News ArticlesStudy pinpoints triple-gene resistance to SCN
October 18 - Scientists have identified three genes that make soybeans resistant to the most damaging disease of soybean: soybean cyst nematodes.
According to an article on the AgProfessional web site, the genes exist side-by-side on a stretch of chromosome, but only give resistance when that stretch is duplicated several times in the plant.
Senior study author Andrew Bent, a professor of plant pathology at University of Wisconsin-Madison, is quoted in the article as saying that nematodes are resilient, able to live for years in the soil. To kill it, you require highly toxic and persistent chemicals.
The preferred strategy at present is to plant varieties that contain a genetic structure called Rhg1. But until now scientists knew few details about how Rhg1 works.
Bent’s study, published in the journal Science, shows that Rhg1 actually houses three genes that work together to confer resistance. A single copy of Rhg1 does not make the plant resistant; they need 10 copies of this three-gene structure to grow well in a field infected with the nematode.
Bent says “having several genes right next to each other that all control the same trait is really common in microbes and fungi, but it's very uncommon in multicellular higher organisms.”
Researchers still don’t know exactly how the three genes fight the nematode only that they are the key to helping soybean plants ward off attack.