This study describes the nucleotide sequence and characterization of Sida golden mosaic virus (SiGMV-Co), a new bipartite geminivirus isolated from the common weed Sida rhombifolia in Costa Rica. The virus has two genomic components: DNA A (2605 nucleotides) encoding five proteins including coat protein and replication factors, and DNA B (2587 nucleotides) encoding two proteins involved in viral spread and symptom development. Sequence analysis revealed that SiGMV-Co is most closely related to bean dwarf mosaic virus (BDMV) and other New World geminiviruses, clustering separately from African cassava mosaic virus. The researchers created infectious clones and tested them by agroinoculation in seven plant species, including tomato and bean, all of which became infected. Symptoms included stunting and leaf curling, with some plants showing mosaic patterns. Notably, S. rhombifolia initially showed severe symptoms that partially recovered after four weeks. The findings suggest that infected Sida plants may serve as natural reservoirs for geminiviruses that threaten economically important crops in Central America.

Key findings

• SiGMV-Co is a new bipartite geminivirus with DNA A (2605 nt) and DNA B (2587 nt) components, most closely related to bean dwarf mosaic virus
• The virus successfully infected multiple plant species including tomato, bean, tobacco, and datura via agroinoculation
• S. rhombifolia serves as a natural host for the virus and may function as a reservoir for crop infection in Central America
• Phylogenetic analysis shows SiGMV-Co clusters with New World geminiviruses rather than African species like ACMV