In vivo trans-specific gene silencing in fungal cells by in planta expression of a double-stranded RNA

<p>Abstract</p> <p>Background</p> <p>Self-complementary RNA transcripts form a double-stranded RNA (dsRNA) that triggers a sequence-specific mRNA degradation, in a process known as RNA interference (RNAi), leading to gene silencing. In vascular plants, RNAi molecules trafficking occur between cells and systemically throughout the plant. RNAi signals can spread systemically throughout a plant, even across graft junctions from transgenic to non-transgenic stocks. There is also a great interest in applying RNAi to pathogenic fungi. Specific inhibition of gene expression by RNAi has been shown to be suitable for a multitude of phytopathogenic filamentous fungi. However, double-stranded (ds)RNA/small interfering (si)RNA silencing effect has not been observed <it>in vivo</it>.</p> <p>Results</p> <p>This study demonstrates for the first time the <it>in vivo </it>interference phenomenon in the pathogenic fungus <it>Fusarium verticillioides</it>, in which expression of an individual fungal transgene was specifically abolished by inoculating mycelial cells in transgenic tobacco plants engineered to express siRNAs from a dsRNA corresponding to the particular transgene.</p> <p>Conclusion</p> <p>The results provide a powerful tool for further studies on molecular plant-microbe and symbiotic interactions. From a biotechnological perspective, silencing of fungal genes by generating siRNAs in the host provides a novel strategy for the development of broad fungi-resistance strategies in plants and other organisms.</p