03/15/2017

Phosphate Stress and Immunity Systems in Plants are Orchestrated by the Root Microbial Community

Better understanding of these plant-microbe interactions could lead to improved bioenergy feedstocks.

The Science

The microbial community associated with plant roots coordinates the simultaneous response of plants to both nutrient stress and disease. In a recent study, researchers established that a genetic network controlling the phosphate stress response influences how the root microbiome community is structured, even under nonstress phosphate conditions.

The Impact

Understanding how plants interact with beneficial soil microbial communities may lead to novel approaches for breeding high-yielding bioenergy feedstocks on marginal lands with few inputs. This study, for the first time, provides evidence that genes controlling phosphate starvation response (PSR) and plant defense regulation are coordinated.

Summary

To become a sustainable and viable source of biofuels, biomass feedstock crops must be capable of high productivity on marginal lands not fit for food crop production. Nutrients such as phosphorus are critical to plant productivity but are scarce in low-fertility soils, so breeding biomass plants that efficiently utilize nutrients even in nutrient-depleted soils is critical to their use as a sustainable and cost-effective bioenergy resource. Plants form intimate associations with the soil microbial communities that surround their root systems. These communities are diverse and can contain both pathogenic microbes that compete with the plant for nutrients as well as beneficial microbes that increase plant health, vigor, and productivity. Soil nutrient content can influence the composition of the microbial community, but the mechanisms are unknown. Researchers at the University of North Carolina at Chapel Hill, with partial funding from the U.S. Department of Energy-U.S.Department of Agriculture Plant Feedstocks Genomics for Bioenergy program, used mutants of the model plant Arabidopsis thaliana with altered PSR to show that genes controlling PSR contribute to normal root microbiome assembly. They discovered that the regulatory gene PHR1 can fine-tune this response. They further showed that PSR regulation and pathogen defense are coordinated, providing insight into the coordinated interchange of plant response to nutritional stress, the plant immune system, and the root microbiome, as well as a foundational basis for using the soil microbiome to enhance phosphate use efficiency in plants.

Principal Investigator(s)

Jeffery L. Dangl
University of North Carolina at Chapel Hill
dangl@email.unc.edu

Funding

Partial support for this work was provided by the U.S. Department of Energy-U.S. Department of Agriculture Plant Feedstock Genomics for Bioenergy (award DE-SC001043) and National Science Foundation INSPIRE grant IOS-1343020.

References

Castrillo, G., P. J. P. L. Teixeira, S. H. Paredes, T. F. Law, L. de Lorenzo, M. E. Feltcher, O. M. Finkel, N. W. Breakfield, P. Mieczkowski, C. D. Jones, J. Paz-Ares, and J. L. Dangl. 2017. “Root Microbiota Drive Direct Integration of Phosphate Stress and Immunity,” Nature 543, 513-18. DOI: 10.1038/nature21417.