Aphid transmissibility of onion yellow dwarf virus isolates with an N-terminal truncated HC-Pro is aided by leek yellow stripe virus

We recently reported that most of the onion yellow dwarf virus (OYDV) isolates detected from garlic in Hokkaido, Japan have a short HC-Pro. Because HC-Pro has been found to be necessary for aphid transmission, OYDV with a short HC-Pro (OYDV-S) conceivably may have lost aphid transmissibility. We here confirmed that OYDV-S was transmitted by aphids only when coinfecting the host with another potyvirus, leek yellow stripe virus (LYSV); OYDV with an intact HC-Pro was transmitted by aphids without LYSV. We presume that LYSV HC-Pro works in trans as a platform that interlinks both LYSV and OYDV-S with the aphid stylet.

Automated summary

Recent research has shown that most OYDV isolates from garlic in Hokkaido, Japan have a short HC-Pro, possibly resulting in loss of aphid transmissibility. It was confirmed that OYDV-S can only be transmitted by aphids when co-infecting the host with LYSV, while OYDV with intact HC-Pro can be transmitted without LYSV. The study suggests that LYSV HC-Pro acts as a platform linking both LYSV and OYDV-S with the aphid stylet in trans.