韦革宏、陈春等《Environmental Science & Technology》2023年

论文题目：Pristine and Sulfidized Zinc Oxide Nanoparticles Promote the Release and Decomposition of Organic Carbon in the Legume Rhizosphere

论文作者：Lin Liu，Olga V. Tsyusko，Jason M. Unrine，Shuang Liu，Yidan Liu，Lulu Guo，Gehong Wei*，and Chun Chen*

论文摘要：The effects and mechanisms of zinc oxide nanoparticles (ZnO NPs) and their aging products, sulfidized (s-) ZnO NPs, on the carbon cycling in the legume rhizosphere are still unclear. We observed that, after 30 days of cultivation, in the rhizosphere soil of Medicago truncatula, under ZnO NP and s-ZnO NP treatments, the dissolved organic carbon (DOC) concentrations were significantly increased by 1.8- to 2.4-fold compared to Zn2+ treatments, although the soil organic matter (SOM) contents did not change significantly. Compared to Zn2+ additions, the additions of NPs significantly induced the production of root metabolites such as carboxylic acids and amino acids and also stimulated the growth of microbes involved in the degradations of plant-derived and recalcitrant SOM, such as bacteria genera RB41 and Bryobacter, and fungi genus Conocybe. The bacterial co-occurrence networks indicated that microbes associated with SOM formation and decomposition were significantly increased under NP treatments. The adsorption of NPs by roots, the generation of root metabolites (e.g., carboxylic acid and amino acid), and enrichment of key taxa (e.g., RB41 and Gaiella) were the major mechanisms by which ZnO NPs and s-ZnO NPs drove DOC release and SOM decomposition in the rhizosphere. These results provide new perspectives on the effect of ZnO NPs on agroecosystem functions in soil–plant systems.

氧化锌纳米颗粒（ZnO NPs）及其老化产物硫化锌（s-ZnO NPs）对豆科植物根际碳周转的影响及其机制尚不清楚。结果表明，在种植苜蓿30天后的根际土壤中，与Zn2+处理相比，ZnO NPs和s-ZnO NPs处理显著增加了溶解性有机碳（DOC）浓度约1.8 ~ 2.4倍，然而土壤有机质（SOM）含量没有显著变化。与Zn2+处理相比，施加NPs显著促进了根代谢物（如羧酸和氨基酸）的产生，并刺激了参与植物源和难降解SOM分解的微生物的生长，如细菌属RB41、Bryobacter和真菌属Conocybe。共发生网络分析表明，在NPs处理中，与SOM形成和分解相关的微生物增加了。根系对NPs的吸附、根代谢物（如羧酸和氨基酸）的产成以及关键类群（如RB41和Gaiella）的富集是ZnO NPs和s-ZnO NPs驱动根际DOC释放和SOM分解的主要机制。这些结果为理解土壤-植物体系中ZnO NPs对农田生态系统功能的影响提供了新的视角。

论文链接：https://pubs.acs.org/doi/10.1021/acs.est.3c02071