Tomato mottle Taino virus pseudorecombines with PYMV but not with ToMoV: implications for the delimitation of cis- and trans-acting replication specificity determinants.

Over the last decade, the tomato production in Cuba has been affected by new whitefly-associated diseases. In addition to the well-documented presence of Tomato yellow leaf curl virus (TYLCV) along the island, the occurrence of bipartite begomoviruses has also been reported. One of them, tentatively named Tomato mottle Taino virus (ToMoTV), has now been cloned and characterized at the molecular level. Its genomic organization is similar to other bipartite geminiviruses. Phylogenetic analyses placed ToMoTV in a subcluster with other geminiviruses isolated in the Caribbean Basin: Tomato mottle virus (ToMoV), Bean dwarf mosaic virus, Abutilon mosaic virus, Sida golden mosaic virus and Potato yellow mosaic virus (PYMV). Biolistic inoculation of tobacco and tomato plants with cloned viral DNA showed that ToMoTV pseudorecombines with PYMV-GP as predicted by the identity of their iterative elements, whereas it does not show the same ability with ToMoV, even when their replication-associated proteins (Rep and REn) show the highest percentage of similarity. A comparative analysis of Rep proteins from begomoviruses that are able to produce viable reassortants suggests that some key elements for virus replication specificity are located in the first ten amino acids of this protein.