Abstract
Long-term symbiotic associations often lead to reciprocal adaptation between the involved entities. One of the main challenges for studies of such symbioses is differentiating adaptation from neutral processes and phylogenetic background. Ambrosia fungi, cultivated by ambrosia beetles as their sole food source, provide an excellent model to study evolutionary adaptation in a comparative framework because they evolved many times, and each origin bears features seemingly convergently adapted to the symbiosis. We tested whether the symbiotic lifestyle of unrelated ambrosia fungi has led to convergence in the key feature of the symbiotic phenotype—nutrition provisioning to the vector beetles. We compared conidia and mycelium content in three phylogenetic pairs of ambrosia fungi and their closely related nonambrosia relatives using an untargeted metabolomic assay. Multivariate analysis of 311 polar metabolites and 14063 lipid features revealed no convergence of nutrient content across ambrosia lineages. Instead, most variation of the metabolome composition was explained by phylogenetic relationships among the fungi. Thus the overall metabolome evolution of each ambrosia fungus is mostly driven by its inherited metabolism rather than the transition toward symbiosis. We identified eight candidate lipid compounds with expression levels different between the swollen ambrosia spores and other tissues, but they were not consistently elevated across ambrosia fungi. We conclude that ambrosia provisions consist either of nonspecific nutrients in elevated amounts, or of metabolites that are specific to each of the ambrosia symbioses.
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References
Douglas AE. Nutritional interactions in insect-microbial symbioses: aphids and their symbiotic bacteria Buchnera. Annu Rev Entomol. 1998;43:17–37.
Brownlie JC, Johnson KN. Symbiont-mediated protection in insect hosts. Trends Microbiol. 2009;17:348–54.
Six DL. Ecological and evolutionary determinants of bark beetle—fungus symbioses. Insects. 2012;3:339–66.
Mueller UG, Gerardo NM, Aanen DK, Six DL, Schultz TR. The evolution of agriculture in insects. Annu Rev Ecol Evol S. 2005;36:563–95.
Wermelinger B, Thomsen IM. The woodwasp Sirex noctilio and its associated fungus Amylostereum areolatum in Europe. In: Slippers B, de Groot P, Wingfield MJ editors. The sirex woodwasp and its fungal symbiont: research and management of a worldwide invasive pest. Dordrecht: Springer; 2012. pp. 65–80.
Moran NA. Symbiosis as an adaptive process and source of phenotypic complexity. PNAS. 2007;104:8627–33.
Batra LR, Michie MD. Pleomorphism in some ambrosia and related fungi. Trans Kans Acad Sci. 1963;66:470–81.
Quinlan RJ, Cherrett JM. The role of fungus in the diet of the leaf-cutting ant Atta cephalotes (L.). Ecol Entomol. 1979;4:151–60.
Leuthold RH, Badertscher S, Imboden H. The inoculation of newly formed fungus comb with Termitomyces in Macrotermes colonies (Isoptera, Macrotermitinae). Ins Soc. 1989;36:328–38.
Ayres MP, Wilkens RT, Ruel JJ, Lombardero MJ, Vallery E. Nitrogen budgets of phloem-feeding bark beetles with and without symbiotic fungi. Ecology. 2000;81:2198–210.
Hyodo F, Tayasu I, Inoue T, Azuma J-I, Kudo T, Abe T. Differential role of symbiotic fungi in lignin degradation and food provision for fungus-growing termites (Macrotermitinae: Isoptera). Funct Ecol. 2003;17:186–93.
Schiøtt M, Rogowska-Wrzesinska A, Roepstorff P, Boomsma JJ. Leaf-cutting ant fungi produce cell wall degrading pectinase complexes reminiscent of phytopathogenic fungi. BMC Biol. 2010;8:156.
Nobre T, Rouland-Lefèvre C, Aanen DK. Comparative biology of fungus cultivation in termites and ants. In: Bignell DE, Roisin Y, Lo N editors. Biology of termites: a modern synthesis. Dordrecht: Springer; 2011. pp. 193–210.
Suen G, Teiling C, Li L, Holt C, Abouheif E, Bornberg-Bauer E, et al. The genome sequence of the leaf-cutter ant Atta cephalotes reveals insights into its obligate symbiotic lifestyle. PLoS Genet. 2011;7:e1002007.
Bracewell RR, Six DL. Experimental evidence of bark beetle adaptation to a fungal symbiont. Ecol Evol. 2015;5:5109–19.
Massoumi Alamouti S, Tsui CK, Breuil C. Multigene phylogeny of filamentous ambrosia fungi associated with ambrosia and bark beetles. Mycol Res. 2009;113:822–35.
Jordal BH, Cognato AI. Molecular phylogeny of bark and ambrosia beetles reveals multiple origins of fungus farming during periods of global warming. Bmc Evol Biol. 2012;12:133.
Nygaard S, Hu H, Li C, Schiøtt M, Chen Z, Yang Z, et al. Reciprocal genomic evolution in the ant–fungus agricultural symbiosis. Nat Commun. 2016;7:ncomms12233.
Wood SL. Bark and ambrosia beetles of South America (Coleoptera, Scolytidae). In: Monte L editor. Provo, Utah: Bean Life Science Museum; 2007.
Johnson AJ, McKenna DD, Jordal BH, Cognato AI, Smith SM, Lemmon AR, et al. Phylogenomics clarifies repeated evolutionary origins of inbreeding and fungus farming in bark beetles (Curculionidae, Scolytinae). Mol Phylogenet Evol. 2018;127:229–38.
Li Y, Simmons DR, Bateman CC, Short DPG, Kasson MT, Rabaglia RJ, et al. New fungus-insect symbiosis: culturing, molecular, and histological methods determine saprophytic polyporales mutualists of Ambrosiodmus ambrosia beetles. PLoS ONE. 2015;10:e0137689.
Hulcr J, Stelinski LL. The ambrosia symbiosis: from evolutionary ecology to practical management. Annu Rev Entomol. 2017;62:285–303.
Kasson MT, Wickert KL, Stauder CM, Macias AM, Berger MC, Simmons DR, et al. Mutualism with aggressive wood-degrading Flavodon ambrosius (Polyporales) facilitates niche expansion and communal social structure in Ambrosiophilus ambrosia beetles. Fungal Ecol. 2016;23:86–96.
De Fine Licht HH, Biedermann PHW. Patterns of functional enzyme activity in fungus farming ambrosia beetles. Front Zool. 2012;9:13.
Huang Y-T, Skelton J, Hulcr J. Multiple evolutionary origins lead to diversity in the metabolic profiles of ambrosia fungi. Fungal Ecol. 2019;38:80–8.
Norris DM, Baker JM, Chu HM. Symbiontic interrelationships between microbes and ambrosia beetles. III. Ergosterol as the source of sterol to the insect. Ann Entomol Soc Am. 1969;62:413–4.
Kok LT, Norris DM, Chu HM. Sterol metabolism as a basis for a mutualistic symbiosis. Nature. 1970;225:661–2.
Morales-Ramos JA, Rojas MG, Sittertz-Bhatkar H, Saldaña G. Symbiotic relationship between Hypothenemus hampei (Coleoptera: Scolytidae) and Fusarium solani (Moniliales: Tuberculariaceae). Ann Entomol Soc Am. 2000;93:541–7.
Bentz BJ, Six DL. Ergosterol content of fungi associated with Dendroctonus ponderosae and Dendroctonus rufipennis (Coleoptera: Curculionidae, Scolytinae). Ann Entomol Soc Am. 2006;99:189–94.
Guijas C, Montenegro-Burke JR, Domingo-Almenara X, Palermo A, Warth B, Hermann G, et al. METLIN: a technology platform for identifying knowns and unknowns. Anal Chem. 2018;90:3156–64.
Fahy E, Sud M, Cotter D, Subramaniam S. LIPID MAPS online tools for lipid research. Nucleic Acids Res. 2007;35:W606–12.
Oksanen J, Blanchet FG, Kindt R, Legendre P, Minchin PR, O’hara R, et al. vegan: Community ecology package, R package version 2. 2013.
Anderson MJ. Distance-based tests for homogeneity of multivariate dispersions. Biometrics. 2006;62:245–53.
Schliep KP. phangorn: phylogenetic analysis in R. Bioinformatics. 2011;27:592–3.
Paradis E, Claude J, Strimmer K. APE: analyses of phylogenetics and evolution in R language. Bioinformatics. 2004;20:289–90.
Diniz-Filho JAF, Bini LM, Rangel TF, Morales-Castilla I, Olalla-Tárraga MÁ, Rodríguez MÁ, et al. On the selection of phylogenetic eigenvectors for ecological analyses. Ecography. 2012;35:239–49.
Tedersoo L, Mett M, Ishida TA, Bahram M. Phylogenetic relationships among host plants explain differences in fungal species richness and community composition in ectomycorrhizal symbiosis. N Phytol. 2013;199:822–31.
Blanchet FG, Legendre P, Borcard D. Forward selection of explanatory variables. Ecology. 2008;89:2623–32.
Dray S, Legendre P, Blanchet G. packfor: Forward Selection with permutation (Canoco p. 46). R package version 00-7/r58. 2009.
Storey JD, Tibshirani R. Statistical significance for genomewide studies. PNAS. 2003;100:9440–5.
Dabney A, Storey JD, Warnes GR. qvalue: Q-value estimation for false discovery rate control. R package version 2. 2010.
Kolde R. Pheatmap: pretty heatmaps. R package version. 2012;61:617.
Li Y, Ruan Y-Y, Stanley EL, Skelton J, Hulcr J. Plasticity of mycangia in Xylosandrus ambrosia beetles. Insect Sci. 2019;26:732–42.
Botha WJ, Eicker A. Nutritional value of Termitomyces mycelial protein and growth of mycelium on natural substrates. Mycol Res. 1992;96:350–4.
Boa E. Wild Edible Fungi: A Global Overview of Their Use and Importance to People. Daya Publishing House; 2004.
Saucedo-Carabez JR, Ploetz RC, Konkol JL, Carrillo D, Gazis R. Partnerships Between Ambrosia Beetles and Fungi: Lineage-Specific Promiscuity Among Vectors of the Laurel Wilt Pathogen, Raffaelea lauricola. Microb Ecol. 2018;76:925–40.
Bittman R. Glycerolipids: chemistry. In: Roberts GCK, editor. Encyclopedia of biophysics. Springer: Heidelberg, Berlin; 2013. pp. 907–14.
Singh A, Del Poeta M. Sphingolipidomics: An Important Mechanistic Tool for Studying Fungal Pathogens. Front Microbiol. 2016;7:501.
Chaleckis R, Meister I, Zhang P, Wheelock CE. Challenges, progress and promises of metabolite annotation for LC–MS-based metabolomics. Curr Opin Biotech. 2019;55:44–50.
Schwadorf K, Müller HM. Determination of ergosterol in cereals, mixed feed components, and mixed feeds by liquid chromatography. J Assoc Anal Chem. 1989;72:457–62.
Clayton RB. The utilization of sterols by insects. J Lipid Res. 1964;5:3–19.
Pasanen A-L, Yli-Pietilä K, Pasanen P, Kalliokoski P, Tarhanen J. Ergosterol content in various fungal species and biocontaminated building materials. Appl Environ Microbiol. 1999;65:138–42.
Baker JM, Norris DM. A complex of fungi mutualistically involved in the nutrition of the ambrosia beetle Xyleborus ferrugineus. J Invertebr Pathol. 1968;11:246–50.
Fraedrich SW, Harrington TC, Rabaglia RJ, Ulyshen MD, Mayfield AE, Hanula JL, et al. A fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in redbay and other Lauraceae in the southeastern United States. Plant Dis. 2008;92:215–24.
Mendel Z, Protasov A, Sharon M, Zveibil A, Yehuda SB, O’Donnell K, et al. An Asian ambrosia beetle Euwallacea fornicatus and its novel symbiotic fungus Fusarium sp. pose a serious threat to the Israeli avocado industry. Phytoparasitica. 2012;40:235–8.
Acknowledgements
The authors thank Adam Wong for suggestions regarding the metabolomic analysis. This project was partially funded by the U.S. Forest Service, U.S. Department of Agriculture—Animal and Plant Health Inspection Service (USDA APHIS) and the National Science Foundation. The UF Mass Spectrometry Research and Education Center was funded by NIH grant S10 OD021758-01A1.
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Huang, YT., Skelton, J. & Hulcr, J. Lipids and small metabolites provisioned by ambrosia fungi to symbiotic beetles are phylogeny-dependent, not convergent. ISME J 14, 1089–1099 (2020). https://doi.org/10.1038/s41396-020-0593-7
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DOI: https://doi.org/10.1038/s41396-020-0593-7
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