Abstract：
Organic matter (OM) accumulation in lake sediments has doubled owing to human activities over the past 100 years, which has negatively affected the restoration of submerged vegetation and ecological security. Changes in the pollution structure of sediments caused by plant recovery and rhizosphere chemical processes under different sediment OM levels are the theoretical basis for the rational application of plant rehabilitation technology in lake management. This study explored how Vallisneria natans mediates changes in sediment N and P through rhizospheric metabolites and microbial community and function under low (4.94 %) and high (17.35 %) sediment OM levels. V. natans promoted the accumulation of NH4-N in the high-OM sediment and the transformation of Fe/Al-P to Ca-P in the low-OM sediment. By analyzing 63 rhizospheric metabolites and the sediment microbial metagenome, the metabolites lactic acid and 3-hydroxybutyric acid and the genus Anammoximicrobium were found to mediate NH4-N accumulation in the high-OM sediment. Additionally, 3-hydroxy-decanoic acid, adipic acid, and the genus Bdellovibrionaceae mediated the transformation of Fe/Al-P to Ca-P in the low-OM sediment. The growth of V. natans enriched the abundance of functional genes mediating each step from nitrate to ammonia and the genes encoding urease in the high-OM sediment, and it up-regulated three genes related to microbial phosphorus uptake in the low-OM sediment. This study revealed the necessity of controlling endogenous pollution by recovering submerged macrophytes under high- and low-OM conditions from the perspective of the transformation of inorganic nitrogen and phosphorus.
摘要：
在过去的100年中，由于人类活动，湖泊沉积物中的有机质（OM）积累增加了一倍。影响了淹没植被的恢复和生态安全。不同沉积物OM水平下植物恢复和根际化学过程引起的沉积物污染结构变化是植物恢复技术在湖泊管理中合理应用的理论基础。这项研究探讨了在低（4.94％）和高（17.35％）沉积物OM水平下，Vallisnianatans如何通过根际代谢产物和微生物群落和功能介导沉积物N和P的变化。V.natans促进了高OM沉积物中NH4-N的积累和低OM沉积物中Fe/Al-P向CaP的转化。通过对63种根际代谢产物和沉积物微生物宏基因组的分析,发现代谢产物乳酸和3-羟基丁酸以及Anammoximicbium属可介导高OM沉积物中NH4-N的积累。此外,3-羟基癸酸,己二酸,Bdellovibrionaceae属介导了低OM沉积物中Fe/Al-P向CaP的转化。在高有机质沉积物中，纳豆弧菌的生长丰富了介导从硝酸盐到氨的每一步的功能基因和编码脲酶的基因的丰度，它上调了低OM沉积物中与微生物磷吸收有关的三个基因。这项研究从无机氮和磷的转化角度揭示了通过在高和低OM条件下恢复沉水植物来控制内源性污染的必要性。
