Poster: Biology & Disease Mgmt: Virology
Identification of conserved sequences within tospovirus genomes for broad-spectrum resistance using RNA interference (RNAi)
J. OLIVER (1), D. Rotenberg (1), A. Whitfield (1) (1) Kansas State University, U.S.A.
Tomato spotted wilt virus (TSWV) and other tospoviruses cause significant yield losses in numerous crop species worldwide. Genetic resistance is the most effective management tool for tospovirus diseases in tomato; however, resistance breaking isolates of TSWV have emerged which are capable of overcoming the currently deployed resistance genes. An alternative to traditional resistance genes is transgenic resistance through the process of RNA interference (RNAi). Though effective against tospoviruses, the sequence-specific nature of RNAi means that resistance can break down if host plants are challenged with genetically diverse populations of tospoviruses. To examine viral sequence diversity, we used publically available viral sequences of TSWV and other tospoviruses. Our approach focused on identifying short, highly conserved regions among 2679 TSWV sequences and across 589 additional sequences from seven tospovirus species. This analysis allowed us to locate sequence conservation within each of the five tospovirus genes. The identified sequences corresponded to motifs of known biological importance. Based upon their high conservation at the nucleotide level, correspondence with known biological functions, and low potential for off-target effects in tomato, these sequences have been incorporated into anti-viral RNAi constructs for tomato transformation.