Microorganisms play an integral role in driving phosphorus (P) transformation in forest soils; however, studies on soil P cycling and the molecular mechanisms of microbes activated in response to elevated nitrogen (N) deposition are limited. In this study, we conducted a multilevel field N enrichment experiment in a subtropical P-deficient Moso bamboo () system to evaluate the microbial ecological traits of P transformation (e.g., organic P mineralization and inorganic P solubilization) over three consecutive years. N addition significantly decreased available and organic P levels in the soil and increased the microbial biomass C:P and N:P ratios, indicative of severe microbial P limitation. Consequently, N addition increased the absolute abundance of P starvation response regulation genes ( and ), which further induced an increase in organic P mineralization (, ), but not that of inorganic P solubilization genes ( and ). This suggests that microbes enhance P availability by organic P mineralization rather than inorganic P solubilization to ameliorate reduced P availability. Furthermore, a bacterial functional module (B_Mod#0) consisting of , and accounted for more than 60% of the changes in the abundance of genes responsible for organic P-mineralization in the soil, suggesting that B_Mod#0 acts as a keystone phylotype in enhancing functional P-cycling potential. This study provides novel insights into microorganism-driven P cycling in P-deficient forest soils with N addition.

中文翻译：

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关键细菌功能模块激活磷矿化基因，以增强添加 5 年氮的亚热带森林土壤中有机磷的酶解作用

微生物在驱动森林土壤中磷 (P) 转化方面发挥着不可或缺的作用；然而，关于土壤磷循环和响应氮（N）沉降升高而激活的微生物分子机制的研究有限。在本研究中，我们在亚热带缺磷毛竹系统中进行了多级田间氮富集实验，以评估连续三年磷转化（例如有机磷矿化和无机磷溶解）的微生物生态特征。添加氮显着降低了土壤中有效磷和有机磷的水平，并增加了微生物生物量的 C:P 和 N:P 比率，表明微生物磷的严重限制。因此，氮的添加增加了磷饥饿反应调节基因（和）的绝对丰度，这进一步诱导了有机磷矿化的增加（，），但不增加无机磷溶解基因（和）的增加。这表明微生物通过有机磷矿化而不是无机磷溶解来提高磷的有效性，以改善磷有效性的降低。此外，由 和 组成的细菌功能模块 (B_Mod#0) 解释了负责土壤中有机磷矿化的基因丰度变化的 60% 以上，这表明 B_Mod#0 是土壤中有机磷矿化的关键系统型。增强功能性P-循环潜力。这项研究为缺磷森林土壤中添加氮的微生物驱动的磷循环提供了新的见解。