Naphthalen-1-yl 2,4,6-trimethyl benzenesulfonate enhances cadmium tolerance in Zea mays by boosting antioxidant defense and photosynthetic efficiency

Abstract

Cadmium (Cd) contamination in agricultural soils is a serious environmental issue that reduces crop yield and threatens food safety and human health. While conventional chelators enhance Cd uptake, they often impair plant health. This study investigates whether naphthalene-1-yl 2,4,6-trimethyl benzenesulfonate (NTB) acts as a dual-functional agent by enhancing Cd uptake and reducing toxicity in maize. Maize seedlings pretreated with 0.25 mM NTB and exposed to 100 mu M CdCl2 showed a 69% increase in Cd accumulation. NTB reduced oxidative stress, lowering TBARS and H2O2 levels by 37% and 34%, respectively. Proline accumulation rose by only 12%, and RWC increased by 9%, indicating improved stress tolerance. Antioxidant enzyme responses shifted: SOD activity declined by 71%, while CAT, APX, and GPX decreased by 24%, 19%, and 37%. NTB also elevated antioxidants, including gallic acid (61%), epicatechin (71%), vanillic acid (42%), and rosmarinic acid (64%). Total chlorophyll increased by 68%, and gas exchange parameters improved: Pn by 70%, Tr by 46%, gs by 14%, and Ci by 72%. Fluorescence parameters also improved, with Fv/Fm and Phi PSII increasing by 19% and 14%, and NPQ decreasing by 14%. These results show that NTB enhances Cd uptake while maintaining physiological balance, offering a promising phytoremediation strategy.