Dr. Whitham and crew discover how Asian soybean rust fungus suppresses plant immunity

October 12, 2016
News

Asian soybean rust, Phakospora pachyrhizi, is a devastating pathogen of soybean crops in warm, humid environments worldwide. The USDA estimates that the fungus can cause up to 80% yield losses, given the right conditions. Though the fungus flourishes in the Southeast United States it has been of little threat here in Iowa thanks to our harsh winters and lack of one of its main alternative hosts, Kudzu

Dr. Steve Whitham, and his team of researchers, recently published their findings in PLOS pathogens on how the fungus interacts with the soybean plant to suppress immunity: "A Small Cysteine-Rich Protein from the Asian Soybean Rust Fungus, Phakopsora pachyrhizi, Suppresses Plant Immunity"

Abstract: The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate biotrophic pathogen causing severe soybean disease epidemics. Molecular mechanisms by which P. pachyrhizi and other rust fungi interact with their host plants are poorly understood. The genomes of all rust fungi encode many small, secreted cysteine-rich proteins (SSCRP). While these proteins are thought to function within the host, their roles are completely unknown. Here, we present the characterization of P. pachyrhizi effector candidate 23 (PpEC23), a SSCRP that we show to suppress plant immunity. Furthermore, we show that PpEC23 interacts with soybean transcription factor GmSPL12l and that soybean plants in which GmSPL12l is silenced have constitutively active immunity, thereby identifying GmSPL12l as a negative regulator of soybean defenses. Collectively, our data present evidence for a virulence function of a rust SSCRP and suggest that PpEC23 is able to suppress soybean immune responses and physically interact with soybean transcription factor GmSPL12l, a negative immune regulator.

ALSO check out ISU News Services' recent article about these findings HERE

Category: