Towards understanding the Panicum virgatum microbiome - switchgrass geno-/ecotype and treatment practices influence the microbial community
E. SINGER (1), T. Juenger (2), T. Woke (1) (1) Joint Genome Institute, U.S.A.; (2) University of Texas Austin, U.S.A.

Growing energy demands and concerns for climate change have urgently pushed forward the timeline for the implementation of biofuel energies. There are still surprisingly large gaps in our understanding of switchgrass, Panicum virgatum, which has been championed as one promising biofuel species. This study looks at critical plant-microbe-soil traits that may be manipulated, through breeding or agronomic management, to improve the sustainability switchgrass. Using V4 16S rRNA as well as metagenome sequencing, we studied the bacterial and fungal microbiome in four different genotypes of switchgrass plants, including upland and lowland ecotypes, which were subjected to various fertilization and harvest treatments. Microbial community composition was studied in leaf episphere, leaf endosphere, root episphere, root endosphere, and surrounding soil. We observed 1000s of bacterial and archaeal, as well as 100s of fungal OTUs. Ordination analysis shows that both, microbial community structure and richness, are distinct according to niche origin at the family and genus level. In all compartments, differences in community composition were mainly explained by harvest practice (~33% in the bacteria and archaea, 21-32% in the fungi) and geno-/ecotype differences (39 - 59% in the bacteria and archaea, 25-43% in the fungi). Indicator species and differential abundance analysis by factor grouping are complemented with functional gene analysis associated with switchgrass geno- and ecotype, as well as harvest practice. This dataset is the first to discuss the switchgrass microbiome and allows insight into important microbial players associated with various switchgrass growth scenarios.

Abstract Number: P11-378
Session Type: Poster