Abstract
Parasites and pathogens are hypothesized to change host growth, reproduction and/or behaviour to increase their own transmission. However, studies which clearly demonstrate that parasites or pathogens are directly responsible for changes in hosts are lacking. We previously found that infection by the systemic fungus Epichloë glyceriae was associated with greater clonal growth by its host, Glyceria striata. Whether greater clonal growth resulted directly from pathogen infection or indirectly from increased likelihood of infection for host genotypes with greater clonal growth could not be determined because only naturally infected and uninfected plants were used. In this study, we decoupled infection and host genotype to evaluate the role of pathogen infection on host development and clonal growth. We found that total biomass production did not differ for clones of the same genotype, but infected clones allocated more biomass to clonal growth. Disinfected clones had more tillers and a greater proportion of their biomass in the mother ramet. Infected clones produced fewer tillers but significantly more and longer stolons than disinfected clones. These results support the hypothesis that pathogen infection directly alters host development. Parasite alteration of clonal growth patterns might be advantageous to the persistence and spread of host plants in some ecological conditions.
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- Batra L. R., Batra S. W. Floral Mimicry Induced by Mummy-Berry Fungus Exploits Host's Pollinators as Vectors. Science. 1985 May 24;228(4702):1011–1013. doi: 10.1126/science.228.4702.1011. [DOI] [PubMed] [Google Scholar]
- Brown S. P., Loot G., Grenfell B. T., Guégan J. F. Host manipulation by Ligula intestinalis: accident or adaptation? Parasitology. 2001 Nov;123(Pt 5):519–529. doi: 10.1017/s0031182001008678. [DOI] [PubMed] [Google Scholar]
- Dobson A. P. The population biology of parasite-induced changes in host behavior. Q Rev Biol. 1988 Jun;63(2):139–165. doi: 10.1086/415837. [DOI] [PubMed] [Google Scholar]
- Franz K., Kurtz J. Altered host behaviour: manipulation or energy depletion in tapeworm-infected copepods? Parasitology. 2002 Aug;125(Pt 2):187–196. doi: 10.1017/s0031182002001932. [DOI] [PubMed] [Google Scholar]
- Gourbal B. E., Righi M., Petit G., Gabrion C. Parasite-altered host behavior in the face of a predator: manipulation or not? Parasitol Res. 2001 Mar;87(3):186–192. doi: 10.1007/pl00008573. [DOI] [PubMed] [Google Scholar]
- Hurd H. Parasite manipulation of insect reproduction: who benefits? Parasitology. 1998;116 (Suppl):S13–S21. doi: 10.1017/s0031182000084900. [DOI] [PubMed] [Google Scholar]
- Knudsen R., Gabler H. M., Kuris A. M., Amundsen P. A. Selective predation on parasitized prey--a comparison between two helminth species with different life-history strategies. J Parasitol. 2001 Oct;87(5):941–945. doi: 10.1645/0022-3395(2001)087[0941:SPOPPA]2.0.CO;2. [DOI] [PubMed] [Google Scholar]
- Lafferty K. D. The evolution of trophic transmission. Parasitol Today. 1999 Mar;15(3):111–115. doi: 10.1016/s0169-4758(99)01397-6. [DOI] [PubMed] [Google Scholar]
- ORENSKI S. W. EFFECTS OF A PLANT VIRUS ON SURVIVAL, FOOD ACCEPTABILITY, AND DIGESTIVE ENZYMES OF CORN LEAFHOOPERS. Ann N Y Acad Sci. 1964 Nov 6;118:374–383. doi: 10.1111/j.1749-6632.1964.tb33986.x. [DOI] [PubMed] [Google Scholar]
- doi: 10.1098/rspb.1999.0812. [DOI] [PMC free article] [Google Scholar]
- Pulkkinen K., Pasternak A. F., Hasu T., Valtonen E. T. Effect of Triaenophorus crassus (Cestoda) infection on behavior and susceptibility to predation of the first intermediate host Cyclops strenuus (Copepoda). J Parasitol. 2000 Aug;86(4):664–670. doi: 10.1645/0022-3395(2000)086[0664:EOTCCI]2.0.CO;2. [DOI] [PubMed] [Google Scholar]
- Schardl C. L. EPICHLOE SPECIES: fungal symbionts of grasses. Annu Rev Phytopathol. 1996;34:109–130. doi: 10.1146/annurev.phyto.34.1.109. [DOI] [PubMed] [Google Scholar]
- Wille Patrick, Boller Thomas, Kaltz Oliver. Mixed inoculation alters infection success of strains of the endophyte Epichloë bromicola on its grass host Bromus erectus. Proc Biol Sci. 2002 Feb 22;269(1489):397–402. doi: 10.1098/rspb.2001.1889. [DOI] [PMC free article] [PubMed] [Google Scholar]