State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
Sci Total Environ. 2024 Dec 10;955:176734. doi: 10.1016/j.scitotenv.2024.176734. Epub 2024 Oct 9.
Weakly alkaline cadmium (Cd) contaminated soil in China has aroused great concern regarding its impact on food security and human health. Mercapto-modified palygorskite (MP) has exhibited good potential to minimize Cd accumulation in wheat, it is imperative to understand the underlying mechanisms within the soil-wheat-microbial system for sustainable development of agrochemicals. This study evaluated the effects of various MP dosages on soil Cd bioavailability, rhizosphere metabolomics, microbial community structure and wheat growth. The results indicated that MP (0.05-0.2 %) application significantly reduced Cd accumulation in wheat grains by 59.0-83.2 % (p < 0.05) and inhibited Cd translocation from root to grain. MP also promoted Mn oxide formation and redistributed the exchangeable Cd to Fe-Mn oxide-bound forms (44.2-109.6 %), thus lowering soil Cd bioavailability by 17.9-32.5 %. Additionally, MP reduced wheat rhizosphere organic acid levels, altered rhizosphere carbon and nitrogen pools, and stimulated the growth of Cd-tolerant Alternaria and Cladosporium, while inhibiting the growth of Fusarium. These findings highlight the potential of MP to modulate soil rhizosphere metabolism and microbial communities, offering a novel perspective on its environmental implications and supporting agrochemical sustainability.
中国弱碱性镉（Cd）污染土壤对食品安全和人类健康的影响引起了极大关注。巯基改性坡缕石（MP）已被证明在降低小麦中 Cd 积累方面具有良好的潜力，了解土壤-小麦-微生物系统中的潜在机制对于农用化学品的可持续发展至关重要。本研究评估了不同 MP 剂量对土壤 Cd 生物有效性、根际代谢组学、微生物群落结构和小麦生长的影响。结果表明，MP（0.05-0.2%）的应用显著降低了小麦籽粒中 Cd 的积累，降幅为 59.0-83.2%（p<0.05），并抑制了 Cd 从根部向籽粒的转运。MP 还促进了 Mn 氧化物的形成，并将可交换态 Cd 重新分配到 Fe-Mn 氧化物结合态（44.2-109.6%），从而降低了土壤 Cd 的生物有效性 17.9-32.5%。此外，MP 降低了小麦根际有机酸水平，改变了根际碳氮库，并刺激了 Cd 耐受的链格孢和枝孢的生长，同时抑制了镰刀菌的生长。这些发现强调了 MP 调节土壤根际代谢和微生物群落的潜力，为其环境意义提供了新的视角，并支持农用化学品的可持续性。
