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Poster: Biology & Disease Mgmt: Virology


A full genome cDNA clone of Cherry rusty mottle associated virus induces disease in sweet cherry
D. VILLAMOR (1), S. Pillai (1), K. Eastwell (1) (1) Washington State University, U.S.A.

Cherry rusty mottle-associated virus (CRMaV), a member of the family Betaflexiviridae, is associated with cherry rusty mottle disease (CRMD). To date, fulfillment of Koch’s postulates for this virus has yet to be demonstrated. A full genome of CRMaV isolate 98CI194 was cloned into a modified pORE-E4 Agrobacterium binary vector between the ENTCUP2 promoter and the Nos-t terminator. Leaf agroinfiltration with the binary vector carrying ENTCUP2-CRMaV failed to infect Nicotiana benthamiana, N. occidentalis 37B, and N. glutinosa whereas agro-inoculation using either the bark flap technique or root dipping resulted in the induction of CRMD symptoms in Krymsk 6 virus-tested cherry rootstock. Further confirmation of infection was verified by RT-PCR detection of CRMaV amplicon and by positive reaction of symptomatic leaves in ELISA and Western blotting using an antibody against the coat protein of CRMaV 98CI194. Finally, bark patch inoculation using lignified wood from one of the CRMaV positive, agroinoculated, Krymsk 6 trees resulted in CRMD symptoms on virus-tested sweet cherry seedling rootstock Prunus avium ‘Mazzard’. These results provide conclusive evidence of the etiology of CRMD to be caused by CRMaV. This infectious clone provides a tool for future studies of genome expression and pathogenesis of CRMaV. Moreover, the construction of this infectious clone opens a path forward to pursue etiological studies of other stone fruit virus-like diseases.