The Response of Duckweed Lemna minor to Microplastics and Its Potential Use as a Bioindicator of Microplastic Pollution

Abstract

Biomonitoring has become an indispensable tool for detecting various environmental pollutants, but microplastics have been greatly neglected in this context. They are currently monitored using multistep physico-chemical methods that are time-consuming and expensive, making the search for new monitoring options of great interest. In this context, the aim of this study was to investigate the possibility of using an aquatic macrophyte as a bioindicator of microplastic pollution in freshwaters. Therefore, the effects and adhesion of three types of microplastics (polyethylene microbeads, tire wear particles, and polyethylene terephthalate fibers) and two types of natural particles (wood dust and cellulose particles) to duckweed Lemna minor were investigated. The results showed that fibers and natural particles had no effect on the specific growth rate, chlorophyll a content, and root length of duckweed, while a significant reduction in the latter was observed when duckweed was exposed to microbeads and tire wear particles. The percentage of adhered particles was ten times higher for polyethylene microbeads than for other microplastics and natural particles, suggesting that the adhesion of polyethylene microbeads to duckweed is specific. Because the majority of microplastics in freshwaters are made of polyethylene, the use of duckweed for their biomonitoring could provide important information on microplastic pollution in freshwaters.

Physiological Response of Nutrient-Stressed Lemna gibba to Pulse Colloidal Silver Treatment

“…When plants were treated with pulse colloidal silver–low nutrient level co-exposure, significantly higher levels of H 2 O 2 accumulation and lipid peroxidation were measured in the treated plants, alongside the more pronounced reduction in photosynthetic pigment content in comparison to the same silver pulse treatment combined with high nutrient levels. Rozman and Kalčiková [ 26 ] found that changes in environmental conditions may influence the ability of plants to respond to the abiotic stress factor. The results of this study are in agreement with this statement; external nutrient levels had a significant effect on the L. gibba plant’s response to colloidal silver presence in the environment.…”

“…Duckweed species are suitable model plants due to their high ecological significance as a primary producer and their role in aquatic environments as a source of food and habitat for many different animals [ 24 ], as well as their high sensitivity to numerous potential pollutants [ 25 ]. Additionally, Rozman et al [ 26 ] found that external environmental conditions may affect the abiotic stress response mechanisms of treated duckweed.…”

Insights into the shape-dependent effects of polyethylene microplastics on interactions with organisms, environmental aging, and adsorption properties

“…The measurement for each MPs was repeated three times and the results were expressed as the number particle size distribution. The number of particles per mass of MPs was determined as described in Rozman and Kalčíková 45 . Briefly, approximately 1–2 mg of MPs was weighted and counted under a stereo microscope (SMZ-171, Miotic, China).…”

Microplastic stress in plants: effects on plant growth and their remediations

“…fibers, cellulose particles, and wood dust was examined on the surface of duckweed, and it was found that the adherence of PE MPs was far greater than other tested particles (Rozman and Kalcǐḱova, 2022b). This can be explained by the initial interaction between duckweed and MPs, as negatively charged plant biomass attracts positively charged MPs (Kalcǐḱova, 2020).…”