Abstract Detail

The evolution of functional traits in plants: is the giant still sleeping?

McLachlan, Emily Elizabeth [1], Jack, Chandra [1], Petipas, Renee [1], White III, Richard [1], Younginger, Brett [1], Friesen, Maren [2].

Biotic and Abiotic Effects on Belowground Functional Traits in Panicum virgatum.

Evolutionary ecologists consider plants to be autonomous organisms that respond to environmental pressures through plasticity and evolution by natural selection. In reality, symbioses with microbes are an indivisible part of plant ecology and evolution. Microbes affect a wide array of plant functional traits and hence adaptation. However, it is still unclear how biotic and abiotic selective agents interact to affect plant functional traits, especially for belowground traits.
Here we explored how nitrogen availability and microbial community structure affect a suite of belowground traits in Panicum virgatum, commonly known as switchgrass. We were specifically interested in three questions: 1) How do belowground traits respond to nitrogen addition and altered microbial communities? 2) Do nitrogen and microbes interactively or independently affect patterns of selection on belowground traits? 3) Can we identify microbial taxa that correlate with belowground trait values?
We performed a fully factorial experiment where we manipulated nitrogen availability and microbial community structure. We measured how a set of belowground traits, including root length, diameter, and mass, responded to inoculation with field collected microbial communities and the addition of nitrogen. In addition, we collected and extracted rhizosphere material for 16s amplicon sequencing.
We found that the majority of root traits responded to increased soil nitrogen levels but root length and diameter were influenced by microbial community structure and microbes. Similarly, we found that nitrogen overwhelmingly affects patterns of selection on root traits whereas microbes have weaker effects. We were unable to find any microbial taxa that correlated with belowground trait values but are unsure if this is due to low statistical power. Our results suggest that nitrogen may have more pronounced effects on the evolution of belowground plant traits than microbial community structure.

1 - Washington State University, Plant Pathology, 345 Johnson Hall, Pullman, WA, 99164, USA
2 - Plant Pathology, Johnson Hall, Rm 345, Pullman, WA, 99164, United States

Keywords:
Microbiome
functional traits
nitrogen
switchgrass.

Presentation Type: Colloquium Presentations
Session: CO04, The Evolution of Functional Traits in Plant: Is the Giant Still Sleeping?
Location: Tucson J/Starr Pass
Date: Monday, July 29th, 2019
Time: 2:45 PM
Number: CO04006
Abstract ID:940
Candidate for Awards:None