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

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 µM 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 ΦPSII 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. NTB is a structurally unique, dual-function phytoremediation agent that simultaneously enhances Cd uptake and protects plant physiology. Its combined chelating and antioxidant properties offer a safer, more effective alternative to conventional agents like EDTA, supporting both contaminant removal and crop health in Cd-polluted soils.

农业土壤中的镉（Cadmium, Cd）污染是一类严重的环境问题，不仅会降低作物产量，还会威胁食品安全与人体健康。传统螯合剂虽可提升作物对镉的吸收效率，但往往会损害植物自身健康。本研究旨在探究萘-1-基2,4,6-三甲基苯磺酸盐（naphthalene-1-yl 2,4,6-trimethyl benzenesulfonate, NTB）是否可作为双功能试剂，在提升玉米对镉吸收量的同时降低其毒性。经0.25 mM NTB预处理并暴露于100 µM CdCl₂的玉米幼苗，其镉积累量提升了69%。NTB可有效缓解氧化应激，使硫代巴比妥酸反应物质（TBARS）与过氧化氢（H₂O₂）水平分别降低37%与34%。脯氨酸积累量仅上升12%，而相对含水量（Relative Water Content, RWC）提升9%，表明植株的胁迫耐受性得到改善。抗氧化酶响应模式发生改变：超氧化物歧化酶（Superoxide Dismutase, SOD）活性下降71%，而过氧化氢酶（Catalase, CAT）、抗坏血酸过氧化物酶（Ascorbate Peroxidase, APX）与谷胱甘肽过氧化物酶（Glutathione Peroxidase, GPX）的活性分别降低24%、19%与37%。NTB同时可提升多种抗氧化成分含量：没食子酸（61%）、表儿茶素（71%）、香草酸（42%）与迷迭香酸（64%）。总叶绿素含量提升68%，气体交换参数亦得到改善：净光合速率（Net Photosynthetic Rate, Pn）上升70%、蒸腾速率（Transpiration Rate, Tr）上升46%、气孔导度（Stomatal Conductance, gs）上升14%，胞间CO₂浓度（Intercellular CO₂ Concentration, Ci）上升72%。叶绿素荧光参数同样得到优化：PSII最大光化学量子效率（Fv/Fm）与实际光化学量子效率（ΦPSII）分别提升19%与14%，而非光化学淬灭（NPQ）下降14%。上述结果表明，NTB可在提升玉米镉吸收量的同时维持植株生理平衡，为镉污染土壤的植物修复提供了极具潜力的策略。NTB是一种结构独特的双功能植物修复试剂，可同时增强镉吸收并保护植株生理健康。其兼具螯合与抗氧化特性，相较于乙二胺四乙酸（Ethylenediaminetetraacetic Acid, EDTA）等传统试剂更为安全高效，可在镉污染农田中同时实现污染物移除与作物健康保障。