THE COMPLETE NUCLEOTIDE-SEQUENCE OF THE S-RNA OF A NEW TOSPOVIRUS SPECIES, REPRESENTING SEROGROUP-IV

A tospovirus isolate Tospo-To, recently shown to be serologically related to some Taiwanese, Japanese, and Indian tospovirus isolates, was purified and its S RNA segment was cloned and sequenced. The complete nucleotide sequence of the S RNA, 3,536 nucleotides, contained inverted terminal repeats and two large open reading frames in ambisense orientation, separated by an intergenic region that is significantly larger than those of hitherto known tospoviruses. Amino acid sequence comparisons revealed 16 and 33% identities with the Ns(s) and N protein of tomato spotted wilt tospovirus for the viral sense and virus-complementary reading frames, respectively. In contrast to other tospoviruses, additional putative open reading frames besides those for N and Ns(s) have been detected in the nucleic acid sequence of this new tospovirus isolate. The sequence comparisons for N protein amino acid sequences of several different tospovirus species and isolates indicated Tospo-To should be regarded as a new species in the genus Tospovirus as has already been suggested from serological data.