Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 2003
Publication Date: January 10, 2004
Citation: BARGABUS, R.L., WEILAND, J.J. APPLICATION OF RNA SILENCING FOR THE CONTROL OF BENYVIRUSES OF SUGARBEET. PLANT AND ANIMAL GENOME XII ABSTRACTS. 2004. Abstr. No. W257. p. 69. Technical Abstract: Beet necrotic yellow vein virus (BNYVV), a multipartite single-stranded RNA benyvirus causing Rhizomania disease in sugarbeet, is a serious threat worldwide. Resistant sugarbeet varieties currently available succumb to Rhizomania under severe disease pressure, prompting the investigation into novel means of preventing infection. RNA silencing, a naturally occurring phenomenon, results in the post-transcriptional degradation of aberrant double-stranded RNAs, including mRNAs, preventing protein synthesis. This process has been induced under laboratory conditions for preventing virus infections in numerous plant and animal host-virus systems and may operate in currently deployed transgenic plants exhibiting virus resistance. Guide sequences used for eliciting RNA silencing were designed to target RNA1 of BNYVV (and the related beet soilborne mosaic virus) that encodes genes for viral replication. Sequence blocks from the untranslated and coding regions of the RNA dependent RNA polymerase gene on RNA1 were amplified by reverse transcriptase (RT)-PCR. Silencing constructs were developed by cloning the RT-PCR generated fragments in a head-to-head orientation that aids in assembly of double-stranded hairpin RNAs. Similar hairpin RNA constructs were produced by direct synthesis of deoxyoligonucleotides of 120 bases in length (60 base hairpin 'arms'). Delivery of the constructs into beet plants will be attempted using Agrobacterium tumefaciens and barley stripe mosaic virus as vectors, both capable of infecting sugarbeet. Non-BNYVV coding constructs derived from beet curly top virus will serve as experimental controls. Preliminary results describing the efficacy of the two delivery systems and the double stranded RNAs used as guide sequences will be discussed.