S PAUL, N. D., & AYRES, P. G. (1986). INTERFERENCE BETWEEN HEALTHY AND RUSTED GROUNDSEL (SENECIO VULGARIS L.) WITHIN MIXED POPULATIONS OF DIFFERENT DENSITIES AND PROPORTIONS. New Phytologist, 104(2), 257-269. doi:10.1111/j.1469-8137.1986.tb00650.x

Competition and parasitism are two important selective forces that shape life-histories, migration rates and population dynamics. Recently, it has been shown in various pathosystems that parasites can modify intraspecific competition, thus generating an indirect cost of parasitism. Here, we investigated if this phenomenon was present in a plant-potyvirus system using two viruses of different virulence (Tobacco etch virus and Turnip mosaic virus). Moreover, we asked if parasitism interacted with the shade avoidance syndrome, the plant-specific phenotypic plasticity in response to intraspecific competition. Our results indicate that the modification of intraspecific competition by parasitism is not present in the Nicotiana benthamiana ¿ potyvirus system and suggests that this phenomenon is not universal but depends on the peculiarities of each pathosystem. However, whereas the healthy N. benthamiana presented a clear shade avoidance syndrome, this phenotypic plasticity totally disappeared when the plants were infected with TEV and TuMV, very likely resulting in a fitness loss and being another form of indirect cost of parasitism. This result suggests that the suppression or the alteration of adaptive phenotypic plasticity might be a component of virulence that is often overlooked. This work has been supported by grants BFU2009-06993 (Ministerio de Ciencia e Innovacion, Spain) and PROMETEO2010-019 (Generalitat Valenciana) (S.F.E.) and a CSIC JAE-Doc contract (S.B.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Bedhomme ., S.; Elena Fito, SF. (2011). Virus infections suppresses Nicotiana benthamiana adaptive phenotypic plasticity. PLoS ONE. 6:17275-17275. doi:10.1371/journal.pone.0017275 Santos, M., Borash, D. J., Joshi, A., Bounlutay, N., & Mueller, L. D. (1997). Density-Dependent Natural Selection in Drosophila: Evolution of Growth Rate and Body Size. Evolution, 51(2), 420. doi:10.2307/2411114 Borash, D. J., Gibbs, A. G., Joshi, A., & Mueller, L. D. (1998). A Genetic Polymorphism Maintained by Natural Selection in a Temporally Varying Environment. The American Naturalist, 151(2), 148-156. doi:10.1086/286108 Franklin, K. A. (2008). Shade avoidance. New Phytologist, 179(4), 930-944. doi:10.1111/j.1469-8137.2008.02507.x Dudley, S. A., & Schmitt, J. (1996). Testing the Adaptive Plasticity Hypothesis: Density-Dependent Selection on Manipulated Stem Length in Impatiens capensis. The American Naturalist, 147(3), 445-465. doi:10.1086/285860 Bedhomme, S., Agnew, P., Vital, Y., Sidobre, C., & Michalakis, Y. (2005). Prevalence-Dependent Costs of Parasite Virulence. PLoS Biology, 3(8), e262. doi:10.1371/journal.pbio.0030262 Finckh, M. R., & Mundt, C. C. (1996). Temporal Dynamics of Plant Competition in Genetically Diverse Wheat Populations in the Presence and Absence of Stripe Rust. The Journal of Applied Ecology, 33(5), 1041. doi:10.2307/2404684 Burdon, J. J., Groves, R. H., Kaye, P. E., & Speer, S. S. (1984). Competition in mixtures of susceptible and resistant genotypes of Chondrilla juncea differentially infected with rust. Oecologia, 64(2), 199-203. doi:10.1007/bf00376871 Damgaard, C., & Jensen, B. D. (2002). Disease resistance in Arabidopsisthaliana increases the competitive ability and the predicted probability of long-term ecological success under disease pressure. Oikos, 98(3), 459-466. doi:10.1034/j.1600-0706.2002.980310.x FRIESS, N., & MAILLET, J. (1996). Influence of cucumber mosaic virus infection on the intraspecific competitive ability and fitness of purslane (Portulaca oleracea). New Phytologist, 132(1), 103-111. doi:10.1111/j.1469-8137.1996.tb04514.x Sisterson, M. S., & Averill, A. L. (2003). Interactions between parasitized and unparasitized conspecifics: parasitoids modulate competitive dynamics. Oecologia, 135(3), 362-371. doi:10.1007/s00442-003-1205-8 Koprivnikar, J., Forbes, M. R., & Baker, R. L. (2007). Larval amphibian growth and development under varying density: are parasitized individuals poor competitors? Oecologia, 155(3), 641-649. doi:10.1007/s00442-007-0937-2 Carrasco, P., de la Iglesia, F., & Elena, S. F. (2007). Distribution of Fitness and Virulence Effects Caused by Single-Nucleotide Substitutions in Tobacco Etch Virus. Journal of Virology, 81(23), 12979-12984. doi:10.1128/jvi.00524-07 KLECZKOWSKI, A. (1949). THE TRANSFORMATION OF LOCAL LESION COUNTS FOR STATISTICAL ANALYSIS. Annals of Applied Biology, 36(1), 139-152. doi:10.1111/j.1744-7348.1949.tb06404.x Gotthard, K., Nylin, S., & Nylin, S. (1995). Adaptive Plasticity and Plasticity as an Adaptation: A Selective Review of Plasticity in Animal Morphology and Life History. Oikos, 74(1), 3. doi:10.2307/3545669 Bedhomme, S., Agnew, P., Sidobre, C., & Michalakis, Y. (2004). Virulence reaction norms across a food gradient. Proceedings of the Royal Society of London. Series B: Biological Sciences, 271(1540), 739-744. doi:10.1098/rspb.2003.2657 RIVERO, A., AGNEW, P., BEDHOMME, S., SIDOBRE, C., & MICHALAKIS, Y. (2007). Resource depletion in Aedes aegypti mosquitoes infected by the microsporidia Vavraia culicis. Parasitology, 134(10), 1355-1362. doi:10.1017/s0031182007002703 Jokela, J., Lively, C. M., Taskinen, J., & Peters, A. D. (1999). Effect of starvation on parasite-induced mortality in a freshwater snail ( Potamopyrgus antipodarum). Oecologia, 119(3), 320-325. doi:10.1007/s004420050792 Jokela, J., Taskinen, J., Mutikainen, P., & Kopp, K. (2005). Virulence of parasites in hosts under environmental stress: experiments with anoxia and starvation. Oikos, 108(1), 156-164. doi:10.1111/j.0030-1299.2005.13185.x Brown, M. J. F., Loosli, R., & Schmid-Hempel, P. (2000). Condition-dependent expression of virulence in a trypanosome infecting bumblebees. Oikos, 91(3), 421-427. doi:10.1034/j.1600-0706.2000.910302.x Ferguson, H. M., & Read, A. F. (2002). Genetic and environmental determinants of malaria parasite virulence in mosquitoes. Proceedings of the Royal Society of London. Series B: Biological Sciences, 269(1497), 1217-1224. doi:10.1098/rspb.2002.2023 VALE, P. F., STJERNMAN, M., & LITTLE, T. J. (2008). Temperature-dependent costs of parasitism and maintenance of polymorphism under genotype-by-environment interactions. Journal of Evolutionary Biology, 21(5), 1418-1427. doi:10.1111/j.1420-9101.2008.01555.x

Virus infections suppresses Nicotiana benthamiana adaptive phenotypic plasticity

Abstract