A betasatellite-dependent begomovirus infects ornamental rose: characterization of begomovirus infecting rose in Pakistan.

The Begomovirus genus of the family Geminiviridae comprises the largest group of geminiviruses. The list of begomoviruses is continuously increasing as a result of improvement in the methods for identification. Ornamental rose plants (Rosa chinensis) with highly stunted growth and leaf curling were found in Faisalabad, Pakistan. Plants were analyzed for begomovirus infection, through rolling circle amplification and PCR methods. Based on complete genome sequence homologies with other begomoviruses, a new begomovirus species infecting the rose plants was discovered. In this paper, we propose a new species name, Rose leaf curl virus (RoLCuV), for the virus. RoLCuV showed close identity (83 %) with Tomato leaf curl Pakistan virus, while associated betasatellite showed 96 % identity with Digera arvensis yellow vein betasatellite (DiAYVB), justifying a new isolate for the betasatellite. Recombination analysis of newly identified begomovirus revealed it as a recombinant of tomato leaf curl Pakistan virus from its coat protein region. The infectious molecules for virus/satellite were prepared and inoculated through Agrobacterium tumefaciens to N. benthamiana plants. RoLCuV alone was unable to induce any level of symptoms on N. benthamiana plants, but co-inoculation with cognate betasatellite produced infection symptoms. Further investigation to understand the trans-replication ability of betasatellites revealed their flexibility to interact with Rose leaf curl virus.