Apple Latent Spherical Virus Vector as Vaccine for the Prevention and Treatment of Mosaic Diseases in Pea, Broad Bean, and Eustoma Plants by Bean Yellow Mosaic Virus

We investigated the protective effects of a viral vector based on an Apple latent spherical virus (ALSV) harboring a segment of the Bean yellow mosaic virus (BYMV) genome against mosaic diseases in pea, broad bean, and eustoma plants caused by BYMV infection. In pea plants pre-inoculated with the ALSV vaccine and challenge inoculated with BYMV expressing green fluorescence protein, BYMV multiplication occurred in inoculated leaves, but was markedly inhibited in the upper leaves. No mosaic symptoms due to BYMV infection were observed in the challenged plants pre-inoculated with the ALSV vaccine. Simultaneous inoculation with the ALSV vaccine and BYMV also prevented mosaic symptoms in broad bean and eustoma plants, and BYMV accumulation was strongly inhibited in the upper leaves of plants treated with the ALSV vaccine. Pea and eustoma plants were pre-inoculated with BYMV followed by inoculation with the ALSV vaccine to investigate the curative effects of the ALSV vaccine. In both plant species, recovery from mosaic symptoms was observed in upper leaves and BYMV accumulation was inhibited in leaves developing post-ALSV vaccination. These results show that ALSV vaccination not only prevents mosaic diseases in pea, broad bean, and eustoma, but that it is also effective in curing these diseases.