Protoplast fusion is another technique used to transfer disease resistance in crop plant. Plant protoplasts can be produced by gently dissolving away the cellulose cell walls using cellulose and pectinase enzyme under carefully controlled iso-osmotic condition with aseptic technique. Protoplasts can then be fused together to from heterokarons. Scientists have used this technique to transfer resistance to three major virus diseases from a naturally resistant wild variety of potato into commercial, high-yielding potato plant. Plant tissue culture technique can then be used to grow new plant from heterokaryons.