Plant Resistance Gene May Cause Susceptibility Too

Plants get sick too, but they have special genes that provide resistance to plant diseases. A plant gene that confer resistance to one disease, however, may also produce susceptibility to a different disease, as botanists at the Oregon State University found out. Using Arabidopsis thaliana engineered with the Pc-2 gene, they reexamined the case of the 1940s epidemic of  Victoria blight, a fungal disease in oats. At that time, an imported variety of oats that contains the Pc-2 gene was widely-planted because of its resistance to oat rust, another costly crop disease, but it proved to be susceptible to Victoria blight. As a rsult, Its use had to be discontinued. 

“The blight fungus makes a toxin that causes disease in susceptible plants – that is, only plants that carry the Pc-2 gene,” said Jennifer Lorang, an OSU research associate. “But it also turned out that the same gene can provide disease protection. This is very unusual, and should provide insight into genetic influences on disease resistance and susceptibility.”

The complete article is available at http://oregonstate.edu/dept/ncs/newsarch/2007/Aug07/geneticresistence.html.