Nitrogen Fixation by Endophytes of Populus
EMSL Project ID
49833
Abstract
To improve the environmental and economic sustainability of biomass production, it is essential that the biological interactions between plants and associated beneficial microbiota be more fully understood in order to design and optimize these microbial endophyte communities. Native poplar (Populus) plants have a diverse microbiota, some of which can promote plant growth and health under abiotic stresses including nutrient deficiency and drought. Our lab demonstrated that atmospheric nitrogen (N) is fixed at high levels in wild poplar by endophytes, at variable levels in different cuttings. Addition of a collection of the wild poplar endophytes to hybrid poplar resulted in increased growth and N-fixation. In the proposed research on constructed microbial communities in vitro and in sterile poplar plants, we will investigate the dynamics of N-fixation. Using Laser Capture Microdissection microscopy and transcriptomics, we will determine which N metabolism endophyte genes are expressed in plants colonized by our sequenced N-fixing strains. We will investigate the role of the observed microcolonies first in vitro, using Fluorescent in situ hybridization and NanoSIMS to determine N-fixation activity and N transfer within the biofilms. We will then decipher if the aggregates actively fix N within the plant and transfer fixed N to the host cells. Our earlier quantification of N-fixation within wild poplar was the first step in helping explain the biology of poplar as a pioneer plant species. Increased growth and N-fixation in hybrid poplar through the addition of a consortium of wild poplar endophytes to hybrid poplar demonstrated the utility of this knowledge. With the successful completion of the proposed project, new insights will be gained into the interactions of poplar's microbial endophyte community and an understanding of how N fixation and transfer can be achieved. Understanding the functional role of the microbiome of this early successional pioneer plant species may not only provide insight on how to optimize this one species' biomass, but also provide critical insights into how microbial endophytes can increase production of other plant species on marginal lands and with fewer inputs.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2017-10-01
End Date
2019-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Poster presentation "Phosphorous fixation in Populus as seen by synchrotron fluorescence spectromicroscopy and microtomography", Tamas Varga, Amir Ahkami, Rosalie Chu, Sirine Fakra, Dula Parkinson, Sharon Doty, ALS User Meeting 2018, Advanced Light Source, Berkeley, CA, October 2, 2018