22 January 2018
Results are consistent with the “optimal foraging theory,” suggesting that communities readily shift resources as nutrient availabilities change.
The Oak Ridge National Laboratory (ORNL) research team identified many more genes in soil microbial communities for producing enzymes to acquire phosphorus in phosphorus-starved tropical ecosystems as compared to phosphorus-rich environments.
Results suggest a major source of phosphorus is the complex phytate (inositol phosphate) molecule, which was thought to be difficult for organisms to access. Microbial communities acquire nutrients depending on fertility, focusing on phosphorus when it is in short supply but switching to carbon, nitrogen, and sulfur when phosphorus is plentiful. Therefore, tropical soil communities can be very resourceful in acquiring rare nutrients.
ORNL researchers teamed with the Smithsonian Tropical Research Institute and three DOE user facilities—Joint Genome Institute, Oak Ridge Leadership Computing Facility, and Environmental Molecular Sciences Laboratory—to examine the genes of soil microbes in the Smithsonian’s 17-year-old phosphorus fertilization experiment in the Republic of Panama. The researchers found that there were many more genes for phosphorus acquisition in the soils when compared to soils that had received phosphorus fertilization. Surprisingly, over 100 genes were found to produce the enzyme phytase, which removes phosphorus from the complex phytate molecule. The genes to acquire phytate were widely distributed in the microbial communities. Further, when phosphorus was plentiful, soil microbial communities had more genes to break down complex carbon molecules and to acquire nitrogen and sulfur. The results are consistent with the “optimal foraging theory,” which suggests that communities readily shift resources as nutrient availabilities change.
BER Program Manager
Terrestrial Ecosystem Science, SC-23.1
Oak Ridge National Laboratory
Oak Ridge, TN 37831
This work was supported by Laboratory Directed Research and Development funding from Oak Ridge National Laboratory.
Yao, Q., Li, Z., Song, Y., et al. “Community proteogenomics reveals the systemic impact of phosphorus availability on microbial functions in tropical soil.” Nature Ecology and Evolution 2, 499–509 (2018). [DOI:10.1038/s41559-017-0463-5]
ORNL News: Researchers reveal how microbes cope in phosphorus-deficient tropical soil
Smithsonian News: TITAN Supercomputer Reveals How Microbes Cope With Scarcity
Melanie A Mayes DOE Early Career Award. The Joint Genome Institute was used for sequencing, the Oak Ridge Leadership Computing Facility was used for gene assembly, the Environmental Molecular Sciences Laboratory was used for analysis of soil organic matter.