We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
The fate of biodegradable polylactic acid microplastics in maize: impacts on cellular ion fluxes and plant growth
Summary
Researchers exposed maize plants to PLA biodegradable microplastics via seed germination and hydroponic experiments for up to 20 days at concentrations of 0–100 mg/L. Low concentrations (1 mg/L) had minimal effect, but higher concentrations disrupted cellular ion fluxes (Ca²⁺, H⁺, K⁺) and reduced plant growth, demonstrating that biodegradable MPs are not ecologically inert in agricultural crops.
The widespread application of biodegradable microplastics (MPs) in recent years has resulted in a significant increase in their accumulation in the environment, posing potential threats to ecosystems. Thus, it is imperative to evaluate the distribution and transformation of biodegradable MPs in crops due to the utilization of wastewater containing MPs for irrigation and plastic films, which have led to a rising concentration of biodegradable MPs in agricultural soils. The present study analyzed the uptake and transformation of polylactic acid (PLA) MPs in maize. Seed germination and hydroponic experiments were conducted over a period of 5 to 20 days, during which the plants were exposed to PLA MPs at concentrations of 0, 1, 10, and 100 mg L-1. Low concentrations of PLA MPs (1 mg L-1 and 10 mg L-1) significantly enhanced maize seed germination rate by 52.6%, increased plant shoot height by 16.6% and 16.9%, respectively, as well as elevated aboveground biomass dry weight by 133.7% and 53.3%, respectively. Importantly, depolymerization of PLA MPs was observed in the nutrient solution, resulting in the formation of small-sized PLA MPs (< 2 μm). Interestingly, further transformation occurred within the xylem sap and apoplast fluid (after 12 h) with a transformation rate reaching 13.1% and 27.2%, respectively. The enhanced plant growth could be attributed to the increase in dissolved organic carbon resulting from the depolymerization of PLA MPs. Additionally, the transformation of PLA MPs mediated pH and increase in K+ flux (57.2%, 72 h), leading to acidification of the cell wall and subsequent cell expansion. Our findings provide evidence regarding the fate of PLA MPs in plants and their interactions with plants, thereby enhancing our understanding of the potential impacts associated with biodegradable plastics.
Sign in to start a discussion.
More Papers Like This
Unveiling the detrimental effects of polylactic acid microplastics on rice seedlings and soil health
Researchers found that even biodegradable polylactic acid (PLA) microplastics significantly harmed rice plants at high concentrations, reducing root and shoot weight by roughly half and disrupting photosynthesis, while also altering soil enzyme activity and bacterial communities. These findings challenge the assumption that biodegradable plastics are harmless to agriculture and raise questions about their impact on food crops that humans depend on.
Plant Cadmium Toxicity and Biomarkers Are Differentially Modulated by Degradable and Nondegradable Microplastics in Soil
Researchers compared how degradable (polylactic acid) and nondegradable (polypropylene) microplastics affect cadmium toxicity in plants grown in contaminated soil. They found that polypropylene caused greater root growth inhibition, while polylactic acid led to higher levels of cellular stress markers at certain concentrations. The study reveals that both types of microplastics can alter soil chemistry and increase the uptake of heavy metals by crops, but through different mechanisms.
Transcriptomic and metabolomic responses of maize under conventional and biodegradable microplastic stress
Researchers studied how both conventional and biodegradable microplastics affect maize at the molecular level, finding that both types altered plant metabolism and triggered stress responses. The microplastics changed how the plants handled energy, photosynthesis, and hormone signaling, with effects varying by plastic type. This is concerning for food safety because microplastic-contaminated soil could change the nutritional quality or safety of crops that people eat.
Effect of polylactic acid microplastics on soil properties, soil microbials and plant growth
Researchers tested whether microplastics from biodegradable polylactic acid plastic, often proposed as an eco-friendly alternative to conventional plastic, affect soil health and plant growth. High concentrations of these biodegradable microplastics reduced soil pH, altered the ratio of carbon to nitrogen, decreased plant growth, and shifted soil microbial communities. The study suggests that even biodegradable plastics can negatively affect agricultural ecosystems when they break down into microplastic-sized particles.
Transcription-metabolism analysis of various signal transduction pathways in Brassica chinensis L. exposed to PLA-MPs
Researchers used gene and metabolite analysis to study how microplastics from biodegradable polylactic acid (PLA) plastic affect the growth of Chinese cabbage. They found that PLA microplastics altered the expression of genes involved in plant hormone signaling and metabolism, and changed levels of key amino acids and metabolic compounds. The study suggests that even biodegradable plastics can disrupt plant development at the molecular level, warranting further investigation.