Researchers discover structural differences between two viruses that infect sweet potatoes

A team of researchers led by Juan José López Moya has published a study that characterizes the structural properties of two viruses that infect sweet potatoes, one of the most important staple crops and a good model organism to study multiple viral infections in plants.

The two viruses belong to two genera, Potyvirus and Ipomovirus, within the Potyviridae family but are transmitted by aphids and whiteflies, respectively. These insects are acting as vectors of their transmission from plant to plant, but little is known about what makes these two viruses from the same family have so different and highly specific vectors.

To analyse these differences, scientists used a technique called CryoEM to obtain high-resolution images of the viral particles, focusing in Virus-like particles (VLPs) that were generated in a model plant (Nicotiana benthamiana) and purified in large quantities to perform the structural and stability analysis. The results of the study showed that the two viruses share a common helical arrangement of their coat proteins into flexuous rods but have different structural properties and especially significative different stabilities, which could explain their different specificities for their vectors.

This study can help to better understand how these viruses spread and how their negative effects on plants can be prevented. The findings could also have implications in the fight against many other viral insect-transmitted diseases that affect crops which are also important for human consumption.

Reference article: Chase, O., Javed, A., Byrne, M.J. et al. CryoEM and stability analysis of virus-like particles of potyvirus and ipomovirus infecting a common host. Commun Biol 6, 433 (2023). https://doi.org/10.1038/s42003-023-04799-x

About the authors and funding of the study

This work was conducted with the collaboration of the Horticultural and Bio-imaging platforms at JIC, the Plant Growth core facility at CRAG, and the Servei de Microscòpia UAB whose support were invaluable throughout this study. Funding provided by grant PID2019-105692RB-100 (to J.J.L.M.) and CEX2019-000902-S (awarded to CRAG), both from Agencia Estatal de Investigación AEI, Spain, MCIN/AEI/10.13039/501100011033, by CERCA Programme / Generalitat de Catalunya grant 2018 FI_B 00329 and EMBO Short-Term Fellowship 8695 (to O.C.), by EC Horizon 2020 project Pharma-Factory 774078, and UK Biotechnology and Biological Sciences Research Council (BBSRC) Grants BB/R001669/1 and BB/T004703/1 (to G.P.L.), and BB/T004525/1 (to N.A.R. and G.P.L.), and by Institute Strategic Programme Grant “Molecules from Nature—Enhanced Research Capacity” BBS/E/J/000PR9794 and the John Innes Foundation.

Image: SPFMV and SPMMV structures by CryoEM.