"Viral diversity in passion fruit in Brazil"
Sequencing, novel viruses, mixed infection, Passiflora
Passion fruit is a tropical plant (genus Passiflora, family Passifloraceae) cultivated in different regions of the world. Currently, Brazil is the largest producer of passionfruit, has one of the largest origin and diversity centers of the species and harbors one of the largest Passiflora germplasm banks focusing on the conservation and preservation and in the use of the genetic resources of these plants in genetic improvement programs. Diverse symptoms of viral etiology have been reported in passionfruit in the country. However, these viruses are poorly studied. In previous stages of this work were identified viruses infecting passion fruit that were not yet reported in Brazil. To expand the knowledge about viral diversity in this important crop, this study aimed to investigate virus diversity in Passiflora species in Brazil and to characterize newly identified viruses. For this, several passion fruit trees cultivated in commercial fields were sampled in several regions of the country, as well Passiflora spp. accessions from the Germplasm Bank “Flor da Paixão” situated in Distrito Federal. In this study, we used a combination of several tools and methodologies to characterize the viruses present in these plants, including High-Throughput Sequencing (HTS), bioinformatics tools, RT-PCR, PCR, molecular cloning, RACE (5'/3'-rapid amplification of cDNA ends), Southern Blotting, and Sanger sequencing. Our results revealed several unprecedented viruses (new species and viruses described in other crops) infecting different cultivated and non-cultivated species of passionflower. Cowpea aphid-borne mosaic virus (CABMV, genus Potyvirus, family Potyviridae), lettuce chlorosis virus (LCV, genus Crinivirus, family Bromoviridae), cowpea mild mottle virus (CPMMV, genus Carlavirus, family Betaflexiviridae), bean-associated cytorhabdovirus (BaCV, species Cytorhabdovirus caricae, genus Cytorhabdovirus, family Rhabdoviridae), and curcubit aphid-borne yellow virus (CABYV, genus Polerovirus, family Solemoviridae), and novel candidate species in the family Rhabdoviridae were detected. We identified one virus in the genus Cytorhabdovirus, which was named passiflora cytorhabdovirus (PaCV-BAG3), and two in the genus Alphanucleorhabdovirus named passiflora nucleorhabdovirus 2 (PaNV2-BAG3) and passiflora nucleorhabdovirus 1 (PaNV1-PM1BA). Most viruses were identified in mixed infection with at least one other virus, mainly CABMV, which is the predominant virus affecting passion fruit in Brazil. Our data also revealed that these viruses are not restricted to one region/state. CABYV isolates from passion fruit were also characterized and compared with other isolates, revealing a complex of ten distinct species in the genus Polerovirus. Our results expand the viral diversity of passion fruit in Brazil and worldwide. This information will be valuable to understand the epidemiology of these viruses in the country for the development of control strategies more effective for these viruses, and will serve as support in the genetic improvement programs involving the crop