Investigation of the Possible Host-Induced Silencing in Fusarium virguliforme that Causes Sudden Death Syndrome in Soybean

Inherent RNA silencing mechanisms can be exploited to down-regulate genes by post-transcriptional gene silencing in plants.  The biosynthesis of dsRNA induces production of small interfering RNA (siRNA) molecules that degrade corresponding mRNAs or prevent translation.  More importantly, siRNAs can be generated in transgenic plants to inhibit growth of invading pathogenic organisms by silencing vital pathogen housekeeping genes. This novel siRNA-based mechanism, trans-specific or host-induced gene silencing, enhances disease resistance in plants. We are investigating if such a mechanism can be generated to enhance resistance against Fusarium virguliforme that causes sudden death syndrome (SDS) in soybean. We are in the process of generating a F. virguliforme line carrying the reporter gene GUS.  To interfere with the GUS expression in this to be developed transgenic F. virguliforme line, we have created GUS-specific siRNA molecules in a transgenic soybean plant through Bean pod mottle virus (BPMV)-induced gene silencing of GUS.  We will present data if GUS-specific siRNAs from transgenic soybean plants are able to down regulate the GUS activity in the transgenic F. virguliforme isolate.