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TECHNICAL SESSION: Soilborne pathogen interactions

Development of a full-length clone of sugar beet cyst nematode virus 1 and its successful introduction into soybean cyst nematode
Thanuja Thekke Veetil - Department of Crop Sciences, University of Illinois. Leslie Domier- USDA ARS, M. R. Hajimorad- University of Tennessee, Kris Lambert- University of Illinois

Sugar beet cyst nematode (SBCN; Heterodera schachtii) and soybean cyst nematode (SCN; H. glycines) are major pests of sugar beet and soybean, respectively. Sugar beet cyst nematode virus 1 (SBCNV1) is a single-stranded RNA virus recently discovered from eggs and second-stage juveniles (J2) of SBCN that may have the potential to reduce crop losses caused by the two species of nematodes. To establish a reverse-genetic system for SBCNV1, a full-length cDNA copy of the virus genome was amplified from SBCN total RNA using virus-specific primers that added a T7 RNA polymerase promoter and a long poly(A) tail to the 5’ and 3’ termini, respectively, and cloned into a modified pBR322 vector. The SBCNV1 genome was in vitro transcribed from the linearized recombinant plasmid in the presence of cap analog, precipitated onto gold particles, and bombarded into SCN J2 using a PDS-1000/He gene gun. Three weeks post inoculation, SBCNV1 infections were detected in mature SCN males using TaqMan qRT-PCR and nested RT-PCR virus-specific assays. These preliminary results indicate the successful inoculation of SCN with SBCNV1 and the infectivity of SBCNV1 in SCN cells. To our knowledge, this may represent the first reverse-genetic system developed for a virus infecting a plant parasitic nematode, and the first biolistic inoculation of nematodes with nucleic acids of a single-stranded RNA virus.