Quantitative fitness effects of infection in a gene-for-gene system
Article first published online: 29 JUL 2009
© The Authors (2009). Journal compilation © New Phytologist (2009)
Volume 184, Issue 2, pages 485–494, October 2009
How to Cite
Gao, L., Roux, F. and Bergelson, J. (2009), Quantitative fitness effects of infection in a gene-for-gene system. New Phytologist, 184: 485–494. doi: 10.1111/j.1469-8137.2009.02959.x
- Issue published online: 25 SEP 2009
- Article first published online: 29 JUL 2009
- Received: 29 April 2009Accepted: 19 May 2009
- Arabidopsis thaliana;
- cost-benefit balance;
- isogenic lines;
- plant–pathogen interactions;
- Pseudomonas syringae;
- RPS5 R gene
- • It is often assumed that pathogen infection decreases plant fitness, thereby driving the evolution of plant resistance (R) genes. However, the impact of bacterial pathogens on fitness has been shown to be relatively subtle, ranging from positive to negative.
- • In this study, we focus on the Rps5-mediated resistance in Arabidopsis thaliana and examine the fitness effects of resistance by experimentally infecting resistant (R) and susceptible (S) plants with a natural avirulent Pseudomonas syringae strain at each of three initial infection dosage levels. Our methodology ensured control of the plant genetic backgrounds; within each of two natural accessions we created isolines varying in the presence or absence of Rps5.
- • In terms of lifetime fitness, R plants outperformed their S controls by 9.6–32% when infected by a pathogen carrying an associated Avr gene, depending on the initial dosage levels and genetic backgrounds.
- • We also found that the naturally R line, Col-0, is more tolerant than the naturally S accession, Ga-0. The negative impact of infection on fitness was 20% less in Col-0 than Ga-0. We found no effect of Rps5 itself on the tolerance of either accession. We therefore failed to find evidence for a trade-off between tolerance and resistance.