Novel plant-associated genomoviruses from the Brazilian Cerrado biome.

The discovery rate of new plant viruses has increased due to studies involving high-throughput sequencing (HTS), particularly for single-stranded DNA viruses of the family Genomoviridae. We carried out an HTS-based survey of genomoviruses in a wide range of native and exotic trees grown in the Brazilian Cerrado biome, and the complete genome sequences of two novel members of the family Genomoviridae from two distinct genera were determined. Specific primers were designed to detect these genomoviruses in individual samples. A new gemykolovirus (Tecoma stans associated gemykolovirus) was detected in Tecoma stans, and a new gemykibivirus (Ouratea duparquetiana associated gemykibivirus) was detected in Ouratea duparquetiana. A gemykrogvirus related to Gila monster associated gemykrogvirus (80% pairwise identity) was also detected in foliar samples of Trembleya parviflora. Our pilot study paves the way for a better characterization of this diverse collection of genomoviruses as well as their interactions with the associated tree species.

Tomato golden net virus and tomato yellow net virus: two novel New World begomoviruses with monopartite genomes.

Two novel tomato-infecting begomoviruses were discovered via high-throughput sequencing in Brazil. Both viruses were also Sanger-sequenced and displayed DNA-A components phylogenetically related to New World bipartite begomoviruses. The names tomato golden net virus (ToGNV) and tomato yellow net virus (ToYNV) were proposed. The majority of the New World begomoviruses has bipartite genomes. However, extensive analyses revealed that ToGNV and ToYNV have monopartite genomes, because no cognate DNA-B components were detected. Hence, they may comprise a unique group of monopartite New World begomoviruses, which have enormous biological, molecular, and plant breeding interest.