Abstract

In this study, ten different plant leaves were collected from different urban microenvironments in the Hyderabad metropolitan area to assess their potential as bioindicators of air pollution. The collected leaf samples were analysed for surface PM accumulation, total chlorophyll concentration, carotenoid content, ascorbic acid, leaf extract pH, relative water content, and air pollution tolerance index (APTI). Out of ten plants, Ficus religiosa, which is located near the roadside, showed the highest PM accumulation with 54 µg/cm2. Tecoma stans showed the highest APTI value of 7.45 and ascorbic acid content of 10 mg/g, exhibiting greater tolerance to pollution, as well as potential for urban greening and air quality enhancement. Senegalia caesia with low APTI showed excellent carotenoid concentration of 19.42 mg/g, indicating that the plant is pollutant-sensitive, but activates antioxidant defence in response to oxidative stress. Hierarchical clustering analysis revealed a decent grouping of plant species based on biochemical profiles, validating stress tolerance patterns and PM deposition. The study highlights how pollutant deposition is linked to plant health and suggests that plants with adaptive leaf traits are more capable of tolerating polluted conditions. The findings of the study suggest that sensitive plants like Senegalia caesia, Lantana camara L., can serve as effective bioindicators and passive monitors of pollution levels and urban greening initiatives, and tolerant plants like Wodyetia bifurcata and Tecoma stans may contribute to a sustainable solution for mitigating urban air quality and supporting long-term environmental planning in polluted urban ecosystems.