I read in a Swedish newspaper advertisement some years ago that genetic intervention had been used to knock out part of the plant immunity defence. This advertisement was paid for by starch producer Lyckeby. The potato's own gene repair introduced variation in the resulting repaired genes, giving the plants a broader defense against various possible threats. What is the background to this story?
The reason given for why common agricultural potato varieties have low variation in their defence genes was genetic bottlenecking post-domestication (other potato strains in the endemic range retain substantial diversity).