Molecular characterization of a subgroup I geminivirus from a legume in South Africa

A South African geminivirus, proposed name bean yellow dwarf virus (BeYDV), was isolated from <i>Phaseolus vulgaris</i> cv. Bonus displaying stunting, chlorosis and leaf curl symptoms. A full-length cloned copy of the viral genome produced characteristic symptoms of the disease when reintroduced into <i>P. vulgaris</i> by agroinoculation, and was systemically infectious in <i>Nicotiana benthamiana</i>, <i>N. tabacum</i>, <i>Lycopersicon esculentum</i>, <i>Datura stramonium</i> and <i>Arabidopsis thaliana</i>. BeYDV resembles subgroup I geminiviruses which infect monocotyledonous plants in possessing a single DNA component, 2 non-overlapping virion-sense (V1 and V2) and 2 overlapping complementary-sense (C1 and C2) coding regions, and an intron within the complementary-sense coding regions that is excised to produce a C1C2 fusion protein. It is most closely related to tobacco yellow dwarf monogeminivirus from Australia, the only subgroup I geminivirus previously known to infect dicotyledonous plants, although it is sufficiently dissimilar (65% nucleotide sequence identity) to be considered distinct