Molecular characteristics of tomato mosaic virus infecting tomato in Uganda

Abstract

Viral diseases are part of the limiting factors to tomato (Solanum lycopersicum L.) cultivation worldwide, reducing both the quality and quantity of yield. Tomato mosaic virus (ToMV) is one of the damaging viruses of tomato. This paper describes molecular characteristics of the full length genome of ToMV isolated from tomato in Uganda (ToMV-Ug). The genomic, ribonucleic acid (RNA), of this isolate is 6383 nucleotides (nts) in length, encoding four open reading frames (ORFs). Based on the homology with other ToMV strains, the 5’ proximal 130 kilo dalton (kDa) ORF and its read-through product (180 kDa) are expected to encode two proteins required for viral genome replication; while the 30 kDa middle ORF and the 17.5 kDa 3’ proximal ORF are expected to encode the movement protein (MP) and coat protein (CP), respectively. The 5’- and 3’- untranslated regions (UTRs) are 71 and 201 nts, respectively. Comparison with previously published ToMV sequences showed that ToMV-Ug is 99% identical to ToMV strains from Africa (Egypt and Zimbabwe), as well as diverse locations such as China, Australia, Germany and Japan; suggesting high levels of sequence conservation within this virus. This is the first report detailing molecular analysis of a ToMV isolate from Uganda and the Eastern and Central Africa regions.

Keywords: Ribonucleic acid, Solanum lycopersicum, Tobamovirus