Lisianthus enation leaf curl virus, a newly invaded begomovirus into Japan, is more virulent than the prevalent tomato yellow leaf curl virus in Ty-gene-mediated resistant tomato cultivars

Abstract In 2020, tomato plants showing yellow leaf curl disease (TYLCD) were tested for begomovirus infection in Okinawa prefecture, Japan. Amplification and sequence analysis of circular DNA in the diseased samples showed that, some of the tomato plants carrying a Ty-3a resistance gene to tomato yellow leaf curl virus (TYLCV) were co-infected with TYLCV and lisianthus enation leaf curl virus (LELCV). LELCV infection was also detected in pepper plants in Okinawa by PCR-based diagnosis, suggesting that the virus is widespread in the region. To characterize the interactions of LELCV, TYLCV-IL and TYLCV-Mld with tomato cultivars that carry different Ty resistance genes, we conducted agroinoculation of the viruses. The resistance conferred by Ty-2 was effective against TYLCV-IL but not effective against TYLCV-Mld and LELCV. In contrast, Ty-3a conferred resistance was effective against TYLCV strains but not fully effective against LELCV. Furthermore, mixed infection of TYLCV-IL and LELCV in tomato plants bearing Ty-3a induced even more significant TYLCD symptoms and growth inhibition than did LELCV singly infected plants. Our study demonstrated that the newly invaded LELCV is a more virulent begomovirus species than the prevalent TYLCV isolates in resistant tomato cultivars.