Plants really do feed their friends: new insights into how soil microbiomes might improve carbon storage and plant productivity

  • Researchers prove complex connection between plants and what soil microbes eat
  • Their study could help scientists identify ways to enhance the soil microbiome for improved carbon storage and plant productivity
  • They found that the microbes that flourished in the area around plant roots preferred a diet more rich in organic acids than the less successful microbes in the community.
  • “By controlling the types of microbes that thrive around their roots, plants could be trying to protect themselves from less friendly pathogens while promoting other microbes that stimulate nutrient supply.”

March 22, 2018 DOE/Lawrence Berkeley National Laboratory

Researchers have discovered that as plants develop they craft their root microbiome, favoring microbes that consume very specific metabolites. Their study could help scientists identify ways to enhance the soil microbiome for improved carbon storage and plant productivity….

“For more than a century, it’s been known that plants influence the makeup of their soil microbiome, in part through the release of metabolites into the soil surrounding their roots,” said Berkeley Lab postdoctoral researcher Kateryna Zhalnina, the study’s lead author. “Until now, however, it was not understood whether the contents of this cocktail released by plants was matched by the feeding preferences of soil microbes in a way that would allow plants to guide the development of their external microbiome.”

Microbes within soil improve the ability of plants to absorb nutrients and resist drought, disease, and pests. They mediate soil carbon conversion, affecting the amount of carbon stored in soil or released into the atmosphere as carbon dioxide. The relevance of these functions to agriculture and climate are being observed like never before.

Just one gram of soil contains tens of thousands of microbial species.

…Their study took a close look at the rhizosphere of an annual grass (Avena barbata) common in California and other Mediterranean ecosystems….

…”It’s exciting that we can potentially use the plant’s own chemistry to help nourish beneficial microbes within soil. Population growth, especially, has created a demand for identifying more reliable ways to manipulate the soil microbiome for beneficial outcome.

Kateryna Zhalnina, Katherine B. Louie, Zhao Hao, Nasim Mansoori, Ulisses Nunes da Rocha, Shengjing Shi, Heejung Cho, Ulas Karaoz, Dominique Loqué, Benjamin P. Bowen, Mary K. Firestone, Trent R. Northen, Eoin L. Brodie. Dynamic root exudate chemistry and microbial substrate preferences drive patterns in rhizosphere microbial community assembly. Nature Microbiology, 2018; DOI: 10.1038/s41564-018-0129-3