Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science & Technology, Xinjiang University, Urumqi, Xinjiang 830046, PR China.
Key Laboratory of Oasis Eco-agriculture, Xinjiang Production and Construction Corps, Agricultural College, Shihezi University, Shihezi, Xinjiang 832000, PR China.
Ecotoxicol Environ Saf. 2023 Oct 1;264:115463. doi: 10.1016/j.ecoenv.2023.115463. Epub 2023 Sep 13.
Polymer materials have great potential for soil heavy metal contamination remediation, but the metabolic mechanism by which polymer amendments regulate the responses of soil-plant systems to cadmium (Cd) stress is still unclear. To clarify the metabolic mechanism by which a self-developed soluble polymer amendment (PA) remediates Cd contamination in cotton fields, the common and differential metabolites in soil and cotton leaves were analyzed during the critical period of cotton growth (flowering and bolling stage) in a field experiment. The results showed that Cd stress increased Cd concentration in the soil-cotton system, and reduced enzyme activity in soil and cotton leaves. Besides, Cd stress also reduced the abundance of α-linolenic acid in soil and the abundance of 2-Oxoarginine and S-Adenosylmethionine in cotton leaves. These ultimately led to reductions in weight, boll number, yield, and fiber elongation. However, the application of PA to the Cd-contaminated soil significantly reduced the soil exchangeable Cd (Ex-Cd) concentration by 41.43%, and increased the boll number, yield, and fiber strength by 14.17%, 21.04%, and 19.89%, respectively compared with the Cd treatment. The results of metabolomic analysis showed that PA application mainly affected the Nicotinate and nicotinamide metabolism pathway, Lysine degradation pathway, and Arginine and proline metabolism pathway in cotton leaves and soil. Besides, in these metabolic pathways, succinic acid semialdehyde of cotton leaves, saccharopine of soil, and S-Adenosylmethionine of soil and cotton had the most significant response to PA application. Therefore, the application of PA to Cd-contaminated soil can increase soil and cotton leaf enzyme activity and cotton yield (boll number and seed cotton yield) and quality (fiber strength), and maintain soil-plant material balance by regulating the distribution of Cd ions and key metabolites in the soil-cotton system. This study will deepen our understanding of the metabolic mechanism of PA remediating Cd-contaminated cotton fields, and provide a technical reference for the remediation of heavy metal contamination in drip-irrigated cotton fields in arid areas.
高分子材料在土壤重金属污染修复方面具有巨大潜力，但高分子改良剂调控土壤-植物系统对镉（Cd）胁迫响应的代谢机制尚不清楚。为阐明自主研发的水溶性高分子改良剂（PA）修复棉田 Cd 污染的代谢机制，在田间试验中，于棉花生长关键期（花铃期）分析了土壤和棉叶中的共有和差异代谢物。结果表明，Cd 胁迫增加了土壤-棉系统中 Cd 浓度，降低了土壤和棉叶中酶活性。此外，Cd 胁迫还降低了土壤中α-亚麻酸的丰度和棉叶中 2-氧代精氨酸和 S-腺苷甲硫氨酸的丰度，进而导致棉株生物量、铃数、产量和纤维伸长率降低。然而，将 PA 施加到 Cd 污染土壤中可使土壤可交换态 Cd（Ex-Cd）浓度降低 41.43%，并分别使铃数、产量和纤维强度增加 14.17%、21.04%和 19.89%。代谢组学分析结果表明，PA 主要影响棉叶和土壤中的烟酸和烟酰胺代谢途径、赖氨酸降解途径以及精氨酸和脯氨酸代谢途径。此外，在这些代谢途径中，棉叶中的琥珀酸半醛、土壤中的蔗糖、以及土壤和棉叶中的 S-腺苷甲硫氨酸对 PA 的响应最显著。因此，将 PA 施加到 Cd 污染土壤中可以通过调节土壤-棉系统中 Cd 离子和关键代谢物的分布，增加土壤和棉叶酶活性及棉花产量（铃数和皮棉产量）和品质（纤维强度），维持土壤-植物物质平衡。该研究将深化我们对 PA 修复 Cd 污染棉田的代谢机制的认识，并为干旱区滴灌棉田重金属污染修复提供技术参考。
