Work

Enhanced nitrogen load improved soil phosphorus availability by regulating Pcycling microbial genes in a typical subtropical estuary (Min River), Southeast China

Year: 2025

Type: article

Abstract: Enhanced nitrogen (N) load was considered a critical factor influencing phosphorus (P) availability and P-cycling in marsh soils. However, information on the links between soil P availability and microbial genes involved in P-cycling processes under N enrichment conditions remains scarce. A field N load experiment with four treatments (N 0 , N low , N medium , and N high ) was conducted in Cyperus malaccensis marsh of the Min River estuary, and soil P availability, the relative abundances of P-cycling functional genes and their regulatory roles on P availability were investigated. The total phosphorus (TP) contents in soils were significantly positively correlated with N load levels ( p < 0.05). Compared with the N 0 treatment, the TP in the N low , N medium and N high treatments increased by 8.97%, 17.34% and 15.21%, respectively. With increasing N load levels, the proportions of easily- and moderately-available P in TP contents noticeably increased, suggesting that N additions enhanced soil P availability. Metagenomic sequence analyses showed that N enrichment markedly altered the relative abundances of P-cycling functional genes. Briefly, the abundances of inorganic P solubilization genes (particularly ppa and ppx ) increased substantially with increasing N load levels. The total abundances of organic P mineralization genes in the N low and N medium treatments decreased markedly, while those in the N high treatment increased greatly. The abundances of genes coding for phytase ( phy and appA ) markedly increased with increasing N load levels, implying that phytase was more sensitive to N enrichment. Furthermore, enhanced N load noticeably reduced the abundances of genes participated in P transportation (particularly ugpABEC ) and those involved in P-assimilating process (e.g., phoR, phoB , pstABCS and pit ). As affected by enhanced N load, the contents of easily-available P showed strong correlations with the abundances of genes involved in inorganic P solubilization while those of moderately-available P (particularly Sonic-P i , Sonic-P o and NaOH-P i ) were positively correlated with the abundances of genes involved in P regulation and transportation, indicating strong linkages between P-cycling functional genes and soil P availability. This paper found that, under N enrichment conditions, the increased inorganic P solubilization potential and the weakened microbial P immobilization capacity were beneficial to increasing soil P availability.

Source: Environmental Microbiome

DOI: 10.1186/s40793-025-00813-3

Authors: Huihui Wu, Zhigao Sun, Bingbing Chen, Xingyun Hu, Yajin Li

Institutions: Fujian Normal University, Zaozhuang University

Language: English

Topic: Soil Carbon and Nitrogen Dynamics

Subfield: Soil Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,590