 This was done by inserting a specific gene from wheat, oxalate oxidase, into the American chestnut genome.The enzyme oxalate oxidase is an extremely common fungal defense in plants, and is found in strawberries, bananas, oats, barley, and other cereals.Oxalate oxidase breaks down the oxalic acid which the fungus secretes in the cambium to lower the pH and subsequently kill plant tissues.