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Procyanidin inhibited N2O emissions from paddy soils by affecting nitrate reductase activity and nirS- and nirK-denitrifier populations

Biology and Fertility of Soils volume 57, pages 935–947 (2021)Cite this article

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Abstract

A 28-day microcosm experiment was conducted using three paddy soils (an alluvial paddy soil, a loess-formed paddy soil, and a yellow clayey paddy soil) to investigate the impact of procyanidin on N2O emissions and associated microbial mechanisms. The efficacy of procyanidin on N2O emissions varied among the paddy soils tested, with an average inhibition rate ranging from 2.7% in the alluvial paddy soil to 57.1% in the loess-formed paddy soil. Furthermore, suppression of N2O emissions by procyanidin occurred alongside fluctuations in nitrate reductase activity and nirS- and nirK-type denitrifiers abundance. The correlation analysis indicates that nitrate reductase, clade I nirS-denitrifiers, clade I or II, and clade III nirK-denitrifiers were closely linked to N2O emissions. These findings provide evidence that procyanidin is capable of limiting N2O emissions in paddy soils by inhibiting nitrate reductase and different clades of nirS-/nirK-denitrifiers.

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References

  • Abdelmagid HM, Tabatabai MA (1987) Nitrate reductase activity of soils. Soil Biol Biochem 19:421–427

    CAS  Article  Google Scholar 

  • Akiyama H, Yan X, Yagi K (2010) Evaluation of effectiveness of enhanced-efficiency fertilizers as mitigation options for N2O and NO emissions from agricultural soils: meta-analysis. Glob Chang Biol 16:1837–1846

    Article  Google Scholar 

  • Bardon C, Piola F, Bellvert F, Haichar FZ, Comte G, Meiffren G, Pommier T, Puijalon S, Tsafack N, Poly F (2014) Evidence for biological denitrification inhibition (BDI) by plant secondary metabolites. New Phytol 204:620–630

    CAS  PubMed  Article  Google Scholar 

  • Bardon C, Piola F, Haichar FZ, Meiffren G, Comte G, Missery B, Balby M, Poly F (2016a) Identification of B-type procyanidins in Fallopia spp. involved in biological denitrification inhibition. Environ Microbiol 18:644–655

  • Bardon C, Poly F, Piola F, Pancton M, Comte G, Meiffren G, Haichar FZ (2016b) Mechanism of biological denitrification inhibition: procyanidins induce an allosteric transition of the membrane-bound nitrate reductase through membrane alteration. FEMS Microbiol Ecol 92:fiw034

  • Bardon C, Poly F, Haichar FZ, Le Roux X, Simon L, Meiffren G, Comte G, Rouifed S, Piola F (2017) Biological denitrification inhibition (BDI) with procyanidins induces modification of root traits, growth and N status in Fallopia x bohemica. Soil Biol Biochem 107:41–49

    CAS  Article  Google Scholar 

  • Bateman EJ, Baggs EM (2005) Contributions of nitrification and denitrification to N2O emissions from soils at different water-filled pore space. Biol Fertil Soils 41:379–388

    CAS  Article  Google Scholar 

  • Bhat TK, Singh B, Sharma OP (1998) Microbial degradation of tannins – a current perspective. Biodegradation 9:343–357

    CAS  PubMed  Article  Google Scholar 

  • Bhatia A, Sasmal S, Jain N, Pathak H, Kumar R, Singh A (2010) Mitigating nitrous oxide emission from soil under conventional and no-tillage in wheat using nitrification inhibitors. Agr Ecosyst Environ 136:247–253

    CAS  Article  Google Scholar 

  • Bremner JM, Mulvaney CS (1982) Nitrogen-total. In: Page AL, Miller RH, Keeney DR (eds) Methods of soil analysis, part 2. Chemical and microbiological properties. American Society of Agronomy, Madison, pp 595–624

  • Butterbach-Bahl K, Baggs EM, Dannenmann M, Kiese R, Zechmeister-Boltenstern S (2013) Nitrous oxide emissions from soils: how well do we understand the processes and their controls? Philos Trans R Soc Lond B Biol Sci 368:20130122

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  • Chen H, Yin C, Fan X, Ye M, Peng H, Li T, Zhao Y, Wakelin SA, Chu G, Liang Y (2019) Reduction of N2O emission by biochar and/or 3,4-dimethylpyrazole phosphate (DMPP) is closely linked to soil ammonia oxidizing bacteria and nosZI-N2O reducer populations. Sci Total Environ 694:133658

    CAS  PubMed  Article  Google Scholar 

  • Chen S, Wang F, Zhang Y, Qin S, Wei S, Wang S, Hu C, Liu B (2018) Organic carbon availability limiting microbial denitrification in the deep vadose zone. Environ Microbiol 20:980–992

    CAS  PubMed  Article  Google Scholar 

  • Cheng Y, Wang J, Wang J, Chang SX, Wang S (2017) The quality and quantity of exogenous organic carbon input control microbial NO3¯ immobilization: a meta-analysis. Soil Biol Biochem 115:357–363

    CAS  Article  Google Scholar 

  • Cui P, Fan F, Yin C, Song A, Huang P, Tang Y, Zhu P, Peng C, Li T, Wakelin SA, Liang Y (2016) Long-term organic and inorganic fertilization alters temperature sensitivity of potential N2O emissions and associated microbes. Soil Biol Biochem 93:131–141

    CAS  Article  Google Scholar 

  • Dassonville N, Guillaumaud N, Piola F, Meerts P, Poly F (2011) Niche construction by the invasive Asian knotweeds (species complex Fallopia): impact on activity, abundance and community structure of denitrifiers and nitrifiers. Biol Invasions 13:1115–1133

    Article  Google Scholar 

  • Denmead OT, Freney JR, Simpson JR (1976) Closed ammonia cycle within a plant canopy. Soil Biol Biochem 8:161–164

    CAS  Article  Google Scholar 

  • Dixon RA, Xie DY, Sharma SB (2005) Proanthocyanidins-a final frontier in flavonoid research? New Phytol 165:9–28

    CAS  PubMed  Article  Google Scholar 

  • Enwall K, Philippot L, Hallin S (2005) Activity and composition of the denitrifying bacterial community respond differently to long-term fertilization. Appl Environ Microbiol 71:8335–8343

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  • Fan X, Yin C, Chen H, Ye M, Zhao Y, Li T, Wakelin SA, Liang Y (2019) The efficacy of 3,4-dimethylpyrazole phosphate on N2O emissions is linked to niche differentiation of ammonia oxidizing archaea and bacteria across four arable soils. Soil Biol Biochem 130:82–93

    CAS  Article  Google Scholar 

  • Forte A, Fierro A (2019) Denitrification rate and its potential to predict biogenic N2O field emissions in a Mediterranean maize-cropped soil in southern Italy. Land 8:97

    Article  Google Scholar 

  • Galland W, Piola F, Burlet A, Mathieu C, Nardy M, Poussineau S, Blazère L, Gervaix J, Puijalon S, Simon L, Haichar FZ (2019) Biological denitrification inhibition (BDI) in the field: a strategy to improve plant nutrition and growth. Soil Biol Biochem 136:107513

  • Galland W, Haichar FZ, Czarnes S, Mathieu C, Demorge J-L, Simon L, Puijalon S, Piola F (2021) Biological inhibition of denitrification (BDI) in the field: effect on plant growth in two different soils. Appl Soil Ecol 159:103857

  • Hu HW, Chen D, He JZ (2015) Microbial regulation of terrestrial nitrous oxide formation: understanding the biological pathways for prediction of emission rates. FEMS Microbiol Rev 39:729–749

    CAS  PubMed  Article  Google Scholar 

  • Huang T, Gao B, Hu XK, Lu X, Well R, Christie P, Bakken LR, Ju XT (2014) Ammonia-oxidation as an engine to generate nitrous oxide in an intensively managed calcareous fluvo-aquic soil. Sci Rep 4:3950

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  • IPCC (2014) Climate change 2014: mitigation of climate change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK. and New York, NY, USA

  • Jones CM, Stres B, Rosenquist M, Hallin S (2008) Phylogenetic analysis of nitrite, nitric oxide, and nitrous oxide respiratory enzymes reveal a complex evolutionary history for denitrification. Mol Biol Evol 25:1955–1966

    CAS  PubMed  Article  Google Scholar 

  • Kalembasa SJ, Jenkinson DS (1973) A comparative study of titrimetric and gravimetric methods for the determination of organic carbon in soil. J Sci Food Agric 24:1085–1090

    CAS  Article  Google Scholar 

  • Kandeler E, Deiglmayr K, Tscherko D, Bru D, Philippot L (2006) Abundance of narG, nirS, nirK, and nosZ genes of denitrifying bacteria during primary successions of a glacier foreland. Appl Environ Microbiol 72:5957–5962

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  • Köster JR, Cárdenas LM, Bol R, Lewicka-Szczebak D, Senbayram M, Well R, Giesemann A, Dittert K (2015) Anaerobic digestates lower N2O emissions compared to cattle slurry by affecting rate and product stoichiometry of denitrification – an N2O isotopomer case study. Soil Biol Biochem 84:65–74

    Article  CAS  Google Scholar 

  • Kraal P, Nierop KGJ, Kaal J, Tietema A (2009) Carbon respiration and nitrogen dynamics in Corsican pine litter amended with aluminium and tannins. Soil Biol Biochem 41:2318–2327

    CAS  Article  Google Scholar 

  • Kraus TEC, Zasoski RJ, Dahlgren RA, Horwath WR, Preston CM (2004) Carbon and nitrogen dynamics in a forest soil amended with purified tannins from different plant species. Soil Biol Biochem 36:309–321

    CAS  Article  Google Scholar 

  • Kuypers MMM, Marchant HK, Kartal B (2018) The microbial nitrogen-cycling network. Nat Rev Microbiol 16:263–276

    CAS  PubMed  Article  Google Scholar 

  • Lan T, Han Y, Cai Z (2015) Denitrification and its product composition in typical Chinese paddy soils. Biol Fertil Soils 51:89–98

    CAS  Article  Google Scholar 

  • Li J, Kwak JH, Chen J, An Z, Gong X, Chang SX (2021a) Canola straw biochars produced under different pyrolysis temperatures and nitrapyrin independently affected cropland soil nitrous oxide emissions. Biol Fertil Soils 57:319–328

    CAS  Article  Google Scholar 

  • Li Z, Zeng Z, Song Z, Wang F, Tian D, Mi W, Huang X, Wang J, Song L, Yang Z, Wang J, Feng H, Jiang L, Chen Y, Luo Y, Niu S (2021b) Vital roles of soil microbes in driving terrestrial nitrogen immobilization. Glob Chang Biol 27:1848–1858

    PubMed  Article  Google Scholar 

  • Linquist BA, Anders MM, Adviento-Borbe MA, Chaney RL, Nalley LL, da Rosa EF, van Kessel C (2015) Reducing greenhouse gas emissions, water use, and grain arsenic levels in rice systems. Glob Chang Biol 21:407–417

    PubMed  Article  Google Scholar 

  • Longo E, Rossetti F, Merkyte V, Obiedzińska A, Boselli E (2018) Selective binding of potassium and calcium ions to novel cyclic proanthocyanidins in wine by high-performance liquid chromatography/high-resolution mass spectrometry. Rapid Commun Mass Spectrom 32:1637–1642

    CAS  Article  Google Scholar 

  • Malique F, Ke P, Boettcher J, Dannenmann M, Butterbach-Bahl K (2019) Plant and soil effects on denitrification potential in agricultural soils. Plant Soil 439:459–474

    CAS  Article  Google Scholar 

  • Martiny JB, Bohannan BJ, Brown JH, Colwell RK, Fuhrman JA, Green JL, Horner-Devine MC, Kane M, Krumins JA, Kuske CR, Morin PJ, Naeem S, Øvreås L, Reysenbach AL, Smith VH, Staley JT (2006) Microbial biogeography: putting microorganisms on the map. Nat Rev Microbiol 4:102–112

    CAS  PubMed  Article  Google Scholar 

  • Mathieu O, Henault C, Leveque J, Baujard E, Milloux MJ, Andreux F (2006) Quantifying the contribution of nitrification and denitrification to the nitrous oxide flux using 15N tracers. Environ Pollut 144:933–940

    CAS  PubMed  Article  Google Scholar 

  • Meng X, Li Y, Yao H, Wang J, Dai F, Wu Y, Chapman S (2020) Nitrification and urease inhibitors improve rice nitrogen uptake and prevent denitrification in alkaline paddy soil. Appl Soil Ecol 154:103665

    Article  Google Scholar 

  • Montzka SA, Dlugokencky EJ, Butler JH (2011) Non-CO2 greenhouse gases and climate change. Nature 476:43–50

    CAS  PubMed  Article  Google Scholar 

  • Morse JL, Ardón M, Bernhardt ES (2012) Using environmental variables and soil processes to forecast denitrification potential and nitrous oxide fluxes in coastal plain wetlands across different land uses. J Geophys Res-Biogeo 117:G02023

    Article  CAS  Google Scholar 

  • Murphy J, Riley JP (1962) A modified single solution method for the determination of phosphate in natural waters. Anal Chim Acta 27:31–36

    CAS  Article  Google Scholar 

  • Nelson MB, Martiny AC, Martiny JB (2016) Global biogeography of microbial nitrogen-cycling traits in soil. Proc Natl Acad Sci U S A 113:8033–8040

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  • Norman RJ, Edberg JC, Stucki JW (1985) Determination of nitrate in soil extracts by dual-wavelength ultraviolet spectrophotometry. Soil Sci Soc Am J 49:1182–1185

    CAS  Article  Google Scholar 

  • Olsen SR, Cole CV, Watanabe FS, Dean LA (1954) Estimation of available phosphorus in soils by extraction with sodium bicarbonate. USDA Circular 939:1–19

    Google Scholar 

  • Pandey A, Suter H, He JZ, Hu HW, Chen D (2021) Dissimilatory nitrate ammonification and N2 fixation helps maintain nitrogen nutrition in resource-limited rice paddies. Biol Fertil Soils 57:107–115

    CAS  Article  Google Scholar 

  • Pu Y, Zhu B, Dong Z, Liu Y, Wang C, Ye C (2019) Soil N2O and NOx emissions are directly linked with N-cycling enzymatic activities. Appl Soil Ecol 139:15–24

    Article  Google Scholar 

  • Putz M, Schleusner P, Rütting T, Hallin S (2018) Relative abundance of denitrifying and DNRA bacteria and their activity determine nitrogen retention or loss in agricultural soil. Soil Biol Biochem 123:97–104

    CAS  Article  Google Scholar 

  • Qiao C, Liu L, Hu S, Compton JE, Greaver TL, Li Q (2015) How inhibiting nitrification affects nitrogen cycle and reduces environmental impacts of anthropogenic nitrogen input. Glob Chang Biol 21:1249–1257

    PubMed  Article  Google Scholar 

  • Qiu Y, Jiang Y, Guo L, Burkey KO, Zobel RW, Shew HD, Hu S (2018) Contrasting warming and ozone effects on denitrifiers dominate soil N2O emissions. Environ Sci Technol 52:10956–10966

    CAS  PubMed  Article  Google Scholar 

  • R Core Team (2021) A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. Available online at https://www.R-project.org/

  • Ravishankara AR, Daniel JS, Portmann RW (2009) Nitrous oxide (N2O): the dominant ozone-depleting substance emitted in the 21st century. Science 326:123–125

    CAS  PubMed  Article  Google Scholar 

  • Rodrigues JM, Lasa B, Aparicio-Tejo PM, Gonzalez-Murua C, Marino D (2018) 3,4-Dimethylpyrazole phosphate and 2-(N-3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture nitrification inhibitors: quantification in plant tissues and toxicity assays. Sci Total Environ 624:1180–1186

    CAS  PubMed  Article  Google Scholar 

  • Saito T, Ishii S, Otsuka S, Nishiyama M, Senoo K (2008) Identification of novel betaproteobacteria in a succinate-assimilating population in denitrifying rice paddy soil by using stable isotope probing. Microbes Environ 23:192–200

    PubMed  Article  Google Scholar 

  • Shaukat M, Samoy-Pascual K, Maas E, Ahmad A (2019) Simultaneous effects of biochar and nitrogen fertilization on nitrous oxide and methane emissions from paddy rice. J Environ Manage 248:109242

    CAS  PubMed  Article  Google Scholar 

  • Silver WL, Herman DJ, Firestone MK (2001) Dissimilatory nitrate reduction to ammonium in upland tropical forest soils. Ecology 82:2410–2416

    Article  Google Scholar 

  • Šimek M, Elhottová D, Klimeš F, Hopkins DW (2004) Emissions of N2O and CO2, denitrification measurements and soil properties in red clover and ryegrass stands. Soil Biol Biochem 36:9–21

    Article  CAS  Google Scholar 

  • Song A, Fan F, Yin C, Wen S, Zhang Y, Fan X, Liang Y (2017) The effects of silicon fertilizer on denitrification potential and associated genes abundance in paddy soil. Biol Fertil Soils 53:627–638

    CAS  Article  Google Scholar 

  • Standford S, English L (1949) Use of flame photometer in rapid soil test for K and Ca. Agron J 41:446–447

    Article  Google Scholar 

  • Tao R, Wakelin SA, Liang Y, Hu B, Chu G (2018) Nitrous oxide emission and denitrifier communities in drip-irrigated calcareous soil as affected by chemical and organic fertilizers. Sci Total Environ 612:739–749

    CAS  PubMed  Article  Google Scholar 

  • Thomas RL, Sheard RW, Moyer JR (1967) Comparison of conventional and automated procedures for nitrogen, phosphorus, and potassium analysis of plant material using a single digestion. Agron J 59:240–243

    CAS  Article  Google Scholar 

  • Volpi I, Laville P, Bonari E, di Nasso NNo, Bosco S, (2017) Improving the management of mineral fertilizers for nitrous oxide mitigation: the effect of nitrogen fertilizer type, urease and nitrification inhibitors in two different textured soils. Geoderma 307:181–188

    CAS  Article  Google Scholar 

  • Wang S, Shan J, Xia Y, Tang Q, Xia L, Lin J, Yan X (2017) Different effects of biochar and a nitrification inhibitor application on paddy soil denitrification: a field experiment over two consecutive rice-growing seasons. Sci Total Environ 593–594:347–356

    PubMed  Google Scholar 

  • Wei W, Isobe K, Nishizawa T, Zhu L, Shiratori Y, Ohte N, Koba K, Otsuka S, Senoo K (2015) Higher diversity and abundance of denitrifying microorganisms in environments than considered previously. ISME J 9:1954–1965

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  • Wu D, Senbayram M, Well R, Brüggemann N, Pfeiffer B, Loick N, Stempfhuber B, Dittert K, Bol R (2017) Nitrification inhibitors mitigate N2O emissions more effectively under straw-induced conditions favoring denitrification. Soil Biol Biochem 104:197–207

    CAS  Article  Google Scholar 

  • Xia L, Li X, Ma Q, Lam SK, Wolf B, Kiese R, Butterbach-Bahl K, Chen D, Li Z, Yan X (2020) Simultaneous quantification of N2, NH3 and N2O emissions from a flooded paddy field under different N fertilization regimes. Glob Chang Biol 26:2292–2303

    Article  Google Scholar 

  • Yin C, Fan F, Song A, Cui P, Li T, Liang Y (2015) Denitrification potential under different fertilization regimes is closely coupled with changes in the denitrifying community in a black soil. Appl Microbiol Biot 99:5719–5729

    CAS  Article  Google Scholar 

  • Yin C, Fan F, Song A, Fan X, Ding H, Ran W, Qiu H, Liang Y (2017) The response patterns of community traits of N2O emission-related functional guilds to temperature across different arable soils under inorganic fertilization. Soil Biol Biochem 108:65–77

    CAS  Article  Google Scholar 

  • Yoon S, Cruz-García C, Sanford R, Ritalahti KM, Löffler FE (2015) Denitrification versus respiratory ammonification: environmental controls of two competing dissimilatory NO3¯/NO2¯ reduction pathways in Shewanella loihica strain PV-4. ISME J 9:1093–1104

  • Yoshida M, Ishii S, Otsuka S, Senoo K (2009) Temporal shifts in diversity and quantity of nirS and nirK in a rice paddy field soil. Soil Biol Biochem 41:2044–2051

    CAS  Article  Google Scholar 

  • Zhang J, Lan T, Müller C, Cai Z (2015a) Dissimilatory nitrate reduction to ammonium (DNRA) plays an important role in soil nitrogen conservation in neutral and alkaline but not acidic rice soil. J Soil Sediment 15:523–531

    Article  CAS  Google Scholar 

  • Zhang J, Müller C, Cai Z (2015b) Heterotrophic nitrification of organic N and its contribution to nitrous oxide emissions in soils. Soil Biol Biochem 84:199–209

    CAS  Article  Google Scholar 

  • Zumft WG (1997) Cell biology and molecular basis of denitrification. Microbiol Mol Biol R 61:533–616

    CAS  Google Scholar 

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Acknowledgements

We thank the Soil and Fertilizer Technical Guidance Station of Jintan City for managing the field experiment and for the assistance in the field. We are also grateful to two anonymous reviewers and the Editor-in-Chief for their instructive comments and suggestions that improved an earlier version of this manuscript.

Funding

This work was jointly supported by grants from Zhejiang Provincial Science and Technology Programs (2018C02036), National Key Research and Development Programs of China (2017YFD0200707), and the Fundamental Research Funds for the Central Universities (2019FZJD007).

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  1. Ministry of Education Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China

    Mujun Ye, Chang Yin, Xiaoping Fan, Zixiang Gao, Hao Chen, Li Tan & Yongchao Liang

  2. Department of Renewable Resources, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada

    Scott X. Chang

  3. College of Life Sciences, Zhejiang University, Hangzhou, 310058, China

    Yuhua Zhao

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  1. Mujun Ye
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  2. Chang Yin
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Ye, M., Yin, C., Fan, X. et al. Procyanidin inhibited N2O emissions from paddy soils by affecting nitrate reductase activity and nirS- and nirK-denitrifier populations. Biol Fertil Soils 57, 935–947 (2021). https://doi.org/10.1007/s00374-021-01576-y

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Keywords

  • Nitrous oxide
  • Procyanidin
  • Nitrate reductase activity
  • Denitrifiers