Nigerian tobacco latent virus: a new Tobamovirus from tobacco in Nigeria

Field-grown tobacco plants in Nigeria showing chlorotic mottle and marginal veinbanding on the leaves apparently contained several viruses. One of them proved to be a new Tobamovirus for which we suggest the name Nigerian tobacco latent virus (NTLV), because it did not produce systemic symptoms on various cultivars of Nicotiana tabacum. Sequence analyses of the coat and movement protein genes and their translation products, as well as serological studies, revealed that NTLV is only distantly related to known Tobamoviruses from which it also differs in host range and symptomatology. Its closest relationship was found to Tobacco mild green mosaic virus (TMGMV). The percentages of amino acid sequence identity amounted to 73% for the coat proteins and to 64% for the movement proteins of the two viruses. The total sequence of 1415 nucleotides analysed share 63% identity with the corresponding region of TMGMV. In the immunoelectron microscopical decoration test using antisera at a dilution of 1 : 50, reactions of NTLV were observed only with its own antiserum and one out of two antisera to TMGMV. An antiserum to NTLV diluted 1 : 2 failed to react with TMGMV. NTLV induces the formation of characteristic inclusions in infected cells.