Large fraction of mineral nutrients in natural soil environments is recycled from complex and heterogeneously distributed organic sources. These sources are explored by both roots and associated mycorrhizal fungi. However, the mechanisms behind the responses of arbuscular mycorrhizal (AM) hyphal networks to soil organic patches of different qualities remain little understood. Therefore, we conducted a multiple-choice experiment examining hyphal responses to different soil patches within the root-free zone by two AM fungal species (Rhizophagus irregularis and Claroideoglomus claroideum) associated with Medicago truncatula, a legume forming nitrogen-fixing root nodules. Hyphal colonization of the patches was assessed microscopically and by quantitative real-time PCR (qPCR) using AM taxon-specific markers, and the prokaryotic and fungal communities in the patches (pooled per organic amendment treatment) were profiled by 454-amplicon sequencing. Specific qPCR markers were then designed and used to quantify the abundance of prokaryotic taxa showing the strongest correlation with the pattern of AM hyphal proliferation in the organic patches as per the 454-sequencing. The hyphal density of both AM fungi increased due to nitrogen (N)-containing organic amendments (i.e., chitin, DNA, albumin, and clover biomass), while no responses as compared to the non-amended soil patch were recorded for cellulose, phytate, or inorganic phosphate amendments. Abundances of several prokaryotes, including Nitrosospira sp. (an ammonium oxidizer) and an unknown prokaryote with affiliation to Acanthamoeba endosymbiont, which were frequently recorded in the 454-sequencing profiles, correlated positively with the hyphal responses of R. irregularis to the soil amendments. Strong correlation between abundance of these two prokaryotes and the hyphal responses to organic soil amendments by both AM fungi was then confirmed by qPCR analyses using all individual replicate patch samples. Further research is warranted to ascertain the causality of these correlations and particularly which direct roles (if any) do these prokaryotes play in the observed AM hyphal responses to organic N amendment, organic N utilization by the AM fungus and its (N-unlimited) host plant. Further, possible trophic dependencies between the different players in the AM hyphosphere needs to be elucidated upon decomposing the organic N sources.

Laboratory of Fungal Biology Institute of Microbiology Czech Academy of Sciences Prague Czech Republic

Zobrazit více v PubMed

Alberton O., Kuyper T. W., Gorissen A. (2005). Taking mycocentrism seriously: mycorrhizal fungal and plant responses to elevated CO2. New Phytol. 167 859–868. 10.1111/j.1469-8137.2005.01458.x PubMed DOI

Bago B., Cano C., Azcón-Aguilar C., Samson J., Coughlan A. P., Piché Y. (2004). Differential morphogenesis of the extraradical mycelium of an arbuscular mycorrhizal fungus grown monoxenically on spatially heterogeneous culture media. Mycologia 96 452–462. 10.2307/3762165 PubMed DOI

Bago B., Vierheilig H., Piché Y., Azcón-Aguilar C. (1996). Nitrate depletion and pH changes induced by the extraradical mycelium of the arbuscular mycorrhizal fungus Glomus intraradices grown in monoxenic culture. New Phytol. 133 273–280. 10.1111/j.1469-8137.1996.tb01894.x PubMed DOI

Baldrian P., Kolařík M., Štursová M., Kopecký J., Valášková V., Větrovský T., et al. (2012). Active and total microbial communities in forest soil are largely different and highly stratified during decomposition. ISME J. 6 248–258. 10.1038/ismej.2011.95 PubMed DOI PMC

Baltruschat H. (1987). Field inoculation of maize with vesicular-arbuscular mycorrhizal fungi by using expanded clay as carrier material for mycorrhiza. J. Plant Dis. Protect. 94 419–430.

Beier S., Bertilsson S. (2013). Bacterial chitin degradation-mechanisms and ecophysiological strategies. Front. Microbiol. 4:149 10.3389/Fmicb.2013.00149 PubMed DOI PMC

Bonkowski M. (2004). Protozoa and plant growth: the microbial loop in soil revisited. New Phytol. 162 617–631. 10.1111/j.1469-8137.2004.01066.x PubMed DOI

Calvet C., Camprubi A., Perez-Hernandez A., Lovato P. E. (2013). Plant growth stimulation and root colonization potential of in vivo versus in vitro arbuscular mycorrhizal inocula. Hortscience 48 897–901.

Cavagnaro T. R., Smith F. A., Smith S. E., Jakobsen I. (2005). Functional diversity in arbuscular mycorrhizas: exploitation of soil patches with different phosphate enrichment differs among fungal species. Plant Cell Environ. 28 642–650. 10.1111/j.1365-3040.2005.01310.x DOI

Cheng L., Booker F. L., Tu C., Burkey K. O., Zhou L. S., Shew H. D., et al. (2012). Arbuscular mycorrhizal fungi increase organic carbon decomposition under elevated CO2. Science 337 1084–1087. 10.1126/science.1224304 PubMed DOI

Couillerot O., Ramirez-Trujillo A., Walker V., von Felten A., Jansa J., Maurhofer M., et al. (2013). Comparison of prominent Azospirillum strains in Azospirillum-Pseudomonas-Glomus consortia for promotion of maize growth. Appl. Microbiol. Biot. 97 4639–4649. 10.1007/s00253-012-4249-z PubMed DOI

Cox G., Tinker P. B. (1976). Translocation and transfer of nutrients in vesicular-arbuscular mycorrhizas. I. The arbuscule and phosphorus transfer: a quantitative ultrastructural study. New Phytol. 77 371–378. 10.1111/j.1469-8137.1976.tb01526.x DOI

Cruz C., Egsgaard H., Trujillo C., Ambus P., Requena N., Martins-Loucao M. A., et al. (2007). Enzymatic evidence for the key role of arginine in nitrogen translocation by arbuscular mycorrhizal fungi. Plant Physiol. 144 782–792. 10.1104/pp.106.090522 PubMed DOI PMC

Drigo B., Pijl A. S., Duyts H., Kielak A., Gamper H. A., Houtekamer M. J., et al. (2010). Shifting carbon flow from roots into associated microbial communities in response to elevated atmospheric CO2. Proc. Natl. Acad. Sci. U.S.A. 107 10938–10942. 10.1073/pnas.0912421107 PubMed DOI PMC

Facelli E., Facelli J. M. (2002). Soil phosphorus heterogeneity and mycorrhizal symbiosis regulate plant intra-specific competition and size distribution. Oecologia 133 54–61. 10.1007/s00442-002-1022-5 PubMed DOI

Felderer B., Jansa J., Schulin R. (2013). Interaction between root growth allocation and mycorrhizal fungi in soil with patchy P distribution. Plant Soil 373 569–582. 10.1007/s11104-013-1818-6 DOI

Feldmann F., Idczak E. (1992). “Inoculum production of vesicular-arbuscular mycorrhizal fungi for use in tropical nurseries,” in Methods in Microbiology eds Norris J. R., Read D. J., Varma A. K. (London: Academic Press; ) 339–357.

Fellbaum C. R., Gachomo E. W., Beesetty Y., Choudhari S., Strahan G. D., Pfeffer P. E., et al. (2012). Carbon availability triggers fungal nitrogen uptake and transport in arbuscular mycorrhizal symbiosis. Proc. Natl. Acad. Sci. U.S.A. 109 2666–2671. 10.1073/pnas.1118650109 PubMed DOI PMC

Feng G., Song Y. C., Li X. L., Christie P. (2003). Contribution of arbuscular mycorrhizal fungi to utilization of organic sources of phosphorus by red clover in a calcareous soil. Appl. Soil Ecol. 22 139–148. 10.1016/S0929-1393(02)00133-6 DOI

Feng H., Feng G., Wang J., Li X. (2004). Effect of sodium phytate on alkaline phosphatase (ALP) activity in intraradical hyphae of AM fungi and development of its extraradical hyphae. Yingyong Shengtai Xuebao 15 1009–1013. PubMed

Fitter A. H. (1991). Costs and benefits of mycorrhizas - Implications for functioning under natural conditions. Experientia 47 350–355. 10.1007/Bf01972076 DOI

Gavito M. E., Olsson P. A. (2003). Allocation of plant carbon to foraging and storage in arbuscular mycorrhizal fungi. FEMS Microbiol. Ecol. 45 181–187. 10.1016/S0168-6496(03)00150-158 PubMed DOI

Gavito M. E., Olsson P. A. (2008). Foraging strategies of the external mycelium of the arbuscular mycorrhizal fungi Glomus intraradices and Scutellospora calospora. Appl. Soil Ecol. 39 282–290. 10.1016/j.apsoil.2008.01.001 DOI

George T., Singleton P. W., Vankessel C. (1993). The use of 15N natural abundance and nitrogen yield of nonnodulating isolines to estimate nitrogen fixation by soybeans (Glycine max L) across 3 elevations. Biol. Fertil. Soils 15 81–86. 10.1007/Bf00336422 DOI

Govindarajulu M., Pfeffer P. E., Jin H. R., Abubaker J., Douds D. D., Allen J. W., et al. (2005). Nitrogen transfer in the arbuscular mycorrhizal symbiosis. Nature 435 819–823. 10.1038/Nature03610 PubMed DOI

Gryndler M., Hršelová H., Stříteská D. (2000). Effect of soil bacteria on hyphal growth of the arbuscular mycorrhizal fungus Glomus claroideum. Folia Microbiol. 45 545–551. 10.1007/Bf02818724 PubMed DOI

Gryndler M., Jansa J., Hršelová H., Chvátalová I., Vosátka M. (2003). Chitin stimulates development and sporulation of arbuscular mycorrhizal fungi. Appl. Soil Ecol. 22 283–287. 10.1016/S0929-1393(02)00154-3 DOI

Gryndler M., Vejsadová H., Vančura V. (1992). The effect of magnesium ions on the vesicular arbuscular mycorrhizal infection of maize roots. New Phytol. 122 455–460. 10.1111/j.1469-8137.1992.tb00073.x PubMed DOI

Gryndler M., Vosátka M., Hršelová H., Chvátalová I., Jansa J. (2002). Interaction between arbuscular mycorrhizal fungi and cellulose in growth substrate. Appl. Soil Ecol. 19 279–288. 10.1016/S0929-1393(02)00004-5 DOI

Herman D. J., Firestone M. K., Nuccio E., Hodge A. (2012). Interactions between an arbuscular mycorrhizal fungus and a soil microbial community mediating litter decomposition. FEMS Microbiol. Ecol. 80 236–247. 10.1111/j.1574-6941.2011.01292.x PubMed DOI

Hodge A. (2004). The plastic plant: root responses to heterogeneous supplies of nutrients. New Phytol. 162 9–24. 10.1111/j.1469-8137.2004.01015.x DOI

Hodge A., Campbell C. D., Fitter A. H. (2001). An arbuscular mycorrhizal fungus accelerates decomposition and acquires nitrogen directly from organic material. Nature 413 297–299. 10.1038/35095041 PubMed DOI

Hodge A., Fitter A. H. (2010). Substantial nitrogen acquisition by arbuscular mycorrhizal fungi from organic material has implications for N cycling. Proc. Natl. Acad. Sci. U.S.A. 107 13754–13759. 10.1073/pnas.1005874107 PubMed DOI PMC

Hodge A., Robinson D., Fitter A. H. (2000). Arbuscular mycorrhizal inoculum enhances root proliferation in, but not nitrogen capture from, nutrient-rich patches in soil. New Phytol. 145 575–584. 10.1046/j.1469-8137.2000.00602.x PubMed DOI

Hodge A., Storer K. (2015). Arbuscular mycorrhiza and nitrogen: implications for individual plants through to ecosystems. Plant Soil 386 1–19. 10.1007/s11104-014-2162-1 DOI

Jakobsen I., Abbott L. K., Robson A. D. (1992). External hyphae of vesicular-arbuscular mycorrhizal fungi associated with Trifolium subterraneum L.1. Spread of hyphae and phosphorus inflow into roots. New Phytol. 120 371–380. 10.1111/j.1469-8137.1992.tb01077.x DOI

Jansa J., Bukovská P., Gryndler M. (2013). Mycorrhizal hyphae as ecological niche for highly specialized hypersymbionts - or just soil free-riders? Front. Plant Sci. 4:134 10.3389/Fpls.2013.00134 PubMed DOI PMC

Jansa J., Gryndler M. (2010). “Biotic environment of the arbuscular mycorrhizal fungi in soil,” in Arbuscular Mycorrhizas: Physiology and Function eds Koltai H., Kapulnik Y. (Dordrecht, NL: Springer; ) 209–236. 10.1007/978-90-481-9489-6_10 DOI

Jansa J., Mozafar A., Frossard E. (2003). Long-distance transport of P and Zn through the hyphae of an arbuscular mycorrhizal fungus in symbiosis with maize. Agronomie 23 481–488. 10.1051/Agro:2003013 DOI

Jansa J., Mozafar A., Frossard E. (2005). Phosphorus acquisition strategies within arbuscular mycorrhizal fungal community of a single field site. Plant Soil 276 163–176. 10.1007/s11104-005-4274-0 DOI

Johnson N. C., Wilson G. W. T., Wilson J. A., Miller R. M., Bowker M. A. (2015). Mycorrhizal phenotypes and the law of the minimum. New Phytol. 205 1473–1484. 10.1111/nph.13172 PubMed DOI

Joner E. J., Jakobsen I. (1995). Growth and extracellular phosphatase activity of arbuscular mycorrhizal hyphae as influenced by soil organic matter. Soil Biol. Biochem. 27 1153–1159. 10.1016/0038-0717(95)00047-I DOI

Joner E. J., van Aarle I. M., Vosátka M. (2000). Phosphatase activity of extra-radical arbuscular mycorrhizal hyphae: a review. Plant Soil 226 199–210. 10.1023/A:1026582207192 DOI

Koide R. T., Kabir Z. (2000). Extraradical hyphae of the mycorrhizal fungus Glomus intraradices can hydrolyse organic phosphate. New Phytol. 148 511–517. 10.1046/j.1469-8137.2000.00776.x PubMed DOI

Koller R., Scheu S., Bonkowski M., Robin C. (2013). Protozoa stimulate N uptake and growth of arbuscular mycorrhizal plants. Soil Biol. Biochem. 65 204–210. 10.1016/j.soilbio.2013.05.020 DOI

Konvalinková T., Püschel D., Janoušková M., Gryndler M., Jansa J. (2015). Duration and intensity of shade differentially affects mycorrhizal growth- and phosphorus uptake responses of Medicago truncatula. Front. Plant Sci. 6:65 10.3389/Fpls.2015.00065 PubMed DOI PMC

Koske R. E., Gemma J. N. (1989). A modified procedure for staining roots to detect VA mycorrhizas. Mycol. Res. 92 486–505. 10.1016/S0953-7562(89)80195-9 DOI

Kowalchuk G. A., Stephen J. R., DeBoer W., Prosser J. I., Embley T. M., Woldendorp J. W. (1997). Analysis of ammonia-oxidizing bacteria of the beta subdivision of the class Proteobacteria in coastal sand dunes by denaturing gradient gel electrophoresis and sequencing of PCR-amplified 16S ribosomal DNA fragments. Appl. Environ. Microb. 63 1489–1497. PubMed PMC

Leigh J., Fitter A. H., Hodge A. (2011). Growth and symbiotic effectiveness of an arbuscular mycorrhizal fungus in organic matter in competition with soil bacteria. FEMS Microbiol. Ecol. 76 428–438. 10.1111/j.1574-6941.2011.01066.x PubMed DOI

Leigh J., Hodge A., Fitter A. H. (2009). Arbuscular mycorrhizal fungi can transfer substantial amounts of nitrogen to their host plant from organic material. New Phytol. 181 199–207. 10.1111/j.1469-8137.2008.02630.x PubMed DOI

Li X. L., George E., Marschner H. (1991). Extension of the phosphorus depletion zone in VA mycorrhizal white clover in a calcareous soil. Plant Soil 136 41–48. 10.1007/Bf02465218 DOI

Mäder P., Vierheilig H., Streitwolf-Engel R., Boller T., Frey B., Christie P., et al. (2000). Transport of 15N from a soil compartment separated by a polytetrafluoroethylene membrane to plant roots via the hyphae of arbuscular mycorrhizal fungi. New Phytol. 146 155–161. 10.1046/j.1469-8137.2000.00615.x DOI

McGonigle T. P., Miller M. H., Evans D. G., Fairchild G. L., Swan J. A. (1990). A new method which gives an objective measure of colonization of roots by vesicular-arbuscular mycorrhizal fungi. New Phytol. 115 495–501. 10.1111/j.1469-8137.1990.tb00476.x PubMed DOI

Nuccio E. E., Hodge A., Pett-Ridge J., Herman D. J., Weber P. K., Firestone M. K. (2013). An arbuscular mycorrhizal fungus significantly modifies the soil bacterial community and nitrogen cycling during litter decomposition. Environ. Microbiol. 15 1870–1881. 10.1111/1462-2920.12081 PubMed DOI

Ohno T., Zibilske L. M. (1991). Determination of low concentrations of phosphorus in soil extracts using Malachite green. Soil Sci. Soc. Am. J. 55 892–895. 10.2136/sssaj1991.03615995005500030046x DOI

Ravnskov S., Larsen J., Olsson P. A., Jakobsen I. (1999). Effects of various organic compounds growth and phosphorus uptake of an arbuscular mycorrhizal fungus. New Phytol. 141 517–524. 10.1046/j.1469-8137.1999.00353.x DOI

Robinson D. (1996). Resource capture by localized root proliferation: why do plants bother? Ann. Bot. Lond. 77 179–185. 10.1006/anbo.1996.0020 DOI

Robson A. D., Longnecker N. E., Osborne L. D. (1992). Effects of heterogeneous nutrient supply on root growth and nutrient uptake in relation to nutrient supply on duplex soils. Aust. J. Exp. Agric. 32 879–886. 10.1071/Ea9920879 DOI

Rotthauwe J. H., Witzel K. P., Liesack W. (1997). The ammonia monooxygenase structural gene amoA as a functional marker: molecular fine-scale analysis of natural ammonia-oxidizing populations. Appl. Environ. Microb. 63 4704–4712. PubMed PMC

Scheublin T. R., Ridgway K. P., Young J. P. W., van der Heijden M. G. A. (2004). Nonlegumes, legumes, and root nodules harbor different arbuscular mycorrhizal fungal communities. Appl. Environ. Microb. 70 6240–6246. 10.1128/Aem.70.10.6240-6246.2004 PubMed DOI PMC

Šmilauer P., Lepš J. (2014). Multivariate Analysis of Ecological Data using Canoco 5. Cambridge: Cambridge University Press.

Smith S. E., Smith F. A., Jakobsen I. (2004). Functional diversity in arbuscular mycorrhizal (AM) symbioses: the contribution of the mycorrhizal P uptake pathway is not correlated with mycorrhizal responses in growth or total P uptake. New Phytol. 162 511–524. 10.1111/j.1469-8137.2004.01039.x DOI

Somasegaran P., Hoben H. J. (1994). Handbook for Rhizobia: Methods in Legume-Rhizobium Technology. New York, NY: Springer.

St. John T., Coleman D., Reid C. (1983). Association of vesicular-arbuscular mycorrhizal hyphae with soil organic particles. Ecology 64 957–959. 10.2307/1937216 DOI

Sulieman S., Van Ha C., Schulze J., Tran L. S. P. (2013). Growth and nodulation of symbiotic Medicago truncatula at different levels of phosphorus availability. J. Exp. Bot. 64 2701–2712. 10.1093/jxb/ert122 PubMed DOI PMC

Sylvia D. M., Norris J. R. (1992). “Quantification of external hyphae of vesicular-arbuscular mycorrhizal fungi,” in Methods in Microbiology eds Read D. J., Varma A. K. (London: Academic Press; ) 53–65.

Tarafdar J. C., Marschner H. (1994). Phosphatase activity in the rhizosphere and hyphosphere of VA mycorrhizal wheat supplied with inorganic and organic Posphorus. Soil Biol. Biochem. 26 387–395. 10.1016/0038-0717(94)90288-7 DOI

Ter Braak C. J. F., Šmilauer P. (2002). Canoco 4.5. Reference Manual. Wageningen, NL: Biometris.

Thonar C., Erb A., Jansa J. (2012). Real-time PCR to quantify composition of arbuscular mycorrhizal fungal communities - marker design, verification, calibration and field validation. Mol. Ecol. Res. 12 219–232. 10.1111/j.1755-0998.2011.03086.x PubMed DOI

Thonar C., Schnepf A., Frossard E., Roose T., Jansa J. (2011). Traits related to differences in function among three arbuscular mycorrhizal fungi. Plant Soil 339 231–245. 10.1007/s11104-010-0571-3 DOI

Toljander J. F., Artursson V., Paul L. R., Jansson J. K., Finlay R. D. (2006). Attachment of different soil bacteria to arbuscular mycorrhizal fungal extraradical hyphae is determined by hyphal vitality and fungal species. FEMS Microbiol. Lett. 254 34–40. 10.1111/j.1574-6968.2005.00003.x PubMed DOI

Toljander J. F., Lindahl B. D., Paul L. R., Elfstrand M., Finlay R. D. (2007). Influence of arbuscular mycorrhizal mycelial exudates on soil bacterial growth and community structure. FEMS Microbiol. Ecol. 61 295–304. 10.1111/j.1574-6941.2007.00337.x PubMed DOI

van der Heijden M. G. A., Martin F. M., Selosse M. A., Sanders I. R. (2015). Mycorrhizal ecology and evolution: the past, the present, and the future. New Phytol. 205 1406–1423. 10.1111/Nph.13288 PubMed DOI

Větrovský T., Baldrian P. (2013). Analysis of soil fungal communities by amplicon pyrosequencing: current approaches to data analysis and the introduction of the pipeline SEED. Biol. Fertil. Soils 49 1027–1037. 10.1007/s00374-013-0801-y DOI

Wagg C., Bender S. F., Widmer F., van der Heijden M. G. A. (2014). Soil biodiversity and soil community composition determine ecosystem multifunctionality. Proc. Natl. Acad. Sci. U.S.A. 111 5266–5270. 10.1073/pnas.1320054111 PubMed DOI PMC

Watt M., Silk W. K., Passioura J. B. (2006). Rates of root and organism growth, soil conditions, and temporal and spatial development of the rhizosphere. Ann. Bot. London 97 839–855. 10.1093/Aob/Mc1028 PubMed DOI PMC

Webster G., Embley T. M., Freitag T. E., Smith Z., Prosser J. I. (2005). Links between ammonia oxidizer species composition, functional diversity and nitrification kinetics in grassland soils. Environ. Microbiol. 7 676–684. 10.1111/j.1462-2920.2005.00740.x PubMed DOI

White T., Bruns T., Lee S., Taylor J. (1990). “Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics,” in PCR Protocols: A Guide to Methods and Applications eds Innis M. A., Gelfand D. H., Sninsky J. J., White T. J. (San Diego CA: Academic Press; ) 315–322.

Zhang L., Fan J. Q., Ding X. D., He X. H., Zhang F. S., Feng G. (2014). Hyphosphere interactions between an arbuscular mycorrhizal fungus and a phosphate solubilizing bacterium promote phytate mineralization in soil. Soil Biol. Biochem. 74 177–183. 10.1016/j.soilbio.2014.03.004 DOI

Zheng C., Chai M., Jiang S., Zhang S., Christie P., Zhang J. (2015). Foraging capability of extraradical mycelium of arbuscular mycorrhizal fungi to soil phosphorus patches and evidence of carry-over effect on new host plant. Plant Soil 387 201–217. 10.1007/s11104-014-2286-3 DOI

Unraveling the diversity of hyphal explorative traits among Rhizophagus irregularis genotypes

Arbuscular mycorrhizal fungi suppress ammonia-oxidizing bacteria but not archaea across agricultural soils

Nutrient-dependent cross-kingdom interactions in the hyphosphere of an arbuscular mycorrhizal fungus

Arbuscular mycorrhiza can be disadvantageous for weedy annuals in competition with paired perennial plants

Arbuscular Mycorrhiza and Nitrification: Disentangling Processes and Players by Using Synthetic Nitrification Inhibitors

Arbuscular Mycorrhiza Mediates Efficient Recycling From Soil to Plants of Nitrogen Bound in Chitin

Arbuscular mycorrhizal fungi favor invasive Echinops sphaerocephalus when grown in competition with native Inula conyzae

Soil Matrix Determines the Outcome of Interaction Between Mycorrhizal Symbiosis and Biochar for Andropogon gerardii Growth and Nutrition

Utilization of organic nitrogen by arbuscular mycorrhizal fungi-is there a specific role for protists and ammonia oxidizers?