Jiajia Li , Zhenhao Wei , Wei Guo , Kang Zhang , Xiaoyu Jia , Zhouping Shangguan
{"title":"模拟根分泌物C:N化学计量对关键微生物类群和微生物呼吸的影响","authors":"Jiajia Li , Zhenhao Wei , Wei Guo , Kang Zhang , Xiaoyu Jia , Zhouping Shangguan","doi":"10.1016/j.apsoil.2025.106196","DOIUrl":null,"url":null,"abstract":"<div><div>Plant roots release carbon (C) and nitrogen (N) compounds into the rhizosphere, thereby enhancing nutrient availability and promoting plant growth. However, the influence of root exudate stoichiometry on soil C cycling is not well understood. This study added root exudate mimics to soil collected from a <em>Robinia pseudoacacia</em> plantation (35 years old). The experiment lasted 110 days and root exudate mimics included water (control), C alone, N alone, and combinations of C and N (C:N ratios of 10, 50 and 100). The cumulative CO<sub>2</sub> flux significantly differed among C:N10, C:N50, C:N100 and CK groups (<em>P</em> < 0.05) and cumulative CO<sub>2</sub> flux significantly increased with increasing exudate C:N ratio (<em>P</em> < 0.05). Meanwhile, bacterial Shannon index decreased with increasing exudate C:N, and increased with increasing incubation time. Permutational Multivariate Analysis of Variance (PERMANOVA) of pairwise distances between bacterial communities indicated that significant differences in bacterial composition over time and in response to exudate inputs. Furthermore, network analysis showed that network complexity increased with increasing root exudate C:N ratio. In module hubs of the bacterial network, the relative abundance of <em>Acidobacteriota</em> and <em>Proteobacteria</em> decreased with increasing exudate C:N ratio, but <em>Actinobacteriota</em> showed an opposite trend. <em>Actinobacteriota</em> and <em>Acidobacteriota</em> were regarded as k-strategists, and <em>Proteobacteria</em> as r-strategists. These results suggested different responses to exudate input by key bacterial taxa with the same life strategy. Finally, partial least squares path analysis showed that root exudate stoichiometry regulated soil respiration via key bacterial taxa and enzyme activity. Our study provides fundamental information on the effects of root exudates on microbial communites, microbial metabolism, and soil C pool stability.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"212 ","pages":"Article 106196"},"PeriodicalIF":4.8000,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effects of simulated root exudate C:N stoichiometry on key microbial taxa and microbial respiration\",\"authors\":\"Jiajia Li , Zhenhao Wei , Wei Guo , Kang Zhang , Xiaoyu Jia , Zhouping Shangguan\",\"doi\":\"10.1016/j.apsoil.2025.106196\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Plant roots release carbon (C) and nitrogen (N) compounds into the rhizosphere, thereby enhancing nutrient availability and promoting plant growth. However, the influence of root exudate stoichiometry on soil C cycling is not well understood. This study added root exudate mimics to soil collected from a <em>Robinia pseudoacacia</em> plantation (35 years old). The experiment lasted 110 days and root exudate mimics included water (control), C alone, N alone, and combinations of C and N (C:N ratios of 10, 50 and 100). The cumulative CO<sub>2</sub> flux significantly differed among C:N10, C:N50, C:N100 and CK groups (<em>P</em> < 0.05) and cumulative CO<sub>2</sub> flux significantly increased with increasing exudate C:N ratio (<em>P</em> < 0.05). Meanwhile, bacterial Shannon index decreased with increasing exudate C:N, and increased with increasing incubation time. Permutational Multivariate Analysis of Variance (PERMANOVA) of pairwise distances between bacterial communities indicated that significant differences in bacterial composition over time and in response to exudate inputs. Furthermore, network analysis showed that network complexity increased with increasing root exudate C:N ratio. In module hubs of the bacterial network, the relative abundance of <em>Acidobacteriota</em> and <em>Proteobacteria</em> decreased with increasing exudate C:N ratio, but <em>Actinobacteriota</em> showed an opposite trend. <em>Actinobacteriota</em> and <em>Acidobacteriota</em> were regarded as k-strategists, and <em>Proteobacteria</em> as r-strategists. These results suggested different responses to exudate input by key bacterial taxa with the same life strategy. Finally, partial least squares path analysis showed that root exudate stoichiometry regulated soil respiration via key bacterial taxa and enzyme activity. Our study provides fundamental information on the effects of root exudates on microbial communites, microbial metabolism, and soil C pool stability.</div></div>\",\"PeriodicalId\":8099,\"journal\":{\"name\":\"Applied Soil Ecology\",\"volume\":\"212 \",\"pages\":\"Article 106196\"},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2025-05-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Soil Ecology\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0929139325003348\",\"RegionNum\":2,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"SOIL SCIENCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Soil Ecology","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0929139325003348","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"SOIL SCIENCE","Score":null,"Total":0}
引用次数: 0
摘要
植物根系向根际释放碳(C)和氮(N)化合物,从而提高养分有效性,促进植物生长。然而,根系分泌物化学计量对土壤碳循环的影响尚不清楚。本研究在35年的刺槐人工林土壤中添加了根系分泌物模拟物。试验期110 d,根系分泌物模拟物包括水(对照)、单独碳、单独氮和碳氮组合(碳氮比分别为10、50和100)。累积CO2通量在C:N10、C:N50、C:N100和CK组间差异显著(P <;0.05),累积CO2通量随渗出物碳氮比的增加而显著增加(P <;0.05)。细菌香农指数随渗出液C:N的增加而降低,随培养时间的延长而升高。排列多元方差分析(Permutational Multivariate Analysis of Variance, PERMANOVA)对细菌群落之间的两两距离进行了分析,结果表明细菌组成随着时间的推移和对渗出物输入的反应存在显著差异。此外,网络分析表明,随着根系分泌物C:N比的增加,网络复杂性增加。在细菌网络的模块中心,酸性菌群和变形菌群的相对丰度随着渗出液C:N比值的增加而降低,而放线菌群的相对丰度则相反。放线菌门和酸杆菌门被认为是k型战略菌,变形菌门被认为是r型战略菌。这些结果表明,具有相同生命策略的关键细菌类群对渗出物输入的响应不同。最后,偏最小二乘通径分析表明,根系分泌物化学计量学通过关键细菌类群和酶活性调节土壤呼吸。我们的研究为根系分泌物对微生物群落、微生物代谢和土壤碳库稳定性的影响提供了基础信息。
Effects of simulated root exudate C:N stoichiometry on key microbial taxa and microbial respiration
Plant roots release carbon (C) and nitrogen (N) compounds into the rhizosphere, thereby enhancing nutrient availability and promoting plant growth. However, the influence of root exudate stoichiometry on soil C cycling is not well understood. This study added root exudate mimics to soil collected from a Robinia pseudoacacia plantation (35 years old). The experiment lasted 110 days and root exudate mimics included water (control), C alone, N alone, and combinations of C and N (C:N ratios of 10, 50 and 100). The cumulative CO2 flux significantly differed among C:N10, C:N50, C:N100 and CK groups (P < 0.05) and cumulative CO2 flux significantly increased with increasing exudate C:N ratio (P < 0.05). Meanwhile, bacterial Shannon index decreased with increasing exudate C:N, and increased with increasing incubation time. Permutational Multivariate Analysis of Variance (PERMANOVA) of pairwise distances between bacterial communities indicated that significant differences in bacterial composition over time and in response to exudate inputs. Furthermore, network analysis showed that network complexity increased with increasing root exudate C:N ratio. In module hubs of the bacterial network, the relative abundance of Acidobacteriota and Proteobacteria decreased with increasing exudate C:N ratio, but Actinobacteriota showed an opposite trend. Actinobacteriota and Acidobacteriota were regarded as k-strategists, and Proteobacteria as r-strategists. These results suggested different responses to exudate input by key bacterial taxa with the same life strategy. Finally, partial least squares path analysis showed that root exudate stoichiometry regulated soil respiration via key bacterial taxa and enzyme activity. Our study provides fundamental information on the effects of root exudates on microbial communites, microbial metabolism, and soil C pool stability.
期刊介绍:
Applied Soil Ecology addresses the role of soil organisms and their interactions in relation to: sustainability and productivity, nutrient cycling and other soil processes, the maintenance of soil functions, the impact of human activities on soil ecosystems and bio(techno)logical control of soil-inhabiting pests, diseases and weeds.