A proteomic approach reveals possible molecular mechanisms and roles for endosymbiotic bacteria in begomovirus transmission by whiteflies

Authors: KLIOT, ADI - Volcani Center (ARO); JOHNSON, RICHARD - University Of Washington; MACCOSS, MICHAEL - University Of Washington; KONTSEDALOV, SVETLANA - Volcani Center (ARO); LEBEDEV, GALINA - Volcani Center (ARO); CZOSNEK, HENRYK - Hebrew University; Heck, Michelle; GHANIM, MURAD - Volcani Center (ARO)

Submitted to: Gigascience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2020
Publication Date: 11/1/2020
Citation: Kliot, A., Johnson, R., Maccoss, M., Kontsedalov, S., Lebedev, G., Czosnek, H., Heck, M.L., Ghanim, M. 2020. A proteomic approach reveals possible molecular mechanisms and roles for endosymbiotic bacteria in begomovirus transmission by whiteflies. Gigascience. 9:1-10. https://doi.org/10.1093/gigascience/giaa124.
DOI: https://doi.org/10.1093/gigascience/giaa124

Interpretive Summary: Plant viruses that are transmitted by whiteflies, tiny sap-sucking insects that infest hundreds of different plant species, are among the most devastating viruses in cultivated crops. One of these viruses is called tomato yellow leaf curl virus (TYLCV). Interestingly, not all whitefly populations are capable of transmitting virus. Some whitefly populations are very efficient virus transmitters and others do not transmit virus at all. This study compared TYLCV transmission efficiency in nine whitefly populations collected from around the Middle East and Europe. The populations were classified as good transmitters or poor transmitters. Using mass spectrometry, a team of ARS scientists and university partners characterized the proteins and bacteria that varied in these different populations. These proteins and bacteria may be useful biomarkers to rapidly identify insect populations in the field that are more likely to transmit virus and allow for a more aggressive and targeted pest management strategy aimed at controlling the most serious vector populations and minimizing the development of insecticide resistance.

Technical Abstract: Many plant viruses are vector-borne and depend on arthropods for transmission between host plants. Begomoviruses, the largest, most damaging and emerging group of plant viruses, infect hundreds of plant species and new virus species of the group are discovered each year. Begomoviruses are transmitted by members of the whitefly Bemisia tabaci species complex in a persistent-circulative manner. Tomato yellow leaf curl virus (TYLCV) is one of the most devastating begomoviruses worldwide and causes major losses in tomato crops as well as in many agriculturally important plant species. Different B. tabaci populations vary in their virus transmission abilities; however, the causes for these variations are attributed among others to genetic differences among vector populations, as well as to differences in the bacterial symbionts housed within B. tabaci. Here, we performed discovery proteomic analyses in nine whiteflies populations from both Middle East Asia Minor I (MEAM1 formerly known as B biotype) and Mediterranean (MED formerly known as Q biotype) species. We analysed our proteomic results based on the different TYLCV transmission abilities of the various populations included in the study. The results provide the first comprehensive list of candidate insect and bacterial symbiont (mainly Rickettsia) proteins associated with virus transmission. Our data demonstrate that the proteomic signature of better vector populations, differ considerably when compared to less efficient vector ones in the two whitefly species tested in this study. While MEAM1 efficient vector populations has a more lenient immune system, the Q efficient vector populations has higher abundance of proteins possibly implicated in virus passage through cells. Both species show a strong link of the facultative symbiont Rickettsia to virus transmission.