Abstract
Banana streak OL virus (BSOLV) is the primary species of banana streak virus (BSV) affecting banana production in South China. Reverse genetics is a powerful method for studying viral pathogenicity and the interactions between viruses and their hosts; however, no infectious clone of BSOLV has been reported until now. In this study, the BSOLV genome was amplified in overlapping segments to assemble 1.3 times full-length sequence. The resulting construct was then cloned into the yeast-Escherichia. Coli-Agrobacterium shuttle vector pCB301 via yeast homologous recombination, yielding the infectious clone BSOLV-GZ. The complete genome of the cloned BSOLV isolate was 7, 410 bp and shares 99.81% nucleotide sequence identity with the BSOLV isolate 3-S36. The BSOLV-GZ infectious clone was introduced into Brazilian banana seedlings through Agrobacterium-mediated injection. At 30 days post-inoculation (dpi), BSOLV was detected in 19 out of 30 inoculated banana plants by RT-PCR. By 42 dpi, distinct chlorotic streaks appeared in 12 of the 19 RT-PCR-positive plants. This was confirmed by immunocapture PCR (IC-PCR) and Southern blot. Additionally, rod-shaped viruses were observed under transmission electron microscopy in the symptomatic Brazilian banana plants. These findings indicated that the banana plants inoculated with the BSOLV-GZ infectious clone exhibited typical symptoms of infection. The host range of the BSOLV-GZ infectious clone was assessed through Agrobacterium-mediated infiltration; however, none of the tested plants was detected positive by RT-PCR. This research provides a foundational basis for future studies on the activation of endogenous BSOLV and the interactions between the virus and its hosts.