Fang Wen-Ze, Chen Jun-Qiao, Mao Jing-Dong, Zhang Bao-Feng, Lou Li-Ping, Lin Qi
Key Laboratory of Water Pollution Control and Environmental Safety of Zhejiang Province, Department of Environmental Engineering, Zhejiang University, Zhejiang Province, Hangzhou, 310058, P.R. China.
Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Boulevard, Norfolk, VA, 23529, USA.
Environ Sci Pollut Res Int. 2025 Jan;32(5):2479-2491. doi: 10.1007/s11356-025-35888-5. Epub 2025 Jan 11.
Applying nano-delivery systems for phytohormones via foliar application has proven effective in reducing grain cadmium (Cd) levels in crops. However, the mechanisms underlying this reduction remain inadequately understood. This study integrated the determination of leaf photosynthetic parameters, Cd translocation analysis, and metabolomics to elucidate the effects of reduced glutathione (GSH) and melatonin (MT), delivered with or without chitosan-encapsulated mesoporous silica nanoparticles (MSN-CS), on grain Cd levels in rice. Our findings revealed that the foliar application of MT@MSN-CS significantly outperformed MT alone in reducing grain Cd levels and enhancing leaf photosynthesis under Cd stress. Conversely, GSH@MSN-CS showed comparable effects to GSH alone. Foliar-applied GSH@MSN-CS and MT@MSN-CS both decreased the Cd transport coefficients from panicle nodes to brown rice by 26.2-53.3%, with MT@MSN-CS demonstrating superior efficiency in reducing Cd concentrations across roots, stems, leaves, panicle nodes, and grains. Metabolomic analysis revealed substantial shifts in rice metabolite profiles following GSH@MSN-CS and MT@MSN-CS treatments. Foliar application of MT@MSN-CS or GSH@MSN-CS may rapidly and effectively activate the primary antioxidant defense system and alleviate membrane lipid peroxidation in rice grown on low-to-moderately Cd-contaminated soils by upregulating amino acid metabolism. The secondary defense mechanism, phenylpropanoid biosynthesis, was reprogrammed to reduce energy expenditure and decrease Cd translocation.
通过叶面喷施应用纳米递送系统来输送植物激素已被证明在降低作物籽粒镉（Cd）含量方面是有效的。然而，这种降低背后的机制仍未得到充分理解。本研究综合测定叶片光合参数、镉转运分析和代谢组学，以阐明还原型谷胱甘肽（GSH）和褪黑素（MT）在有或没有壳聚糖包裹的介孔二氧化硅纳米颗粒（MSN-CS）递送情况下对水稻籽粒镉含量的影响。我们的研究结果表明，在镉胁迫下，叶面喷施MT@MSN-CS在降低籽粒镉含量和增强叶片光合作用方面显著优于单独喷施MT。相反，GSH@MSN-CS与单独喷施GSH表现出相当的效果。叶面喷施GSH@MSN-CS和MT@MSN-CS均使从穗节到糙米的镉转运系数降低了26.2-53.3%，其中MT@MSN-CS在降低根、茎、叶、穗节和籽粒中的镉浓度方面效率更高。代谢组学分析显示，在GSH@MSN-CS和MT@MSN-CS处理后，水稻代谢物谱发生了显著变化。叶面喷施MT@MSN-CS或GSH@MSN-CS可能通过上调氨基酸代谢，快速有效地激活水稻在低至中度镉污染土壤上生长时的主要抗氧化防御系统，并减轻膜脂过氧化。次生防御机制苯丙烷类生物合成被重新编程，以减少能量消耗并减少镉的转运。
