Australia, the world’s No. 2 supplier of wheat, could struggle to soak up extra demand if international buyers increasingly shun the U.S. grain after an unapproved genetically modified strain of the crop was found in Oregon. Major buyers Japan and South Korea have shelved plans to purchase U.S. wheat, while other Asian nations say they are monitoring the situation as U.S. officials race to quell alarm following news of the discovery. But tightening supply from Australia in the wake of unsustainably brisk exports and growing demand from domestic livestock farmers could drive buyers elsewhere, with Canadian and European sellers set to profit.