Phytotoxic impact of di-butyl phthalate (DBP) on physiological, biochemical, and oxidative stress parameters of rice (Oryza sativa).

Phthalates are synthetic compounds, well-known plasticizers, with numerous applications and reported to have adverse effects on all living organisms residing in terrestrial and aquatic environments. In this study, the rice (Oryza sativa) seedlings were exposed to di-butyl phthalate (DBP) exogenously for 7 days, with varying concentrations of 0, 200, 400, 800, and 1600 mg/L, to explore the toxicological, physiological, and biochemical consequences by measuring various parameters such as pigment, lipid, and HO (hydrogen peroxide) contents. The biochemical analysis of seedlings showed that the pigments, lipids, and HO concentrations were altered abnormally. After 7 days of exposure, the maximum amount of DBP was accumulated and translocated in both the shoot and root of the grown seedlings, and all morphological parameters (i.e., length and weight of both shoot and root) and pigment content (such as total carotenoid, chlorophyll a and b) were declined significantly. Superoxide dismutase (SOD), HO, and thiobarbituric acid reactive substance (TBARS) levels in seedlings increase as the stress increases due to the higher exposure dose of DBP. Cell viability was observed under a confocal microscope confirming the damage of the plasma membrane. Additionally, molecular docking studies indicated that DBP has a good binding affinity with key antioxidant enzymes of Oryza sativa, interacting via hydrogen bonds with specific amino acids. This suggests a potential mechanistic pathway for the observed biochemical changes in Oryza sativa.