Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter Decomposition
Arbuscular mycorrhizal fungi (AMF) can preferentially absorb the released ammonium (NH<sub>4</sub><sup>+</sup>) over nitrate (NO<sub>3</sub><sup>−</sup>) during litter decomposition. However, the impact of AMF’s absorption of NH<sub>4</sub>...
Saved in:
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
|
| Series: | Microorganisms |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-2607/13/1/151 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832587882710171648 |
|---|---|
| author | Yuehong Gao Xiaoyu Long Yiqi Liao Yonghui Lin Zaihua He Qin Kong Xiangshi Kong Xingbing He |
| author_facet | Yuehong Gao Xiaoyu Long Yiqi Liao Yonghui Lin Zaihua He Qin Kong Xiangshi Kong Xingbing He |
| author_sort | Yuehong Gao |
| collection | DOAJ |
| description | Arbuscular mycorrhizal fungi (AMF) can preferentially absorb the released ammonium (NH<sub>4</sub><sup>+</sup>) over nitrate (NO<sub>3</sub><sup>−</sup>) during litter decomposition. However, the impact of AMF’s absorption of NH<sub>4</sub><sup>+</sup> on litter nitrogen (N) decomposition is still unclear. In this study, we investigated the effects of AMF uptake for NH<sub>4</sub><sup>+</sup> on litter N metabolic characteristics by enriching NH<sub>4</sub><sup>+</sup> via AMF suppression and nitrification inhibition in a subtropical <i>Cinnamomum camphora</i> forest. The results showed that AMF suppression and nitrification inhibition significantly decelerated litter decomposition in the early stage due to the repression of NH<sub>4</sub><sup>+</sup> in extracellular enzyme activity. In the late stage, when soil NH<sub>4</sub><sup>+</sup> content was low, in contrast, they promoted litter decomposition by increasing the extracellular enzyme activities. Nitrification inhibition mainly promoted the utilization of plant-derived N by promoting the degradation of the amide I, amide II, and III bands by increasing protease activity, and it promoted ammonification by increasing urease activities, whereas it reduced the utilization of microbial-derived N by decreasing chitinase activity. On the contrary, AMF suppression, which significantly reduced the ammonification rate and increased the nitrification rate, only facilitated the degradation of the amide II band. Moreover, it intensified the microbial-derived N decomposition by increasing chitinase activity. The degradation of the amide I and II bands still relied on the priming effects of AMF on soil saprotrophs. This was likely driven by AMF-mediated phosphorus (P) mineralization. Nutrient acquiring, especially P by phosphatase, were the main factors in predicting litter decomposition and protein degradation. Thus, AMF could relieve the end-product repression of locally enriched NH<sub>4</sub><sup>+</sup> in extracellular enzyme activity and promote early-stage litter decomposition. However, the promotive effects of AMF on litter protein degradation and NH<sub>4</sub><sup>+</sup> release rely on P mineralization. Our results demonstrated that AMF could alleviate the N limitation for net primary production via accelerating litter N decomposition and reducing N loss. Moreover, they could restrict the decomposition of recalcitrant components by competing with saprotrophs for nutrients. Both pathways will contribute to C sequestration in forest ecosystems, which advances our understanding of AMF’s contribution to nutrient cycling and ecosystem processes in subtropical forests. |
| format | Article |
| id | doaj-art-c7ba72bd950f499bb2209a7871c82471 |
| institution | Kabale University |
| issn | 2076-2607 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj-art-c7ba72bd950f499bb2209a7871c824712025-01-24T13:42:50ZengMDPI AGMicroorganisms2076-26072025-01-0113115110.3390/microorganisms13010151Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter DecompositionYuehong Gao0Xiaoyu Long1Yiqi Liao2Yonghui Lin3Zaihua He4Qin Kong5Xiangshi Kong6Xingbing He7College of Biology and Environmental Sciences, Jishou University, Jishou 416000, ChinaCollege of Biology and Environmental Sciences, Jishou University, Jishou 416000, ChinaKey Laboratory for Ecotourism of Hunan Province, School of Tourism, Jishou University, Jishou 416000, ChinaCollege of Biology and Environmental Sciences, Jishou University, Jishou 416000, ChinaCollege of Biology and Environmental Sciences, Jishou University, Jishou 416000, ChinaCollege of Biology and Environmental Sciences, Jishou University, Jishou 416000, ChinaCollege of Biology and Environmental Sciences, Jishou University, Jishou 416000, ChinaCollege of Biology and Environmental Sciences, Jishou University, Jishou 416000, ChinaArbuscular mycorrhizal fungi (AMF) can preferentially absorb the released ammonium (NH<sub>4</sub><sup>+</sup>) over nitrate (NO<sub>3</sub><sup>−</sup>) during litter decomposition. However, the impact of AMF’s absorption of NH<sub>4</sub><sup>+</sup> on litter nitrogen (N) decomposition is still unclear. In this study, we investigated the effects of AMF uptake for NH<sub>4</sub><sup>+</sup> on litter N metabolic characteristics by enriching NH<sub>4</sub><sup>+</sup> via AMF suppression and nitrification inhibition in a subtropical <i>Cinnamomum camphora</i> forest. The results showed that AMF suppression and nitrification inhibition significantly decelerated litter decomposition in the early stage due to the repression of NH<sub>4</sub><sup>+</sup> in extracellular enzyme activity. In the late stage, when soil NH<sub>4</sub><sup>+</sup> content was low, in contrast, they promoted litter decomposition by increasing the extracellular enzyme activities. Nitrification inhibition mainly promoted the utilization of plant-derived N by promoting the degradation of the amide I, amide II, and III bands by increasing protease activity, and it promoted ammonification by increasing urease activities, whereas it reduced the utilization of microbial-derived N by decreasing chitinase activity. On the contrary, AMF suppression, which significantly reduced the ammonification rate and increased the nitrification rate, only facilitated the degradation of the amide II band. Moreover, it intensified the microbial-derived N decomposition by increasing chitinase activity. The degradation of the amide I and II bands still relied on the priming effects of AMF on soil saprotrophs. This was likely driven by AMF-mediated phosphorus (P) mineralization. Nutrient acquiring, especially P by phosphatase, were the main factors in predicting litter decomposition and protein degradation. Thus, AMF could relieve the end-product repression of locally enriched NH<sub>4</sub><sup>+</sup> in extracellular enzyme activity and promote early-stage litter decomposition. However, the promotive effects of AMF on litter protein degradation and NH<sub>4</sub><sup>+</sup> release rely on P mineralization. Our results demonstrated that AMF could alleviate the N limitation for net primary production via accelerating litter N decomposition and reducing N loss. Moreover, they could restrict the decomposition of recalcitrant components by competing with saprotrophs for nutrients. Both pathways will contribute to C sequestration in forest ecosystems, which advances our understanding of AMF’s contribution to nutrient cycling and ecosystem processes in subtropical forests.https://www.mdpi.com/2076-2607/13/1/151arbuscular mycorrhizal fungiextracellular enzyme activitylitter decompositionnitrogen mineralizationprotein degradation |
| spellingShingle | Yuehong Gao Xiaoyu Long Yiqi Liao Yonghui Lin Zaihua He Qin Kong Xiangshi Kong Xingbing He Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter Decomposition Microorganisms arbuscular mycorrhizal fungi extracellular enzyme activity litter decomposition nitrogen mineralization protein degradation |
| title | Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter Decomposition |
| title_full | Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter Decomposition |
| title_fullStr | Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter Decomposition |
| title_full_unstemmed | Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter Decomposition |
| title_short | Influence of Arbuscular Mycorrhizal Fungi on Nitrogen Dynamics During <i>Cinnamomum camphora</i> Litter Decomposition |
| title_sort | influence of arbuscular mycorrhizal fungi on nitrogen dynamics during i cinnamomum camphora i litter decomposition |
| topic | arbuscular mycorrhizal fungi extracellular enzyme activity litter decomposition nitrogen mineralization protein degradation |
| url | https://www.mdpi.com/2076-2607/13/1/151 |
| work_keys_str_mv | AT yuehonggao influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition AT xiaoyulong influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition AT yiqiliao influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition AT yonghuilin influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition AT zaihuahe influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition AT qinkong influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition AT xiangshikong influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition AT xingbinghe influenceofarbuscularmycorrhizalfungionnitrogendynamicsduringicinnamomumcamphorailitterdecomposition |