has evolved the ability to overcome wheat’s defenses. Dangerous strains of wheat stem rust were first spotted in Uganda, but are now present elsewhere in Africa, in Yemen, and in some areas of Iran. That’s set off an international scramble to find ways of generating a resistant wheat before the rust spreads any further.
By working with uncultivated relatives of agricultural wheat, two teams of scientists have identified a pair of genes, each of which provides partial resistance to the new strain of stem rust. Although each gene can be bred back into commercial wheat strains, the combination of the two is likely to be even more potent, so the researchers are considering putting them on a single DNA construct and then engineering that into various agricultural strains.