New gene fights potato blight

If you’re like most people, the biggest potato crisis you ever face is the common lunchtime question: “Do you want fries or chips with that?”

Potato farmers have much bigger worries. A serious disease called blight threatens potatoes all over the world. Millions of people starved when the disease destroyed potato crops in Ireland and elsewhere 150 years ago. Today, farmers spend billions of dollars every year to fight the disease.

The healthy potato plant on the right had an extra gene added to protect it from potato blight whereas the one in the middle did not. The plant on the left wasn’t exposed to blight.

John Helgeson/Univ. of Wisconsin

Now, scientists say they have found a new weapon against blight: a potato that has already solved the problem on its own.

A wild variety of potato called Solanum bulbocastanum is immune to blight. Researchers from Wisconsin and California extracted four carefully chosen genes from a batch of S. bulbocastanum plants. They then spliced one gene into each of four groups of potato plants.

When the researchers exposed all four groups of potatoes to the funguslike organisms that cause blight, one bunch stayed healthy. The scientists think the gene that went into the healthy bunch is critical for blight resistance.

Farmers normally use toxic chemicals to fight blight. Using genetic engineering techniques could be less expensive and kinder to the environment, some researchers say.

Other people are more concerned about transferring genes from one species to another. No one knows how the technology will affect the environment or evolution.

Still, the possibility of keeping potato crops strong and healthy is appealing. Among other things, it would mean a steady supply of french fries for years to come. And, goodness knows, a french fry crisis would be quite hard for many of us to bear.