1 research outputs found
From a movement-deficient grapevine fanleaf virus to the identification of a new viral determinant of nematode transmission
Grapevine fanleaf virus (GFLV) and arabis mosaic virus (ArMV) are nepoviruses responsible
for grapevine degeneration. They are specifically transmitted from grapevine to grapevine by two
distinct ectoparasitic dagger nematodes of the genus Xiphinema. GFLV and ArMV move from cell to
cell as virions through tubules formed into plasmodesmata by the self-assembly of the viral movement
protein. Five surface-exposed regions in the coat protein called R1 to R5, which differ between the
two viruses, were previously defined and exchanged to test their involvement in virus transmission,
leading to the identification of region R2 as a transmission determinant. Region R4 (amino acids
258 to 264) could not be tested in transmission due to its requirement for plant systemic infection.
Here, we present a fine-tuning mutagenesis of the GFLV coat protein in and around region R4 that
restored the virus movement and allowed its evaluation in transmission. We show that residues
T258, M260, D261, and R301 play a crucial role in virus transmission, thus representing a new viral
determinant of nematode transmission