Cement Dust Stress and Biochemical Responses in Eucalyptus globulus L.

Abstract

Cement dust pollution poses a significant threat to plant health by altering physiological and biochemical processes. This study investigated the impact of cement dust on Eucalyptus plants collected from three sites, focusing on pigment content, oxidative stress indicators, antioxidant responses, osmolyte accumulation, phenolic compounds, and lipid metabolism. Results showed a marked reduction in chlorophyll (a, b), total chlorophyll, carotenoids, and lycopene, particularly at the most polluted site (S2), indicating impaired photosynthetic capacity. Lipid peroxidation, assessed through thiobarbituric acid reactive substances (TBARS) levels, significantly increased in polluted sites, highlighting oxidative stress. Antioxidant enzyme activities, including guaiacol peroxidase (GPX), catalase (CAT), and ascorbate peroxidase (APX), were elevated, whereas superoxide dismutase (SOD) activity declined. Total soluble sugar (TSS) accumulation increased, particularly at S2, whereas proline content decreased at both polluted sites. Phenolic and flavonoid contents were highest in S1 and S2, respectively, correlating with enhanced antioxidant activity (DPPH and ABTS assays). Additionally, total lipid yield significantly increased at S2, while chlorophyll and beta-carotene contents in Eucalyptus leaf oil decreased under pollution stress. These findings suggest that Eucalyptus plants undergo significant biochemical and physiological adjustments to mitigate the adverse effects of cement dust pollution. Understanding these responses can inform environmental monitoring and mitigation strategies in industrial areas.