School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China; Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Affairs, Shanghai, 200240, China; Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, Ministry of Science and Technology, Ministry of Education, Shanghai, 200240, China; Shanghai Urban Forest Ecosystem Research Station, National Forestry and Grassland Administration, Shanghai, 200240, China; Bor S. Luh Food Safety Research Center, Shanghai, 200240, China; Yunnan Dali Research Institute, Shanghai Jiaotong University, Shanghai, 200240, China.
School of Agriculture and Biology, Shanghai Jiaotong University, Shanghai, 200240, China; Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Affairs, Shanghai, 200240, China; Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station, Ministry of Science and Technology, Ministry of Education, Shanghai, 200240, China; Shanghai Urban Forest Ecosystem Research Station, National Forestry and Grassland Administration, Shanghai, 200240, China; Bor S. Luh Food Safety Research Center, Shanghai, 200240, China; Yunnan Dali Research Institute, Shanghai Jiaotong University, Shanghai, 200240, China.
J Environ Manage. 2024 Oct;369:122206. doi: 10.1016/j.jenvman.2024.122206. Epub 2024 Aug 27.
Endophyte assisted phytoremediation of cadmium (Cd) contaminated soil represents a promising strategy. However, the precise soil ecological regulatory mechanisms by which endophyte enhance the Cd phytoextraction remain unclear. Here, we employed the plant growth promoting endophyte (PGPE) Pseudomonas sp. E3, which has been validated to effectively enhance Cd extraction in Solanum nigrum L., to investigate its regulatory mechanism on soil ecology. The results demonstrated that while PGPE inoculation resulted in minimal alterations to the physicochemical properties of the bulk soil, it led to a notable increase in acid phosphatase activity by 17.86% and urease activity by 24.85% in the rhizosphere soil. This, in turn, significantly raised the available nitrogen and phosphorus contents by 16.93% and 21.27%, respectively, in the rhizosphere soil. Additionally, PGPE inoculation effectively replenished the bioavailable fractions of Fe and Cd, which had been depleted due to root uptake. Importantly, the inoculation specifically augmented the abundance of biomarkers p_Patescibacteria, f_Saccharimonadales, and g_Saccharimonadales in the rhizosphere soil. These biomarkers exhibited a significant positive correlation with the available nutrient and metal element contents. Moreover, the co-occurrence network analysis demonstrated that the inoculation resulted in a simplified bacterial community network, which may have facilitated community synergism by displacing bacteria with a negative association. This regulation appears to occur independently of PGPE colonization. Overall, our findings suggested that PGPE also exerts a regulatory influence on soil ecological features, significantly aiding hyperaccumulators in nutrient acquisition and heavy metal accumulation.
内生菌辅助修复镉（Cd）污染土壤是一种很有前途的策略。然而，内生菌增强植物提取 Cd 的精确土壤生态调控机制仍不清楚。在这里，我们采用已被证实可有效增强龙葵 Cd 提取的植物促生内生菌（PGPE）假单胞菌 E3，来研究其对土壤生态的调控机制。结果表明，虽然 PGPE 接种对土壤的物理化学性质几乎没有改变，但在根际土壤中，酸磷酸酶活性显著增加了 17.86%，脲酶活性增加了 24.85%。这反过来又使根际土壤中的有效氮和有效磷含量分别显著提高了 16.93%和 21.27%。此外，PGPE 接种有效地补充了因根系吸收而耗尽的可利用 Fe 和 Cd 生物有效分数。重要的是，接种特别增加了根际土壤中 p_Patescibacteria、f_Saccharimonadales 和 g_Saccharimonadales 的生物标志物丰度。这些生物标志物与有效养分和金属元素含量呈显著正相关。此外，共同发生网络分析表明，接种导致细菌群落网络简化，这可能通过取代具有负相关关系的细菌来促进群落协同作用。这种调节似乎独立于 PGPE 的定殖。总的来说，我们的研究结果表明，内生菌也对土壤生态特征施加了调控影响，显著帮助超积累植物获取营养物质和重金属积累。
