Effect of Microplastics on the Germination and Growth of Terrestrial Plants

Objectives : The human beings of our globe are heavily reliant on the use of plastic products on a daily basis. Microplastics (MPs) are tiny particles that are formed as a result of plastic degradation. MPs can be found in terrestrial environment, but previous studies focused on the effects of MPs on marine environment and there are less studies on the effects of MPs on terrestrial environment. In particular, there is still a relatively limited number of studies on the effects of MPs on terrestrial plants. Therefore, this review paper aims to examine previous studies on the effect of MPs on the germination and growth of terrestrial plants.Methods : This review summarized the previous findings on the effect of MPs on the germination and growth of terrestrial plants in order to identify the research gaps and trends on the effects of MPs on terrestrial plants.Results and Discussion : Previous studies on the effect of MPs on the germination and growth of terrestrial plants were reviewed and the observations were summarized to find the gaps in this field of research. Previous studies showed that MPs can change soil properties and these changes can be different depending on the shape and size of MPs. MPs can also release chemicals such as phthalates and heavy metals that might have toxic effects on terrestrial plants. Different forms, types, and sizes of MPs were used in previous studies to study the effects on seed germination and growth of different plants. Most studies reported that MPs have negative effects on seed germination and plant growth (e.g., biomass, chlorophyll contents). Smaller MPs tend to have more significant effects than larger MPs. The changes in the soil properties due to MPs can change microbial community structures and this, in turn, may affect the soil-plant interaction.Conclusion : This study summarizes what have been reported in the previous studies on the effect of MPs on seed germination and growth of terrestrial plants. MPs are likely to affect seed germination and plant growth negatively, and this will eventually lead to reduction in food production and food quality. Owing to the various types, forms, and sizes of MPs that could be present in the terrestrial environment as well as the chemicals that could be released from MPs, there is much to explore to better understand the effect of MPs on terrestrial plants and the underlying mechanisms of such effects.