New Research Reveals Differences in the Function of Fine Roots

Fine plant root systems are critical for assessing ecological processes, including fine-scale biogeochemical cycling and root-microbial relationships. However, microbiome studies rarely focus on fine roots outside of the rhizosphere.

Using a 26-year-old common garden forest, a multi-institutional team of researchers collected fine root samples from four temperate tree species (three deciduous and one coniferous) that varied in their morphology. Through gene sequencing, as well as metabolomic analysis at the Environmental Molecular Sciences Laboratory, a Department of Energy Office of Science user facility, researchers observed that fine roots compartmentalize functions, and within these compartments, bacteria and fungi function differently. This is likely due to whether and how nutritional resources are available in each compartment.

New findings show that the microbiomes in the root surface zone and rhizosphere are distinctive in four different tree species. Results also exhibited differences between the bacterial rhizoplane and rhizosphere compartments for absorptive fine roots, but not transportive fine roots. This research shows the importance of root function when examining root-microbial relationships.

Read about this research led by scientists from Cornell University and Pacific Northwest National Laboratory.