Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Pickett, Brooke [1], Carey:, Chelsea J. [2], Arogyaswamy, Keshav [2], Botthoff, Jon [3], Maltz, Mia [3], Catalan, Pilar [4], Aronson, Emma [2].

Enriched root bacterial microbiome in invaded vs native ranges of the model grass allotetraploid Brachypodium hybridum.

Invasive plant species are disrupting natural areas around the world. Invasive species can shift the composition of key soil microbial groups, thus creating novel soil microbial communities. To better understand the biological drivers of invasion, we studied plant-microbial interactions in species of the Brachypodium distachyon complex, a model system for functional genomic studies of temperate grasses and bioenergy crops which contain plants native to the Mediterranean region including the allotetraploid invader B. hybridum. While Brachypodium hybridum invasion in California is currently in an incipient stage, threatening natural and agricultural systems, its diploid progenitor species B. distachyon is not invasive in California. We investigated the root, soil, and rhizosphere bacterial composition of Brachypodium hybridum in both its native and invaded range, and of B. distachyon in the native range. We used high-throughput, amplicon sequencing to evaluate if the bacteria associated with these plants differ, and whether biotic controls may be driving B. hybridum invasion. Bacterial community composition of B. hybridum differed based on provenance (native or invaded range) for root, rhizosphere and bulk soils, as did the abundance of dominant bacterial taxa. Brachypodium hybridum roots were more diverse in the invaded range, as compared to roots from the native range. Root bacterial composition differed between B. hybridum and B. distachyon in the native range, while rhizosphere soil and bulk soil composition was equivalent. Bacteroidetes, Cyanobacteria and Bacillus spp. were significantly more abundant in B. hybridum roots from the invaded range, whereas Proteobacteria, Firmicutes, Erwinia and Pseudomonas were more abundant in the native range roots. The Cyanobacterial symbiosis may occur in drier invaded habitats, whereas root-associated pathogen bacteria may be lower within the invaded range, facilitating the invasiveness of B. hybridum. Brachypodium hybridum forms novel biotic interactions with a diverse suite of rhizosphere microbes from the invaded range, which may not exert a similar influence within its native range, ostensibly contributing to B. hybridum’s invasiveness. These associated plant microbiomes could inform future management approaches for B. hybridum in its invaded range. These dynamics could be key to understanding, predicting, and preventing future plant invasions.

1 - University of California San Diego, 1) Division of Biological Sciences, San Diego, CA, USA
2 - University of California Riverside, Microbiology and Plant Pathology, Riverside, CA, USA
3 - University of California Riverside, Center for Conservation Biology, Riverside, CA, USA
4 - University of Zaragoza: Universidad de Zaragoza, Agricultural and Environmental Sciences, High Polytechnic School of Huesca, Ctra. Cuarte km 1, Huesca, Aragón, 22071, Spain

Keywords:
Brachypodium
invasive especies
endophytic bacteria
Rhizosphere
root
soil.

Presentation Type: Poster
Session: P3, Symbioses: Plant, Animal, and Microbe Interactions Posters
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 5:00 PM(EDT)
Number: P3SM008
Abstract ID:656
Candidate for Awards:None