Interactions among co-infecting pathogens are common across host taxa and can affect infectious disease dynamics. Host nutrition can mediate these among-pathogen interactions, altering the establishment and growth of pathogens within hosts. It is unclear, however, how nutrition-mediated among-pathogen interactions affect transmission and the spread of disease through populations. We manipulated the nitrogen (N) and phosphorus (P) supplies to oat plants in growth chambers and evaluated interactions between two aphid-vectored Barley and Cereal Yellow Dwarf Viruses: PAV and RPV. We quantified the effect of each virus on the other’s establishment, within-plant density, and transmission. Co-inoculation significantly increased PAV density when N and P supplies were low and tended to increase RPV density when N supply was high. Co-infection increased PAV transmission when N and P supplies were low and tended to increase RPV transmission when N supply was high. Despite the parallels between the effects of among-pathogen interactions on density and transmission, changes in virus density only partially explained changes in transmission, suggesting that virus density-independent processes contribute to transmission. A mathematical model describing the spread of two viruses through a plant population, parameterized with empirically derived transmission values, demonstrated that nutrition-mediated among-pathogen interactions could affect disease spread. Interactions that altered transmission through virus density-independent processes determined overall disease dynamics. Our work suggests that host nutrition alters disease spread through among-pathogen interactions that modify transmission.
Bibliographical noteFunding Information:
We are grateful to Christelle Lacroix, Melissa Rudeen, Anita Krause, Nicholas Cupery, Casey Easterday, Kurra Renner, Luc Robichaud, and Alexis Rogers for help with the experiment and to multiple anonymous reviewers for their comments on earlier drafts. A. E. Kendig was supported by an NSF IGERT graduate fellowship at the University of Minnesota (DGE-0653827) and an NSF Graduate Research Fellowship (base award number 006595) and E. T. Borer and E. W. Seabloom received support from the NSF program in Ecology and Evolution of Infectious Diseases (grant DEB-1015805). A. E. Kendig, E. T. Borer, and E. W. Seabloom designed the experiment, A. E. Kendig, E. N. Boak, and T. C. Picard performed the experiment and analyses, A. E. Kendig wrote the first draft, and all authors contributed to revisions.
- Avena sativa
- barley and cereal yellow dwarf viruses
- disease spread
- Rhopalosiphum padi
- within-host pathogen density
PubMed: MeSH publication types
- Journal Article