The genome sequence of a gene in wheat responsible for resisting the devastating Wheat Yellow Mosaic Virus (WYMV) has been discovered by a team of scientists from the University of Melbourne, providing vital clues for managing more resistant crops and maintaining a healthy food supply.

The demand for wheat varieties that can resist WYMV is high as wheat crops across the Americas, Asia, Europe, and Africa are frequently ravaged by the disease. WYMV reduces grain yield by up to 80 percent, causing significant economic losses. The study, published in PNAS, found that the resistance gene came from an ancient Mediterranean wild plant relative of wheat.
Researchers have known for a while that a dominant gene called Ym2 reduces the impact of WYMV on wheat plants by 70 percent, but did not understand how the gene achieved this. The research team used positional cloning to locate the Ym2 gene on a chromosome in bread wheat and found that its DNA sequence codes for a protein of the type known as NBS-LRR. These proteins are â??guardians' that detect pathogens and trigger an immune response in plants.
Study lead researcher Dr. Mohammad Pourkheirandish said, â??Now that we know the gene's DNA sequence, we can select breeding lines carrying Ym2." He added that the discovery could assist in the development of more resistant wheat cultivars, increase crop yields, and reduce the use of harmful fungicides.
Wheatâ??s ancient roots of viral resistance uncovered (unimelb.edu.au)