When you pick up the perfect apple in the supermarket it’s easy to forget that plants get sick just like we do. A more realistic view might come from a walk outside during summer: try to find a leaf without a speck, spot or blemish. Tough, huh? Those are the signs of a microscopic battle waged every day in and on plants.
Just like us, plants are covered in microbes. And just like us, plants have evolved an immune system to protect against the dangerous ones. But our current agricultural system works against plants’ natural immune defenses, by limiting the tools plants have to fight back and restricting evolution of new tools.
Pesticides provide us with most of the spotless produce in the grocery store. Even so, many apples still don’t make it to market. About a third end up as juice or applesauce, because they don’t meet the beauty standards of the American consumer. Forget about blemishes – Panama Disease threatens nearly all of the world’s banana production, and the only effective treatment is toxic to the soil.
Scientists studying plant immunity are figuring out how to fight plant diseases without chemical pesticides. Some researchers plan to give our crops vaccines, just like the shots we administer to ourselves to fend off the flu or smallpox. My lab seeks to identify ways plants defend themselves in the wild. With that information, we can use modern breeding techniques and genetic engineering to strengthen the immunity of our crops and gardens.
Over the last 25 years, advances in genetics and molecular biology have revealed new secrets of plant immunity.