Abstract
The wild plant Lonicera japonica, commonly found associated with tomato crops in Japan has been found to be infected with tobacco leaf curl virus (TLCV). Several novel species of virus-specific single-and double-stranded DNA (ss and dsDNA) were detected from infected plants showing yellow vein mosaic symptoms. Mung bean nuclease studies revealed the presence of unit-genome length duplexes of closed circular, relaxed circular and linear forms of viral DNA. In addition, a subgenomic DNA was also detected. Geminivirus-specific degenerate primers which anneal within the AC1 ORF (replicase gene) and the AV1 ORF (coat protein gene) amplified a fragment of 1.1 kbp, which was cloned and sequenced. Alignment of this sequence with that of TLCV showed complete homology in the intercistronic region, replicase and coat protein genes, indicating the presence of the same TLCV strain as detected from infected tomato. The geminivirus isolated from the common perennial Eupatorium makinoi from Saga Prefecture, Japan, showed 89.2% sequence homology in the AC1 ORF region with the TLCV strain detected in L. japonica. Infected wild plants therefore possess at least two distinct strains of TLCV which may serve as a natural reservoir for infecting crop species.
