title: Viral pathogen production in a wild grass host driven by host growth and soil nitrogen.
abstract: Nutrient limitation is a basic ecological constraint that has received little attention in studies on virus production and disease dynamics. Nutrient availability could directly limit the production of viral nucleic acids and proteins, or alternatively limit host growth and thus indirectly limit metabolic pathways necessary for viral replication. In order to compare direct and indirect effects of nutrient limitation on virus production within hosts, we manipulated soil nitrogen (N) and phosphorus (P) availability in a glasshouse for the wild grass host Bromus hordeaceus and the viral pathogen Barley yellow dwarf virus-PAV. We found that soil N additions increased viral concentrations within host tissues, and the effect was mediated by host growth. Specifically, in statistical models evaluating the roles of host biomass production, leaf N and leaf P, viral production depended most strongly on host biomass, rather than the concentration of either nutrient. Furthermore, at low soil N, larger plants supported greater viral concentrations than smaller ones, whereas at high N, smaller plants supported greater viral concentrations. Our results suggest that enhanced viral productivity under N enrichment is an indirect consequence of nutrient stimulation to host growth rate. Heightened pathogen production in plants has important implications for a world facing increasing rates of nutrient deposition.
authors.affiliation: Department of Biology, University of North Carolina, Coker Hall, CB #3280, 120 South Road, Chapel Hill, NC, 27599-3280, USA.|Department of Biology, Indiana University, Jordan Hall, 1001 E. 3rd St, Bloomington, IN, 47405-3700, USA.
authors.forename: Briana K
authors.initials: BK
authors.lastname: Whitaker
authors.affiliation: Curriculum for the Environment and Ecology, University of North Carolina, 3301 Venable Hall, CB# 3275, Chapel Hill, NC, 27599-3135, USA.|Department of Biology, University of Mississippi, 214 Shoemaker Hall, University, MS, 38677, USA.
authors.forename: Megan A
authors.identifier: http://orcid.org/0000-0002-2883-2795
authors.initials: MA
authors.lastname: Rúa
authors.affiliation: Department of Biology, University of North Carolina, Coker Hall, CB #3280, 120 South Road, Chapel Hill, NC, 27599-3280, USA.|Curriculum for the Environment and Ecology, University of North Carolina, 3301 Venable Hall, CB# 3275, Chapel Hill, NC, 27599-3135, USA.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Mitchell
mesh_terms: D018533:Biomass; D031724:Bromus / Q000187:drug effects / Q000254:growth & development* / Q000821:virology*; D054884:Host-Pathogen Interactions / Q000187:drug effects*; D017793:Luteovirus / Q000187:drug effects / Q000254:growth & development*; D009584:Nitrogen / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects / Q000821:virology; D012987:Soil / Q000737:chemistry*; D019562:Viral Load / Q000187:drug effects
chemical_list: D012987:Soil; D009584:Nitrogen
keywords: Barley Yellow Dwarf Virus; Bromus hordeaceus; disease ecology; host growth rate; nutrient limitation; plant-pathogen interactions