Journal
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
Volume 273, Issue 1582, Pages 77-81Publisher
ROYAL SOCIETY
DOI: 10.1098/rspb.2005.3292
Keywords
exploitation; cooperation; symbiosis; mutualism; nitrogen fixation; sanctions
Categories
Funding
- NIGMS NIH HHS [GM48983, R25 GM048983] Funding Source: Medline
Ask authors/readers for more resources
Mutualisms can be viewed as biological markets in which partners of different species exchange goods and services to their mutual benefit. Trade between partners with conflicting interests requires mechanisms to prevent exploitation. Partner choice theory proposes that individuals might foil exploiters by preferentially directing benefits to cooperative partners. Here, we test this theory in a wild legume-rhizobium symbiosis. Rhizobial bacteria inhabit legume root nodules and convert atmospheric dinitrogen (N-2) to a plant available form in exchange for photosynthates. Biological market theory suits this interaction because individual plants exchange resources with multiple rhizobia. Several authors have argued that microbial cooperation could be maintained if plants preferentially allocated resources to nodules harbouring cooperative rhizobial strains. It is well known that crop legumes nodulate non-fixing rhizobia, but allocate few resources to those nodules. However, this hypothesis has not been tested in wild legumes which encounter partners exhibiting natural, continuous variation in symbiotic benefit. Our greenhouse experiment with a wild legume, Lupinus arboreus, showed that although plants frequently hosted less cooperative strains, the nodules occupied by these strains were smaller. Our survey of wild-grown plants showed that larger nodules house more Bradyrhizobia, indicating that plants may prevent the spread of exploitation by favouring better cooperators.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available