Bacteria and fungi are key components of virtually all natural habitats, yet the significance of fungal-bacterial inhibitory interactions for the ecological and evolutionary dynamics of specific bacterial and fungal populations in natural habitats have been overlooked. More specifically, despite the broad consensus that antibiotics play a key role in providing a fitness advantage to competing microbes, the significance of antibiotic production in mediating cross-kingdom coevolutionary interactions has received relatively little attention. Here, we characterize reciprocal inhibition among Streptomyces and Fusarium populations from prairie soil, and explore antibiotic inhibition in relation to niche overlap among sympatric and allopatric populations. We found evidence for local adaptation between Fusarium and Streptomyces populations as indicated by significantly greater inhibition among sympatric than allopatric populations. Additionally, for both taxa, there was a significant positive correlation between the strength of inhibition against the other taxon and the intensity of resource competition from that taxon among sympatric but not allopatric populations. These data suggest that coevolutionary antagonistic interactions between Fusarium and Streptomyces are driven by resource competition, and support the hypothesis that antibiotics act as weapons in mediating bacterial–fungal interactions in soil.
Bibliographical noteFunding Information:
We thank the Cedar Creek Ecosystem Science Reserve for permission to collect soil samples. We also thank the staff in our laboratory, including especially Lindsey Hanson, for their help and feedback to improve this work. Research was supported by Agricultural and Food Research Grant Initiative Competitive Grant No. 2011-67019-30200 from the USDA National Institute of Food and Agriculture. A. Essarioui received full support from the Islamic Development Bank.
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.