Mulberry (Morus alba L.) leaves are widely used as functional food and medicinal-food raw materials, yet the influence of soil microplastic contamination on their quality formation remains insufficiently understood. In this study, a 45-day pot experiment with 3–4 biological replicates was conducted to compare the effects of conventional polyethylene (PE) and biodegradable poly (butylene succinate) (PBS) microplastics at graded soil application rates on mulberry seedling growth, tissue ultrastructure, antioxidant-related quality attributes, and metabolic profiles. PE and PBS suppressed mulberry height, stem diameter and biomass in a dose-dependent way (p < 0.05). At 400 mg/kg, PE reduced plant height, stem diameter and fresh biomass by 34.7%, 30.8% and 31.4%, while PBS caused larger declines of 45.5%, 39.8% and 42.5%; total dry biomass dropped maximally by 34.2% under PE and 46.8% under PBS. Both treatments triggered 31.8% compensatory root elongation potentially for nutrient capture, yet PBS induced more severe root pore blockage and leaf cuticle damage than PE across tested concentrations. MP exposure raised leaf total flavonoids and phenolics markedly. At 400 mg/kg, PE and PBS boosted flavonoids by 82.8% and 90.9%, phenolics by 90.1% and 100.8%. Meanwhile, 400 mg/kg PE and PBS increased DPPH activity by 65.9% and 73.5%, ABTS activity by 66.3% and 74.4% relative to the control. Non-targeted metabolomics demonstrated pronounced shifts in the leaf metabolic profiles, characterized by the accumulation of coumaric acid, quercetin, and rutin, while glutathione levels declined. KEGG analysis identified phenylpropanoid and flavonoid biosynthesis as core responsive pathways; high PBS levels strongly disturbed lipid and stress metabolism. Overall, microplastic stress induced a trade-off between vegetative growth and antioxidant-oriented secondary metabolism in mulberry leaves. These findings suggest that biodegradable PBS residues can induce prominent physiological variations during the initial crop production stage, which highlights the need to closely track their temporal effects on functional raw materials.
Microplastic (MP) contamination in agroecosystems is an increasingly recognized environmental concern, whereas its polymer‐specific impacts on plant growth and nutritional composition remain poorly understood.
Our study aimed to evaluate how polymer type and concentration of MPs directly affect plant growth, physiological traits, and nutrient balance under hydroponic conditions.
Maize (
Zea mays
L.) seedlings were exposed to polypropylene (PP) and polyethylene (PE) MPs at two concentrations (50 and 200 mg L
−1
) in a hydroponic system, thus unravelling direct root–particle interactions from soil‐mediated effects. The experiment was independently repeated under similar conditions to validate the reproducibility of MP‐induced growth responses in maize.
Across both independent experiments, MP exposure reduced shoot and root biomass, photosynthetic capacity, and carbon and nitrogen accumulation, with PP causing more negative effects than PE. Compared with the control, MP exposure decreased shoot Ca, K, Mg, Mn, and S concentrations by 7.5%–44.5%, 5.7%–21.1%, 19.5%–53.4%, 8.6%–39.1%, and 7.1%–26.3%, respectively. Shoot Cu was reduced by 9.8%–47.1%, whereas P decreased by 1.3%–11.8% depending on polymer type and dose. In contrast, shoot Zn increased markedly by 183.0%–322.6% under MP exposure. With a few exceptions, the patterns for root ionomes were generally similar to those of shoots, with reductions of nutrient uptake becoming more pronounced at higher MP doses. These changes led to severe ionic imbalances, which were evidenced by changes in elemental ratios like K:Ca and Zn:Fe, indicating disturbed nutrient homeostasis. Increasing MP concentrations increased membrane damage, as demonstrated by elevated electrolyte leakage and malondialdehyde concentrations, and reduced leaf water content, indicating enhanced oxidative and dehydration stress.
Overall, MP toxicity exerted direct negative effects on maize growth, photosynthesis, and nutritional composition depending on polymer types and concentrations.
Rana Roy, Karl H. Mühling· Journal of Plant Nutrition A...· 0 citations
Polyethylene (PE) microplastics (MPs) are the predominant MP pollutants in agricultural soil ecosystems. To investigate the underlying mechanisms associated with high-load exposure, a controlled pot experiment was conducted to evaluate the effects of pristine PE MPs (1%, 2%, and 3% w/w, ∼100 μm) on soil physicochemical properties, enzyme activities, bacterial communities, and metabolomic profiles in broomcorn millet-planted (P) and unplanted (NP) soils. The results showed that PE treatment significantly increased soil organic matter and inorganic nitrogen content in a dose-dependent manner, while inhibiting enzymes involved in carbon cycling. PE treatment significantly increased Shannon diversity in P soil by 4.1%-4.5% (p < 0.05), whereas network analysis revealed that PE treatment reduced overall co-occurrence connectivity (e.g., the M2 network exhibited the lowest average degree). In P soil, PE treatments (2%-3%) significantly increased the relative abundances of Lysobacter, Sphingomonas, Altererythrobacter, and Flavisolibacter. Metabolomic profiling revealed that PE treatment induced 686 differentially abundant metabolites in NP soil compared to 404 in P soil. PE primarily influenced lipid metabolism in NP soils, whereas carbohydrate-related pathways were more prominent in P soils. Mantel tests and structural equation modeling (SEM) analyses suggested that soil enzyme activity was associated with nutrient availability, microbial biomass, bacterial community structure, and specific metabolites. This study elucidated the mechanistic responses of soil metabolism to high-load pristine MP exposure and highlights plant presence as an important contextual factor for interpreting MP-induced changes.
Miaomiao Zhang, Hai-Qiang Wang, Yani Huang et al.· Ecotoxicology and Environmen...· 0 citations
The co-occurrence of microplastics (MPs) and heavy metals in agricultural ecosystems poses emerging threats, yet their combined ecotoxicological effects on crop plants remain poorly understood. To address this gap, a hydroponic exposure experiment was conducted to evaluate the individual and combined effects of 50 mg·L−1 polystyrene (PS) microplastics, lead (Pb, 35 mg·L−1), and cadmium (Cd, 20 mg·L−1) on the phenotypic growth, biomass accumulation, and peroxidase (POD) activity of rice seedlings. The results indicated that: (1) Individual polystyrene microplastics (PS-MPs) treatment did not induce morphological inhibition; rather, it exhibited a growth-promoting trend, with a significant increase in fresh weight and a non-significant increasing trend in dry weight compared to the control. (2) The phenotypic impact of PS-MPs on the toxicity of heavy metals was element-specific. In the PS + Cd co-exposure system, microplastics significantly alleviated Cd-induced inhibition of fresh weight relative to the single Cd treatment, although this recovery effect was not observed in dry weight. Conversely, in the PS + Pb system, microplastics aggravated the phenotypic toxicity of Pb, with biomass showing a numerical decrease relative to the single Pb treatment, though the difference did not reach statistical significance. (3) The plant antioxidant system exhibited organ-specific responses to the combined stresses. Under PS + Pb co-exposure, root POD activity was significantly up-regulated while shoot POD activity was notably suppressed, revealing an asynchrony in physiological responses between roots and shoots. In contrast, the decrease in root POD activity under the PS + Cd system was consistent with phenotypic recovery in fresh weight. In conclusion, PS-MPs can significantly alter the phenotypic and physiological responses of rice seedlings to heavy metals, with the direction of modulation being element-specific. While the underlying mechanisms require further elucidation, this study provides a phenotypic and physiological basis for assessing the early ecological risks associated with the co-exposure of microplastics and heavy metals.
Zi-Wen Hao, Xiaolu Bie, Pu Niu et al.· Nanomaterials· 0 citations
Microplastics (MPs) are increasingly accumulating in agricultural soils, while their effects on crop-associated rhizosphere microbial communities and ecological functions remain insufficiently understood, particularly for different polymer types. In this study, polyethylene (PE) and polystyrene (PS) microplastics with the same particle size (2 μm) were applied at different concentrations (0, 0.1%, 0.5%, 1%, and 5%, w/w) to investigate their effects on oat rhizosphere bacterial communities and predicted functional potentials. The results showed that microplastic addition significantly altered bacterial community diversity, composition, and predicted functional profiles. Compared to the control (Ctrl), the 1% PE treatment significantly reduced bacterial richness-related indices (p < 0.05), whereas PS mainly affected bacterial diversity. Microplastic treatments also reshaped dominant bacterial taxa and altered the predicted functional potentials associated with carbon and nitrogen cycling. In particular, the 1% PE treatment significantly reduced the predicted relative abundance of the carbon fixation-related gene cbbL (p < 0.05). In addition, high-concentration (5%) PE enhanced several predicted functional potentials related to nitrogen cycling, including nifH, ureA, and amoC. Overall, PE and PS microplastics induced polymer- and concentration-dependent changes in oat rhizosphere bacterial communities. These findings suggest that microplastic accumulation in agricultural soils may influence ecosystem processes by modifying microbial diversity and potential biogeochemical functions. This study provides new insights into the ecological consequences of different microplastic polymers in crop rhizosphere ecosystems and highlights the importance of considering polymer-specific effects when evaluating soil microplastic pollution.
The quality and leaf yield of Passiflora edulis Sims depend on agricultural management decisions that modulate growth, metabolite accumulation, and antioxidant responses. We compared three commercial agroecosystems in Paty do Alferes, Rio de Janeiro (conventional, organic, and agroforestry), quantifying vegetative growth, leaf biomass, secondary metabolites (total flavonoids and total phenolics), and functional markers (ABTS, DPPH, FRAP). A two-factor analysis of variance was applied to assess agroecosystem and temporal effects. Conventional cultivation exhibited the highest vegetative growth and biomass at 20 weeks after planting (1053.3 g fresh mass/plant; 207.8 g dry mass/plant). In contrast, the agroforestry system showed the highest mean flavonoid content (40.3 ± 4.3 mg RE g-1), followed by the organic (33.3 ± 3.01 mg RE g-1) and conventional systems (19.7 ± 2.51 mg RE g-1). Antioxidant activity varied across markers: FRAP values were greatest in the conventional (392.27 ± 33.84 µmol Trolox g-1), intermediate in the organic (357.79 ± 33.07 µmol Trolox g-1), and lowest in the agroforestry system (286.67 ± 15.79 µmol Trolox g-1). ABTS activity was numerically highest under conventional management (116.50, 91.81, and 88.71 µmol Trolox g-1 for conventional, organic, and agroforestry, respectively), and DPPH and total phenolics did not differ significantly among systems overall. These results indicate contrasting production profiles: conventional management favored leaf biomass and FRAP activity, whereas agroforestry favored flavonoid concentration per unit extract; the mechanisms underlying this inverse association were not experimentally resolved.
Stephano Francisco Duarte de Carvalho, Davyson de Lima Moreira, Leilson de Oliveira Ribeiro et al.· Agroforestry Systems· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
