Characterization of a new cytorhabdovirus discovered in papaya (Carica papaya) plantings of Ecuador and its relationship with a bean-infecting strain from Brazil

Abstract

The complete genome of a new rhabdovirus infecting papaya (Carica papaya L.) was sequenced and characterized. The genome consists of 13,469 nucleotides with six canonical open reading frames (ORFs) predicted from the antigenomic strand. In addition, two overlapping short ORFs were predicted between ORFs 3 and 4. Phylogenetic analyses using amino acid sequences from the nucleocapsid, glycoprotein and polymerase, grouped the virus with members of the genus Cytorhabdovirus, with rice stripe mosaic virus, yerba mate chlorosis-associated virus and Colocasia bobone disease-associated virus as closest relatives. The 3 leader and 5 trailer sequences were 144 and 167 nt long, respectively. Each end contains complementary sequences prone to form panhandle structures. The motif 3-AUUCUUUUUG-5, conserved across rhabdoviruses, was identified in all but one intergenic regions; whereas the motif 3-ACAAAAACACA-5 was found in three intergenic junctions. This is the first complete genome of a cytorhabdovirus infecting papaya. The virus was prevalent in commercial plantings of Los Rios, the most important papaya producing province of Ecuador. During the final stage of this manuscript preparation, the genome of a bean-associated cytorhabdovirus became available. Nucleotide identity (97%) between both genomes indicated that the two viruses are strains of the same species, for which we propose the name papaya cytorhabdovirus E.