In a paper titled "A Soybean Cyst Nematode Resistance Gene Points to a New Mechanism of Plant Resistance to Pathogens," scientists reveal that they identified and validated the gene at the Rhg4 locus, a major driver in a soybean plant's resistance to SCN.
"The checkoff has a number of projects that aim to identify the genes in a soybean plant that can effectively control SCN," says USB Production program Chair Jim Schriver, a soybean farmer from Bluffton, Ind. "Even though there are different types of SCN, if we could take advantage of those genes that control resistance, it would be effective for all types of SCN."
The study, published recently in the online journal Nature, is the first to identify the gene and its mechanism for creating resistance, according to the article's lead authors, Khalid Meksem, Ph.D., of Southern Illinois University Carbondale (SIUC) and Melissa Goellner Mitchum, Ph.D., of the University of Missouri at Columbia.
"Funding and support from USB and the soy checkoff have been crucial to this new discovery of disease resistance, which will be used to develop products that will benefit U.S. soybean farmers," says Meksem, associate professor of plant, soil science and agricultural systems at SIUC. "This discovery comes at a time when farmers need new solutions, as the nematodes adapt and find ways through the soybeans' defenses."
The team hopes their research will lead to a better understanding of how the resistant genes work and ultimately lead to improved crop yield.
A separate checkoff-funded project recently found that soybean plants with multiple copies of a multi-gene block known as Rhg1 also show better resistance to SCN. Both projects allow researchers to focus on these gene structures – Rhg1 and Rhg4 – to help them develop SCN-resistant U.S. soybean varieties.