Page 287 - PC2019 Program & Proceedings

PLANT CANADA 2019

P147. Development of a Grapevine rupestris stem pitting-associated virus strain Syrah clone and
expression/VIGS vectors for Vitis vinifera
Roscow, O.; B. Meng
University of Guelph

Grapevines are an economically significant crop in Canada and there is increasing concern regarding the
impact of pathogens on quality and health, particularly regarding viral pathogens. Grapevine rupestris
stem pitting associated virus strain Syrah (GRSPaV-SY) is a single-stranded, positive-sense RNA virus of
the genus Foveavirus in the family Betaflexiviridae that has been suggested to be a contributing factor to
the Rugose Stem Pitting, Syrah Decline, and Grapevine Vein Necrosis diseases. Infection with multiple
viruses makes it difficult to attribute symptoms and diseases to a specific virus, delaying development of
treatment strategies for these diseases, as well as research on the fundamental biology of grapevine
viruses. Full-length infectious clones (FLC) of viruses can be used to investigate disease associations and
molecular biology by replicating singular infections and coinfections in grapevines. It is also difficult to
study functional genomics and protein expression in woody plants like grapevines, which may be aided
by more efficient virus-induced gene silencing (VIGS) and GFP expression vectors, respectively. The
hypotheses are that GRSPaV-SY is one of the factors contributing to RWC, SD, and/or GVN and that a
GRSPaV-SY-based viral vector can be used to develop GFP-tagged and/or VIGS vectors for Nicotiana
benthamiana and Vitis vinifera.

Olivia Roscow (oroscow@uoguelph.ca)

P148. Molecular characterization of plasmodesmata-located protein Osmotin34 from Arabidopsis
and its association with Turnip Mosaic Virus Infection
2
*1
3
He, R. ; M. Bernards ; A. Wang
2
1 Western University; The University of Western Ontario;
3 Agriculture and Agri-Food Canada; University of Western Ontario
Plasmodesmata (PD) are plasmamembrane-lined pores that traverse the cell walls to
establish cytoplasmic and endomembrane continuity between neighboring cells. As intercellular
channels, PD controls the movement of protein complexes including plant viruses. Viral cell-to-cell
movement via PD requires the coordinated action of virus-encoded proteins and host factors, especially
PD-localized ones. To better understand the involvement of PD in viral infection, our lab conducted a
quantitative proteomic study on the PD-enriched fraction from Nicotiana benthamiana leaves in response
to turnip mosaic virus (TuMV) infection. Osmotin was identified to be significantly differentially
accumulated in TuMV-infected leaves, when compared to its level in the corresponding healthy control.
To characterize the possible role of osmotin in TuMV infection, we chose osmotin34 (OSM34), an
ortholog from Arabidopsis thaliana (AtOSM34) for further study. Subcellular localization assay in N.
benthamiana leaves reveals that AtOSM34 is indeed localized to PD. In Arabidopsis, AtOSM34
expression is upregulated by TuMV infection, which is consistent with the previous quantitative
proteomic data derived from N. benthamiana. Overexpression of AtOSM34 promotes TuMV replication
and intercellular movement. Confocal microscopy revealed that AtOSM34 is recruited to the viral
replication complex (VRC) of TuMV. Protein-protein interaction assay revealed that AtOSM34 interacts
with the TuMV viral protein VPg, a key component of the VRC. These data suggest that AtOSM34 may
play an important role in TuMV infection.

Rongrong He (rhe46@uwo.ca)

Page 285 of 339