ARS | Publication request: Soybean root defense responses to Fusarium virguliforme infection reveals a role of defense related genes during resistance

Submitted to: American Phytopathology Society
Publication Type: Abstract Only
Publication Acceptance Date: June 16, 2009
Publication Date: August 1, 2009
Repository URL: http://meeting.apsnet.org/overview/default.cfm
Citation: Radwan, O., Clough, S.J. 2009. Soybean root defense responses to Fusarium virguliforme infection reveals a role of defense related genes during resistance [abstract]. American Phytopathology Society. 99:S106.

Technical Abstract: Sudden death syndrome of soybean is an important disease, caused by the semi-biotrophic fungus Fusarium virguliforme. This fungus colonizes soybean roots causing rot, and releases a phytotoxin that is translocated to leaves causing interveinal chlorosis and possible defoliation. In this study, we report on an Affymetrix analysis measuring transcript abundances in resistant (PI 567374) and susceptible (Williams 82) roots upon infection by F. virguliforme. Real-time RT-PCR was used to measure fungus infection progress and to determine that the ideal time points for analysis were 5 and 7 days post infection. Analysis of root response to F. virguliforme infection versus mock inoculated plants, identified 1279 transcripts as being differentially expressed at an fdr adjusted p-value of <0.01. Many of up regulated genes were common between resistant and susceptible plants, including genes related to the phenylpropanoid pathway, defense, signal transduction, and transcription factors. Some of the genes uniquely expressed in the resistant plant included those encoding putative heat shock protein 22, an R-protein, and transcription factors MYB101 and WRKY21. Gene expression comparisons between this experiment and another that was designed to study the effect of translocated phytotoxin on soybean leaves, indicated that most of the genes showed similar expression patterns in both leaves and roots, suggesting that many defense responses are shared between these two very different tissues upon F. virguliforme infection. The transcript levels of many induced genes were induced to a greater degree in the susceptible plants probably as a result of the more rapid colonization of the susceptible plants.