Crop Biotech Update

Scientists Find Soybean Rust-Resistance Gene

March 27, 2009

A team of researchers from the US Agricultural Research Service (ARS), Iowa State University and the Brazilian Agricultural Research Corporation (EMBRAPA) have pinpointed a group of soybean genes that provides resistance to Phakopsora pachyrhizi, the fungus that causes the Asian soybean rust (ASR). Found in more than 20 states in the US, ASR seriously threatens the country's USD 27 billion soybean crop.

Five loci have previously been associated with ASR resistance. The ARS and Iowa State team focused on a particular locus, Rpp4, where they identified Rpp4C4. Virus-induced gene silencing was used to confirm the role of Rpp4C4 in fending off Phakopsora. The resistance gene could be transferred to high yielding commercial soybean varieties through conventional breeding or biotechnological means.

"Although fungicide use is effective against ASR, providing farmers with resistant cultivars is more sustainable," said Michelle Graham, ARS scientist and leader of the study.

For more information, read The open access paper published by Plant Physiology is available at