LB 29-289 - Do microplastic fibres modulate the effect of arbuscular mycorrhizal fungi on its host?

Thursday, August 18, 2022

5:00 PM – 6:30 PM EDT

Located in: ESA Exhibit Hall

Presenting Author(s)

EK

Eric Kanold, BSc

Researcher
University of Guelph - Guelph, ON
Guelph, Ontario, Canada

Coauthor(s)

KD

Kari Dunfield

U of G, Canada
PA

Pedro M. Antunes, PhD

Professor
Algoma University
Sault Ste. Marie, Ontario, Canada

Background/Question/Methods:

Microplastics are an emerging environmental concern. Of all soils types, agricultural soils are at the greatest risk to become contaminated with microplastics. Yet, little is known about their effect on soil organisms, including the association between plants and arbuscular mycorrhizal fungi (AMF). We investigate how the biomass of a model AMF host Sorghum-Sudan grass is affected by increasing levels of microplastic contamination. Plants were grown for 105 days in a completely randomized greenhouse pot experiment with two levels of AMF inoculation (i.e., a community of 12 species and a non-mycorrhizal control) and 4 levels of contamination with a common polyester microplastic fibre (0%, 0.2%, 1.0%, 3.0%). Biomass was collected over 5 consecutive cuts every 21 days, throughout the course of the experiment.

Results/Conclusions:

We performed a repeated measures ANOVA and found very strong evidence that AMF increased the overall growth rate and total biomass of Sorghum-Sudan grass. We also found strong evidence that microplastics affected plant biomass and marginal evidence for an AMF x microplastic interaction. When AMF were absent, overall host biomass increased for greater concentrations of microplastic albeit not in a positive linear manner. However, this effect was not detected when AMF were present. The percent colonization of the roots was examined and it was found that when microplastics were at 0% or 0.2% the colonization rate averaged 85.21% and 85.25% respectively. That dropped to 79.39% AMF colonization at 1% microplastics levels and 70.02% AMF colonization at 3% microplastics. These preliminary data indicate that microplastics in smaller quantities can increase plant biomass. It also shows that microplastics have the ability to interfere with plant growth and can negatively affect AMF symbiosis.