Communication Infectivity of recombinant strawberry vein banding virus DNA

Infectivity of the cloned DNA genome of strawberry vein banding virus (SVBV) was demonstrated by particle bombardment of 4-week-old strawberry (Fragaria vesca L. var. UC-5) plants with gold particles coated with the putative full-length 7?9 kb viral DNA. Vein banding symptoms developed on 15 % of inoculated plants 6–7 weeks post-inoculation. An approximate 1?25-mer of the viral DNA was cloned into the binary vector pCGN1547. Particle bombardment of this construct into strawberry plants gave an infection rate of 75 %. The construct was used for transformation of Agrobacterium tumefaciens, and infiltration of these cells into healthy strawberry leaves resulted in development of vein banding symptoms in 100 % of inoculated plants. Gel electrophoresis, Southern blot hybridization with an SVBV probe and sequence analyses of PCR-amplified DNA fragments were used to confirm SVBV infection in symptomatic plants. Strawberry vein banding virus (SVBV) has a double-stranded DNA genome (Stenger et al., 1988; Petrzik et al., 1998) of approximately 8 kbp encapsidated in icosahedral particles of approximately 45 nm diameter (Kitajima et al., 1973; Morris et al., 1980). SVBV is transmitted in a semi-persistent manne