Microplastics: Effects on Plant Health
Following our previous blog post where we described the influence of microplastics on soil health, it is important to examine how these particles directly affect plants. While soil acts as the main reservoir, plants represent the biological interface through which microplastics can influence crop performance and enter the food chain. Recent research shows that microplastics are not only present in soil systems but are actively taken up by plants, where they can affect physiological, biochemical, and molecular processes (1).
Uptake and Translocation in Plants
Microplastics can enter plants through both root and foliar pathways. Root uptake occurs when particles adhere to root surfaces and penetrate tissues, particularly through cracks or natural openings. Studies have shown that particles as small as 0.2 μm and even nanoplastics (<100 nm) can enter roots and move to aboveground tissues via the transpiration stream. For example, polystyrene particles have been detected in wheat and lettuce, accumulating in roots, stems, and leaves (2). In addition to root uptake, foliar absorption plays a role. Microplastics deposited on leaves can enter through stomata, which are typically 3 to 10 μm wide. Once inside, they can move through the vascular system, initially accumulating near stomata before being transported to stems and even back toward roots. This demonstrates that microplastics can circulate within plant systems and are not restricted to the point of entry (3).
Effects on Plant Growth and Development
Microplastic exposure significantly affects plant growth parameters, particularly root development. Studies report reductions in root length, biomass, and overall plant growth. For instance, exposure to microplastics has been shown to decrease root biomass in Phaseolus vulgaris under increasing concentrations, indicating a dose-dependent response. Similarly, wheat exposed to low-density polyethylene (LDPE) and Arabidopsis exposed to polystyrene nanoparticles showed inhibited root and shoot growth (4). In some cases, plants may exhibit increased root growth under specific concentrations of microplastics, such as Lepidium sativum exposed to nanoscale particles (5). However, this response is generally interpreted as a stress adaptation mechanism rather than a beneficial effect, as it is often accompanied by negative impacts on shoot development and overall plant health. At the cellular level, microplastics induce oxidative stress, which is a key mechanism of toxicity. Exposure leads to excessive production of reactive oxygen species (ROS), overwhelming antioxidant defense systems. This results in lipid peroxidation, damage to cellular membranes, and disruption of metabolic processes. For example, studies on Vicia faba have shown increased activity of stress-related enzymes such as superoxide dismutase (SOD) and peroxidase (POD), alongside reduced catalase activity, indicating oxidative imbalance. These biochemical changes are associated with reduced cell division and impaired root development (6).
Impact on Photosynthesis
Photosynthesis is highly sensitive to microplastic-induced stress. Exposure has been linked to reduced chlorophyll content and decreased photosynthetic efficiency. In some plant species, such as macrophytes exposed to PVC microplastics, significant reductions in chlorophyll content and fluorescence have been observed. These effects are associated with oxidative damage and disruption of internal transport systems, leading to reduced energy production and lower biomass accumulation. As photosynthesis is directly linked to crop productivity, these changes have important implications for agricultural yields (7).
Molecular and Genetic Responses
Microplastics also affect plants at the molecular level by altering gene expression and regulatory pathways. Studies indicate that exposure can suppress genes involved in plant defense and growth regulation, while also affecting hormone-related pathways. For instance, in Allium cepa, microplastic exposure has been associated with chromosomal abnormalities and reduced expression of cell cycle-related genes such as cdc2 (8). These findings highlight the potential for genotoxic effects and long-term impacts on plant development.
Microplastics as Vectors of Contaminants
Microplastics can act as carriers for other environmental contaminants due to their large surface area and chemical properties. They can adsorb heavy metals, persistent organic pollutants, and pathogens, which may then be transported into plant tissues upon uptake. This vector effect increases the ecological risk associated with microplastics, as it facilitates the movement of multiple pollutants through the soil-plant system and enhances their bioavailability (9).
Implications for Agriculture and Food Safety
The accumulation of microplastics in plant tissues has direct implications for agriculture and food systems. Reduced plant growth, impaired physiological processes, and decreased photosynthetic efficiency can negatively impact crop productivity. More importantly, the presence of microplastics in edible plant parts suggests a pathway for their entry into the human food chain. Studies have confirmed that microplastics can accumulate in fruits, stems, and leaves, raising concerns about food safety and long-term exposure. Within this context, the InPlasTwin project directly addresses these emerging challenges. The project focuses on advancing knowledge and analytical capacity related to micro- and nanoplastics in agricultural systems. A key component of this work is the investigation of how these particles affect crop plants, with a particular focus on strawberries as a model crop. Strawberries are especially relevant due to their direct consumption and economic importance, making them a critical case for understanding food safety risks. By studying the uptake, accumulation, and physiological effects of microplastics in strawberries, InPlasTwin aims to generate evidence on how contamination translates from soil to edible plant tissues. This research will contribute to assessing potential risks for consumers, while also supporting the development of more sustainable agricultural practices and mitigation strategies.
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References
- Chaudhary, H. D., Shah, G., Bhatt, U., Singh, H., & Soni, V. (2025). Microplastics and plant health: a comprehensive review of sources, distribution, toxicity, and remediation. npj Emerging Contaminants, 1(1), 8.
- Conti, G. O., Ferrante, M., Banni, M., Favara, C., Nicolosi, I., Cristaldi, A., … & Zuccarello, P. (2020). Micro-and nano-plastics in edible fruit and vegetables. The first diet risks assessment for the general population. Environmental research, 187, 109677.
- Sun, H., Lei, C., Xu, J. & Li, R. Foliar uptake and leaf-to-root translocation of nanoplastics with different coating charge in maize plants. J. Hazard Mater. 416, 125854 (2021)
- Sun, X.-D. et al. Differentially charged nanoplastics demonstrate distinct accumulation in Arabidopsis thaliana. Nat. Nanotechnol. 15, 755–760 (2020).
- Bosker, T., Bouwman, L. J., Brun, N. R., Behrens, P. & Vijver, M. G. Microplastics accumulate on pores in seed capsule and delay germination and root growth of the terrestrial vascular plant Lepidium sativum. Chemosphere 226, 774–781 (2019).
- Jiang, X., Chen, H., Liao, Y., Ye, Z., Li, M., & Klobučar, G. (2019). Ecotoxicity and genotoxicity of polystyrene microplastics on higher plant Vicia faba. Environmental Pollution, 250, 831-838.
- Colzi, I., Renna, L., Bianchi, E., Castellani, M. B., Coppi, A., Pignattelli, S., … & Gonnelli, C. (2022). Impact of microplastics on growth, photosynthesis and essential elements in Cucurbita pepo L. Journal of Hazardous Materials, 423, 127238.
- Maity, S., Chatterjee, A., Guchhait, R., De, S. & Pramanick, K. Cytogenotoxic potential of a hazardous material, polystyrene microparticles on Allium cepa L. J. HazardMater. 385, 121560
- Fajardo, C., Martín, C., Costa, G., Sánchez-Fortún, S., Rodríguez, C., de Lucas Burneo, J. J., … & Martín, M. (2022). Assessing the role of polyethylene microplastics as a vector for organic pollutants in soil: Ecotoxicological and molecular approaches. Chemosphere, 288, 132460.
