Tree species effects on pathogen-suppressive capacities of soil bacteria across two tropical dry forests in Costa Rica
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- 作者：Kristen Becklund ; Jennifer Powers ; Linda Kinkel
- 关键词：Streptomyces ; Disease suppression ; Antibiotics ; Soil nutrients ; Leaf litter
- 刊名：Oecologia
- 出版年：2016
- 出版时间：November 2016
- 年：2016
- 卷：182
- 期：3
- 页码：789-802
- 全文大小：978 KB
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Life Sciences
Ecology
Plant Sciences - 出版者：Springer Berlin / Heidelberg
- ISSN：1432-1939
- 卷排序：182
文摘
Antibiotic-producing bacteria in the genus Streptomyces can inhibit soil-borne plant pathogens, and have the potential to mediate the impacts of disease on plant communities. Little is known about how antibiotic production varies among soil communities in tropical forests, despite a long history of interest in the role of soil-borne pathogens in these ecosystems. Our objective was to determine how tree species and soils influence variation in antibiotic-mediated pathogen suppression among Streptomyces communities in two tropical dry forest sites (Santa Rosa and Palo Verde). We targeted tree species that co-occur in both sites and used a culture-based functional assay to quantify pathogen-suppressive capacities of Streptomyces communities beneath 50 focal trees. We also measured host-associated litter and soil element concentrations as potential mechanisms by which trees may influence soil microbes. Pathogen-suppressive capacities of Streptomyces communities varied within and among tree species, and inhibitory phenotypes were significantly related to soil and litter element concentrations. Average proportions of inhibitory Streptomyces in soils from the same tree species varied between 1.6 and 3.3-fold between sites. Densities and proportions of pathogen-suppressive bacteria were always higher in Santa Rosa than Palo Verde. Our results suggest that spatial heterogeneity in the potential for antibiotic-mediated disease suppression is shaped by tree species, site, and soil characteristics, which could have significant implications for understanding plant community composition and diversity in tropical dry forests.