Assessment of physiological stress on plants grown in soil contaminated with microplastics

The current study was conducted with the aim to analyze the effect of microplastics on vegetable plants i.e., Spring Onion and Okra. Three types of microplastics sources were used i.e., Transparent plastic Bottles (Polyethylene terephthalate) (PET); transparent plastic bags (High-density polyethylene) (HDPE) and Polyester fiber (100% Polyester) (PES). Each type of plastic was mechanically/manually shredded to an approximate size of 4 mm and subsequently incorporated into soil at a concentration of 1% w/w. Control groups without microplastic addition were also established for comparison. Germinated seeds of spring onion and okra were sown in each experimental setup and plants were monitored and analyzed for morphological characteristics, oxidative stress indicators, and pigment content, including chlorophyll and carotenoids. The findings revealed that microplastic exposure had a statistically significant effect on plant health and development. Among the three microplastic types, PET induced the least detrimental effects, while HDPE and PES exhibited more pronounced impacts. All microplastic treatments led to a decrease in chlorophyll and carotenoid levels, alongside an increase in reactive oxygen species (ROS) production and lipid peroxidation, indicative of heightened oxidative stress. Additionally, reductions in key morphological parameters such as plant height, leaf number, and biomass were observed. Results of the study underscores the potential ecological risks posed by microplastic contamination in soil, highlighting its capacity to adversely affect plant physiology and development. Therefore, emphasizes the urgent need for strategies to mitigate microplastic pollution in terrestrial ecosystems.