ISU Researchers Sequence Genome of a Soybean Fungus Responsible for Sudden Death Syndrome

AMES, Iowa — Researchers at Iowa State University have generated a draft genome sequence of Fusarium virguliforme, a pathogen that causes sudden death syndrome (SDS) in soybeans.

Using this draft genome sequence, the scientists have identified candidate genes required for causing SDS in soybeans and also the genes unique to this pathogen.

The sequencing was funded by the Iowa Soybean Association and the Soybean Research Development Council. The study and research data are available for researchers through the open-access journal PLOS ONE (…) and an Iowa State internet database.

Madan Bhattacharyya, an associate professor of agronomy leading the research team, said the genome sequence generated for the research community will expedite efforts towards discovering mechanisms this pathogen uses to cause disease, and will ultimately lead to soybeans with improved SDS resistance.

“We’ve just drawn the roadmap so that researchers can do their work in an efficient way. This is a resource for them to avoid doing all the hard experiments that took us more than six months. Now we can do the same work in less than a week,” Bhattacharyya said. “There is so much known about pathogens similar to our SDS pathogen, we can use that information to quickly determine if it is applicable to our pathogen.”

Bhattacharyya says future plans include creating a gene for the development of a soybean resistant to SDS. They also have started to incorporate resistance genes from another plant species into soybean plants for enhancing SDS resistance. And they will explore if soybean can genetically be modified to suppress the growth of the SDS pathogen in infected roots. The work has been funded by a $5.35 million Agriculture and Food Research Initiative (AFRI) grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture (USDA-NIFA) that started in January 2013.

“Our goal has been to produce SDS-resistant soybean plants. Thanks to the funding from USDA-NIFA, and also from Iowa Soybean Association; we have a golden opportunity to accomplish our longer-term goal. We are beginning our second year of the grants from both agencies and already we’ve made a lot of progress,” he said.

“Dr. Bhattacharyya and his colleagues have built an outstanding collaboration that has delivered impressive advances in molecularly characterizing the pathogen that causes SDS,” said Ed Anderson, senior director of supply and production systems at the Iowa Soybean Association. “Because the genetic and biochemical interactions between pathogens and their host plants are complex and constantly evolving, a thorough understanding of the pathogen genome is essential for developing durable defense strategies to protect plants against these disease pathogens.”

Other scientists on the genome sequencing team include Subodh Srivastava, postdoctoral scientist in Bhattacharyya lab and bioinformatician at University of Arkansas, Fayetteville; Xiaoqiu Huang, professor of computer science at Iowa State; Hargeet Brar, manager of molecular biology at ACGT Inc.; Ahmad Fakhoury, associate professor of plant soil and agricultural systems at Southern Illinois University; and Burton Bluhm, assistant professor of plant pathology at the University of Arkansas, Fayetteville.

The Iowa Soybean Association develops policies and programs that help farmers expand profit opportunities while promoting environmentally sensitive production using the soybean checkoff and other resources. The association is made up of 10,000 farmer members and is governed by an elected volunteer board of 21 farmers.