Effects of coinfection with East Asian Passiflora virus and East Asian Passiflora distortion virus on Passiflora foetida

Abstract

East Asian Passiflora virus (EAPV) and East Asian Passiflora distortion virus (EAPDV), members of the potyvirus genus, infect passionfruit (Passiflora edulis × P. edulis f. flavicarpa). We found EAPV and EAPDV coinfecting passionfruit in Okinawa Prefecture, Japan and here investigated the effects of coinfection with those viruses on P. foetida, a wild passionfruit. Coinfection with EAPV and EAPDV resulted in different symptoms and viral titers in P. foetida. Mixed inoculation (EAPV + EAPDV) and inoculation with EAPV and 6 days later with EAPDV (EAPV → EAPDV) caused the most severe leaf symptoms at 28 dpi, whereas inoculation with EAPDV then EAPV (EAPDV → EAPV) induced milder symptoms. Single infection with EAPDV caused the mildest symptoms. Quantitative analysis revealed that the log10 of EAPDV titer in EAPDV → EAPV, EAPV → EAPDV, and D + A, was 1.85-, 1.52-, and 1.56-fold higher, respectively, than after a single infection with EAPDV. EAPV titer was always lower than the EAPDV titer. In short, EAPV induced EAPDV propagation, and P. foetida is a potential reservoir for EAPV and EAPDV.