Applied and Environmental Microbiology (2016) 82, 6294-6302

N. Killiny, S.J. Harper, S. Alfaress, C. El Mohtar and W.O. Dawson (2016)
Minor coat and heat shock proteins are involved in the binding of Citrus tristeza virus to the foregut of its aphid vector, Toxoptera citricida
Applied and Environmental Microbiology 82 (21), 6294-6302
Abstract: Vector transmission is a critical stage in the viral life cycle, yet for most plant viruses how they interact with their vector is unknown or is explained by analogy with previously described relatives. Here we examined the mechanism underlying the transmission of citrus tristeza virus (CTV) by its aphid vector, Toxoptera citricida, with the objective of identifying what virus-encoded proteins it uses to interact with the vector. Using fluorescently labeled virions, we demonstrated that CTV binds specifically to the lining of the cibarium of the aphid. Through in vitro competitive binding assays between fluorescent virions and free viral proteins, we determined that the minor coat protein is involved in vector interaction. We also found that the presence of two heat shock-like proteins, p61 and p65, reduces virion binding in vitro. Additionally, treating the dissected mouthparts with proteases did not affect the binding of CTV virions. In contrast, chitinase treatment reduced CTV binding to the foregut. Finally, competition with glucose, N-acetyl-β-d-glucosamine, chitobiose, and chitotriose reduced the binding. These findings together suggest that CTV binds to the sugar moieties of the cuticular surface of the aphid cibarium, and the binding involves the concerted activity of three virus-encoded proteins.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Nabil Killiny, Scott J. Harper

Research topic(s) for pests/diseases/weeds:
transmission/dispersal of plant diseases

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis citricidus
	Citrus tristeza virus