Characterization of a new bipartite begomovirus infecting bean in northwestern (NW) Argentina

PABLO REYNA; PATRICIA RODRÍGUEZ PARDINA; NICOLAS BEJERMAN; IRMA G LAGUNA

Davis

Simposio; 9th International Geminivirus Symposium & the 7th International ssDNA Comparative Virology Workshop; 2019

UC Davis

Beans provide a highly nutritious food, containing protein, fiber, complex carbohydrates, vitamins, and micronutrients. About 400 million people in the tropics eat beans as part of their daily diet. Farmers struggle to satisfy consumer demand, producing around 12 million tons of common beans every year worldwide. In the world 17 begomovirus species have been identified from naturally infecting beans;while, so far, seven species were identified in Argentina: Bean golden mosaic virus (BGMV), Tomato yellow spot virus (ToYSV), Soybean blistering mosaic virus (SbBMV), Tomato mottle wrinkle virus (ToMoWV), Sida golden mosaic Brazil virus (SiGMBRV), Tomato yellow vein streak virus (ToYVSV) and Euphorbia mosaic virus (EuMV). Nucleic acid hybridization probes specific for these begomoviruses were developed, and used to assay field samples. Some of the analyzed begomovirus-infected samples did not react with any of the specific probes; so we suspected that other begomovirus species were present. DNA of one of these samples, collected in General Mosconi, Salta province, was amplified by rolling circle amplification (RCA), and cloned. The complete genome of a bipartite begomovirus was full-length sequenced. Analysis of the genome organization and phylogenetic comparisons revealed that the virus is a typical New World begomovirus. Nucleotide comparisons established that the two genomic components, DNA-A (2752 nts) and DNA-B (2522 nts), shared 84% and 74% nucleotide identity with Pepper leaf roll virus and Pavonia yellow mosaic virus, respectively. Therefore, following species demarcation criteria of the International Committee on Taxonomy of Viruses, this virus isolate belongs to a new begomovirus specie. Bean plants of Alubia cultivar were infected with the new virus through genegun system. The infected plants developed leaf roll and stunting symptoms, similar to those observed in field-infected plants, therefore, the name bean bushy stunt virus is proposed for this new virus.