Characterization of tomato zonate spot virus, a new tospovirus in China

An isolate of a new tospovirus species, causing concentric zoned ringspots on fruits and necrotic lesions on leaves of infected plants, was characterised based on particle morphology, host range and serological properties. The complete nucleotide sequences of large (L), medium (M), and small (S) RNAs of this virus were found to contain 8919, 4945, and 3279 nts respectively. The L RNA encoded the RNA-dependent RNA polymerase (RdRp) (2885 aa, 332.7 kDa). The M RNA encoded a non-structural (NSm) protein (309 aa, 34.4 kDa) and a viral glycoprotein precursor (Gn/Gc) (1122 aa, 127.4 kDa). The S RNA encoded a non-structural protein (NSs) (459 aa, 51.9 kDa) and the nucleocapsid (N) protein (278 aa, 30.6 kDa). This N protein shared amino acid identities of 80.9% with those of calla lily chlorotic spot virus. Our results suggest that the virus studied here belongs to a new tospovirus species, for which the name tomato zonate spot virus is proposed.