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Queiroz RRS, Teodoro TBP, Carolino AT, Bitencourt ROB, Souza WG, Boechat MSB, Sobrinho RR, Silva GA, Samuels RI. Production of Escovopsis conidia and the potential use of this parasitic fungus as a biological control agent of leaf-cutting ant fungus gardens. Arch Microbiol 2024; 206:128. [PMID: 38416227 DOI: 10.1007/s00203-024-03862-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/14/2024] [Accepted: 01/23/2024] [Indexed: 02/29/2024]
Abstract
This study was carried out to investigate the use of different substrates for the production of Escovopsis conidia and verify the virulence of four different isolates cultured on four types of substrates using a novel bioassay. Escovopsis isolates were molecularly identified, based on Internal Transcribed Spacer (ITS) nucleotide sequences. To evaluate conidial production, suspensions (1 × 106 conidia mL-1) of each Escovopsis isolate were inoculated onto four substrates (parboiled rice, white rice, rolled oats, and corn grits). After 14 days, conidial yields were assessed. The virulence of each isolate cultured on the four substrates was tested against Leucoagaricus fungus garden fragments, by directly applying 500 µL of each conidial suspension (1 × 107 conidia mL-1), and the development of the parasite was monitored daily until it completely colonized the fungus garden. It was observed that rolled oats were the best substrate for conidial production, with a yield of 1.7 × 107 to 2.0 × 108 conidia mL-1. Furthermore, isolate AT-01 produced the highest number of conidia when compared with the other isolates. Regardless of the substrate used to produce AT-01 conidia, this isolate completely colonized the fungus garden 6 days post inoculation (dpi), followed by AT-02, AC-01, and AC-2. High levels of both conidial production and virulence against the leaf-cutting ant fungus garden were observed here.
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Affiliation(s)
- Raymyson R S Queiroz
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Thais B P Teodoro
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Aline T Carolino
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Ricardo O B Bitencourt
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Willians G Souza
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Marcela S B Boechat
- Laboratório Melhoramento Genético Vegetal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Roberto R Sobrinho
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Gerson A Silva
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil
| | - Richard I Samuels
- Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil.
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2
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Pietrobon TDC, Kooij PW, Montoya QV, Rodrigues A. Escovopsioides nivea is a non-specific antagonistic symbiont of ant-fungal crops. FUNGAL ECOL 2022. [DOI: 10.1016/j.funeco.2022.101140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Interactions among Escovopsis, Antagonistic Microfungi Associated with the Fungus-Growing Ant Symbiosis. J Fungi (Basel) 2021; 7:jof7121007. [PMID: 34946990 PMCID: PMC8703566 DOI: 10.3390/jof7121007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 11/17/2022] Open
Abstract
Fungi in the genus Escovopsis (Ascomycota: Hypocreales) are prevalent associates of the complex symbiosis between fungus-growing ants (Tribe Attini), the ants' cultivated basidiomycete fungi and a consortium of both beneficial and harmful microbes found within the ants' garden communities. Some Escovopsis spp. have been shown to attack the ants' cultivated fungi, and co-infections by multiple Escovopsis spp. are common in gardens in nature. Yet, little is known about how Escovopsis strains impact each other. Since microbe-microbe interactions play a central role in microbial ecology and evolution, we conducted experiments to assay the types of interactions that govern Escovopsis-Escovopsis relationships. We isolated Escovopsis strains from the gardens of 10 attine ant genera representing basal (lower) and derived groups in the attine ant phylogeny. We conducted in vitro experiments to determine the outcome of both intraclonal and interclonal Escovopsis confrontations. When paired with self (intraclonal interactions), Escovopsis isolated from lower attine colonies exhibited antagonistic (inhibitory) responses, while strains isolated from derived attine colonies exhibited neutral or mutualistic interactions, leading to a clear phylogenetic pattern of interaction outcome. Interclonal interactions were more varied, exhibiting less phylogenetic signal. These results can serve as the basis for future studies on the costs and benefits of Escovopsis coinfection, and on the genetic and chemical mechanisms that regulate the compatibility and incompatibility observed here.
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Montoya QV, Martiarena MJS, Bizarria R, Gerardo NM, Rodrigues A. Fungi inhabiting attine ant colonies: reassessment of the genus Escovopsis and description of Luteomyces and Sympodiorosea gens. nov. IMA Fungus 2021; 12:23. [PMID: 34429165 PMCID: PMC8383443 DOI: 10.1186/s43008-021-00078-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 08/10/2021] [Indexed: 11/15/2022] Open
Abstract
Escovopsis is a diverse group of fungi, which are considered specialized parasites of the fungal cultivars of fungus-growing ants. The lack of a suitable taxonomic framework and phylogenetic inconsistencies have long hampered Escovopsis research. The aim of this study is to reassess the genus Escovopsis using a taxonomic approach and a comprehensive multilocus phylogenetic analysis, in order to set the basis of the genus systematics and the stage for future Escovopsis research. Our results support the separation of Escovopsis into three distinct genera. In light of this, we redefine Escovopsis as a monophyletic clade whose main feature is to form terminal vesicles on conidiophores. Consequently, E. kreiselii and E. trichodermoides were recombined into two new genera, Sympodiorosea and Luteomyces, as S. kreiselii and L. trichodermoides, respectively. This study expands our understanding of the systematics of Escovopsis and related genera, thereby facilitating future research on the evolutionary history, taxonomic diversity, and ecological roles of these inhabitants of the attine ant colonies.
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Affiliation(s)
- Quimi Vidaurre Montoya
- Department of General and Applied Biology, São Paulo State University (UNESP), Avenida 24-A, n. 1515, Bela Vista, Rio Claro, SP, 13.506-900, Brazil. .,Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, SP, Brazil.
| | - Maria Jesus Sutta Martiarena
- Department of General and Applied Biology, São Paulo State University (UNESP), Avenida 24-A, n. 1515, Bela Vista, Rio Claro, SP, 13.506-900, Brazil.,Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, SP, Brazil
| | - Rodolfo Bizarria
- Department of General and Applied Biology, São Paulo State University (UNESP), Avenida 24-A, n. 1515, Bela Vista, Rio Claro, SP, 13.506-900, Brazil.,Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, SP, Brazil
| | - Nicole Marie Gerardo
- Department of Biology, O. Wayne Rollins Research Center, Emory University, Atlanta, USA
| | - Andre Rodrigues
- Department of General and Applied Biology, São Paulo State University (UNESP), Avenida 24-A, n. 1515, Bela Vista, Rio Claro, SP, 13.506-900, Brazil. .,Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, SP, Brazil.
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Jiménez-Gómez I, Barcoto MO, Montoya QV, Goes AC, Monteiro LSVE, Bueno OC, Rodrigues A. Host Susceptibility Modulates Escovopsis Pathogenic Potential in the Fungiculture of Higher Attine Ants. Front Microbiol 2021; 12:673444. [PMID: 34194409 PMCID: PMC8238408 DOI: 10.3389/fmicb.2021.673444] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 05/14/2021] [Indexed: 12/17/2022] Open
Abstract
Health and disease emerge from intricate interactions between genotypes, phenotypes, and environmental features. The outcomes of such interactions are context-dependent, existing as a dynamic continuum ranging from benefits to damage. In host-microbial interactions, both the host and environmental conditions modulate the pathogenic potential of a microorganism. Microbial interactions are the core of the agricultural systems of ants in the subtribe Attina, which cultivate basidiomycete fungi for food. The fungiculture environment harbors a diverse microbial community, including fungi in the genus Escovopsis that has been studied as damage-causing agent. Here, we consider the ant colony as a host and investigate to what extent its health impacts the dynamics and outcomes of host-Escovopsis interactions. We found that different ant fungal cultivars vary in susceptibility to the same Escovopsis strains in plate-assays interactions. In subcolony-Escovopsis interactions, while healthy subcolonies gradually recover from infection with different concentrations of Escovopsis conidia, insecticide-treated subcolonies evidenced traits of infection and died within 7 days. The opportunistic nature of Escovopsis infections indicates that diseases in attine fungiculture are a consequence of host susceptibility, rather than the effect of a single microbial agent. By addressing the host susceptibility as a major modulator of Escovopsis pathogenesis, our findings expand the understanding of disease dynamics within attine colonies.
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Affiliation(s)
- Irina Jiménez-Gómez
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil.,Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Mariana O Barcoto
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Quimi V Montoya
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Aryel C Goes
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Lana S V E Monteiro
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Odair C Bueno
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Andre Rodrigues
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
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Christopher Y, Wcislo WT, Martínez‐Luis S, Hughes WO, Gerardo NM, Fernández‐Marín H. Disease management in two sympatric Apterostigma fungus-growing ants for controlling the parasitic fungus Escovopsis. Ecol Evol 2021; 11:6041-6052. [PMID: 34141201 PMCID: PMC8207340 DOI: 10.1002/ece3.7379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/31/2021] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
Antagonistic interactions between host and parasites are often embedded in networks of interacting species, in which hosts may be attacked by competing parasites species, and parasites may infect more than one host species. To better understand the evolution of host defenses and parasite counterdefenses in the context of a multihost, multiparasite system, we studied two sympatric species, of congeneric fungus-growing ants (Attini) species and their symbiotic fungal cultivars, which are attacked by multiple morphotypes of parasitic fungi in the genus, Escovopsis. To assess whether closely related ant species and their cultured fungi are evolving defenses against the same or different parasitic strains, we characterized Escovopsis that were isolated from colonies of sympatric Apterostigma dentigerum and A. pilosum. We assessed in vitro and in vivo interactions of these parasites with their hosts. While the ant cultivars are parasitized by similar Escovopsis spp., the frequency of infection by these pathogens differs between the two ant species. The ability of the host fungi to suppress Escovopsis growth, as well as ant defensive responses toward the parasites, differs depending on the parasite strain and on the host ant species.
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Affiliation(s)
- Yuliana Christopher
- Centro de Biodiversidad y Descubrimiento de DrogasInstituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP)ClaytonRepública de Panamá
- Department of BiotechnologyAcharya Nagarjuna UniversityGunturIndia
- Smithsonian Tropical Research InstitutePanamaRepública de Panamá
| | | | - Sergio Martínez‐Luis
- Centro de Biodiversidad y Descubrimiento de DrogasInstituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP)ClaytonRepública de Panamá
| | | | | | - Hermógenes Fernández‐Marín
- Centro de Biodiversidad y Descubrimiento de DrogasInstituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP)ClaytonRepública de Panamá
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7
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Batey SFD, Greco C, Hutchings MI, Wilkinson B. Chemical warfare between fungus-growing ants and their pathogens. Curr Opin Chem Biol 2020; 59:172-181. [PMID: 32949983 PMCID: PMC7763482 DOI: 10.1016/j.cbpa.2020.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/28/2020] [Accepted: 08/03/2020] [Indexed: 12/19/2022]
Abstract
Fungus-growing attine ants are under constant threat from fungal pathogens such as the specialized mycoparasite Escovopsis, which uses combined physical and chemical attack strategies to prey on the fungal gardens of the ants. In defence, some species assemble protective microbiomes on their exoskeletons that contain antimicrobial-producing Actinobacteria. Underlying this network of mutualistic and antagonistic interactions are an array of chemical signals. Escovopsis weberi produces the shearinine terpene-indole alkaloids, which affect ant behaviour, diketopiperazines to combat defensive bacteria, and other small molecules that inhibit the fungal cultivar. Pseudonocardia and Streptomyces mutualist bacteria produce depsipeptide and polyene macrolide antifungals active against Escovopsis spp. The ant nest metabolome is further complicated by competition between defensive bacteria, which produce antibacterials active against even closely related species. Specialist fungal pathogens attack the nests of fungus-growing ants. Ants form mutualistic relationships with defensive actinomycete bacteria. Specialised metabolites underpin these mutualistic and antagonistic interactions.
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Affiliation(s)
- Sibyl F D Batey
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, United Kingdom
| | - Claudio Greco
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, United Kingdom
| | - Matthew I Hutchings
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, United Kingdom; School of Biological Sciences, University of East Anglia, Norwich, NR4 7TU, United Kingdom.
| | - Barrie Wilkinson
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, United Kingdom.
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Bizarria R, Nagamoto NS, Rodrigues A. Lack of fungal cultivar fidelity and low virulence of Escovopsis trichodermoides. FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2020.100944] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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Caldera EJ, Chevrette MG, McDonald BR, Currie CR. Local Adaptation of Bacterial Symbionts within a Geographic Mosaic of Antibiotic Coevolution. Appl Environ Microbiol 2019; 85:e01580-19. [PMID: 31676475 PMCID: PMC6881802 DOI: 10.1128/aem.01580-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/22/2019] [Indexed: 12/19/2022] Open
Abstract
The geographic mosaic theory of coevolution (GMC) posits that coevolutionary dynamics go beyond local coevolution and are comprised of the following three components: geographic selection mosaics, coevolutionary hot spots, and trait remixing. It is unclear whether the GMC applies to bacteria, as horizontal gene transfer and cosmopolitan dispersal may violate theoretical assumptions. Here, we test key GMC predictions in an antibiotic-producing bacterial symbiont (genus Pseudonocardia) that protects the crops of neotropical fungus-farming ants (Apterostigma dentigerum) from a specialized pathogen (genus Escovopsis). We found that Pseudonocardia antibiotic inhibition of common Escovopsis pathogens was elevated in A. dentigerum colonies from Panama compared to those from Costa Rica. Furthermore, a Panama Canal Zone population of Pseudonocardia on Barro Colorado Island (BCI) was locally adapted, whereas two neighboring populations were not, consistent with a GMC-predicted selection mosaic and a hot spot of adaptation surrounded by areas of maladaptation. Maladaptation was shaped by incongruent Pseudonocardia-Escovopsis population genetic structure, whereas local adaptation was facilitated by geographic isolation on BCI after the flooding of the Panama Canal. Genomic assessments of antibiotic potential of 29 Pseudonocardia strains identified diverse and unique biosynthetic gene clusters in BCI strains despite low genetic diversity in the core genome. The strength of antibiotic inhibition was not correlated with the presence/absence of individual biosynthetic gene clusters or with parasite location. Rather, biosynthetic gene clusters have undergone selective sweeps, suggesting that the trait remixing dynamics conferring the long-term maintenance of antibiotic potency rely on evolutionary genetic changes within already-present biosynthetic gene clusters and not simply on the horizontal acquisition of novel genetic elements or pathways.IMPORTANCE Recently, coevolutionary theory in macroorganisms has been advanced by the geographic mosaic theory of coevolution (GMC), which considers how geography and local adaptation shape coevolutionary dynamics. Here, we test GMC in an ancient symbiosis in which the ant Apterostigma dentigerum cultivates fungi in an agricultural system analogous to human farming. The cultivars are parasitized by the fungus Escovopsis The ants maintain symbiotic actinobacteria with antibiotic properties that help combat Escovopsis infection. This antibiotic symbiosis has persisted for tens of millions of years, raising the question of how antibiotic potency is maintained over these time scales. Our study tests the GMC in a bacterial defensive symbiosis and in a multipartite symbiosis framework. Our results show that this multipartite symbiotic system conforms to the GMC and demonstrate that this theory is applicable in both microbes and indirect symbiont-symbiont interactions.
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Affiliation(s)
- Eric J Caldera
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Marc G Chevrette
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Bradon R McDonald
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Cameron R Currie
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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10
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Abstract
Low-cost, high-throughput nucleic acid sequencing ushered the field of microbial ecology into a new era in which the microbial composition of nearly every conceivable environment on the planet is under examination. However, static "screenshots" derived from sequence-only approaches belie the underlying complexity of the microbe-microbe and microbe-host interactions occurring within these systems. Reductionist experimental models are essential to identify the microbes involved in interactions and to characterize the molecular mechanisms that manifest as complex host and environmental phenomena. Herein, we focus on three models (Bacillus-Streptomyces, Aliivibrio fischeri-Hawaiian bobtail squid, and gnotobiotic mice) at various levels of taxonomic complexity and experimental control used to gain molecular insight into microbe-mediated interactions. We argue that when studying microbial communities, it is crucial to consider the scope of questions that experimental systems are suited to address, especially for researchers beginning new projects. Therefore, we highlight practical applications, limitations, and tradeoffs inherent to each model.
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Affiliation(s)
- Marc G Chevrette
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jennifer R Bratburd
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Cameron R Currie
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Reed M Stubbendieck
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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11
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Escovopsis kreiselii specialization to its native hosts in the fungiculture of the lower attine ant Mycetophylax morschi. Antonie van Leeuwenhoek 2018; 112:305-317. [PMID: 30206787 DOI: 10.1007/s10482-018-1158-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/29/2018] [Indexed: 10/28/2022]
Abstract
Parasite-host associations are widespread in nature and the fungus-growing ants are considered model organisms to study such interactions. These insects cultivate basidiomycetous fungi for food, which are threatened by mycotrophic fungi in the genus Escovopsis. Although recently described from colonies of the lower attine ant Mycetophylax morschi, the biology and pathogenicity of Escovopsis kreiselii are unknown. Herein, we evaluated the interaction of E. kreiselii with fungi cultivated by M. morschi (native hosts) and with a fungus cultivated by another attine ant species (non-native host). In addition, we examined the physical interactions between hypha of E. kreiselii and hypha from its native hosts using scanning electron microscopy. Escovopsis kreiselii inhibited the growth of fungal cultivars by 24% or more (with exception of one isolate), when compared to the fungal cultivars growing alone. Escovopsis kreiselii is attracted towards its native hosts through chemotaxis and inhibition occurs when there is physical contact with the hyphae of the fungal cultivar. As reported for Escovopsis parasites associated with leafcutter ants (higher attines), E. kreiselii growth increased in the presence of its native hosts, even before contact between both fungi occurred. In interactions with the fungal cultivar that is not naturally infected by E. kreiselii (non-native host), it caused inhibition but not at the same magnitude as in native hosts. Multiple lines of evidence suggest that E. kreiselii is an antagonist of the fungus cultivated by M. morschi and can chemically recognize such fungus.
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Kellner K, Kardish MR, Seal JN, Linksvayer TA, Mueller UG. Symbiont-Mediated Host-Parasite Dynamics in a Fungus-Gardening Ant. MICROBIAL ECOLOGY 2018; 76:530-543. [PMID: 29285550 DOI: 10.1007/s00248-017-1124-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 12/01/2017] [Indexed: 06/07/2023]
Abstract
Group-living can promote the evolution of adaptive strategies to prevent and control disease. Fungus-gardening ants must cope with two sets of pathogens, those that afflict the ants themselves and those of their symbiotic fungal gardens. While much research has demonstrated the impact of specialized fungal pathogens that infect ant fungus gardens, most of these studies focused on the so-called higher attine ants, which are thought to coevolve diffusely with two clades of leucocoprinaceous fungi. Relatively few studies have addressed disease ecology of lower Attini, which are thought to occasionally recruit (domesticate) novel leucocoprinaceous fungi from free-living populations; coevolution between lower-attine ants and their fungi is therefore likely weaker (or even absent) than in the higher Attini, which generally have many derived modifications. Toward understanding the disease ecology of lower-attine ants, this study (a) describes the diversity in the microfungal genus Escovopsis that naturally infect fungus gardens of the lower-attine ant Mycocepurus smithii and (b) experimentally determines the relative contributions of Escovopsis strain (a possible garden disease), M. smithii ant genotype, and fungal cultivar lineage to disease susceptibility and colony fitness. In controlled in-vivo infection laboratory experiments, we demonstrate that the susceptibility to Escovopsis infection was an outcome of ant-cultivar-Escovopsis interaction, rather than solely due to ant genotype or fungal cultivar lineage. The role of complex ant-cultivar-Escovopsis interactions suggests that switching M. smithii farmers onto novel fungus types might be a strategy to generate novel ant-fungus combinations resistant to most, but perhaps not all, Escovopsis strains circulating in a local population of this and other lower-attine ants.
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Affiliation(s)
- Katrin Kellner
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA.
- Department of Biology, University of Texas at Tyler, Tyler, TX, 75799, USA.
| | - M R Kardish
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
- Deptartment of Evolution and Ecology, University of California, Davis, CA, 95616, USA
| | - J N Seal
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
- Department of Biology, University of Texas at Tyler, Tyler, TX, 75799, USA
| | - T A Linksvayer
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - U G Mueller
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
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Green PWC, Kooij PW. The role of chemical signalling in maintenance of the fungus garden by leaf-cutting ants. CHEMOECOLOGY 2018. [DOI: 10.1007/s00049-018-0260-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Mueller UG, Kardish MR, Ishak HD, Wright AM, Solomon SE, Bruschi SM, Carlson AL, Bacci M. Phylogenetic patterns of ant-fungus associations indicate that farming strategies, not only a superior fungal cultivar, explain the ecological success of leafcutter ants. Mol Ecol 2018; 27:2414-2434. [PMID: 29740906 DOI: 10.1111/mec.14588] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 01/18/2023]
Abstract
To elucidate fungicultural specializations contributing to ecological dominance of leafcutter ants, we estimate the phylogeny of fungi cultivated by fungus-growing (attine) ants, including fungal cultivars from (i) the entire leafcutter range from southern South America to southern North America, (ii) all higher-attine ant lineages (leafcutting genera Atta, Acromyrmex; nonleafcutting genera Trachymyrmex, Sericomyrmex) and (iii) all lower-attine lineages. Higher-attine fungi form two clades, Clade-A fungi (Leucocoprinus gongylophorus, formerly Attamyces) previously thought to be cultivated only by leafcutter ants, and a sister clade, Clade-B fungi, previously thought to be cultivated only by Trachymyrmex and Sericomyrmex ants. Contradicting this traditional view, we find that (i) leafcutter ants are not specialized to cultivate only Clade-A fungi because some leafcutter species ranging across South America cultivate Clade-B fungi; (ii) Trachymyrmex ants are not specialized to cultivate only Clade-B fungi because some Trachymyrmex species cultivate Clade-A fungi and other Trachymyrmex species cultivate fungi known so far only from lower-attine ants; (iii) in some locations, single higher-attine ant species or closely related cryptic species cultivate both Clade-A and Clade-B fungi; and (iv) ant-fungus co-evolution among higher-attine mutualisms is therefore less specialized than previously thought. Sympatric leafcutter ants can be ecologically dominant when cultivating either Clade-A or Clade-B fungi, sustaining with either cultivar-type huge nests that command large foraging territories; conversely, sympatric Trachymyrmex ants cultivating either Clade-A or Clade-B fungi can be locally abundant without achieving the ecological dominance of leafcutter ants. Ecological dominance of leafcutter ants therefore does not depend primarily on specialized fungiculture of L. gongylophorus (Clade-A), but must derive from ant-fungus synergisms and unique ant adaptations.
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Affiliation(s)
- Ulrich G Mueller
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas
| | - Melissa R Kardish
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas.,Center for Population Biology, University of California, Davis, California
| | - Heather D Ishak
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas.,Department of Medicine, Stanford University, Stanford, California
| | - April M Wright
- Department of Biological Science, Southeastern Louisiana University, Hammond, Louisiana
| | - Scott E Solomon
- Department of Ecology and Evolutionary Biology, Rice University, Houston, Texas.,Department of Entomology, Smithsonian Institution, Washington, District of Columbia
| | - Sofia M Bruschi
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas.,Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | - Alexis L Carlson
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas
| | - Maurício Bacci
- Centro de Estudos de Insetos Sociais, Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
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15
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Varanda-Haifig SS, Albarici TR, Nunes PH, Haifig I, Vieira PC, Rodrigues A. Nature of the interactions between hypocrealean fungi and the mutualistic fungus of leaf-cutter ants. Antonie van Leeuwenhoek 2016; 110:593-605. [PMID: 28040855 DOI: 10.1007/s10482-016-0826-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 12/22/2016] [Indexed: 11/25/2022]
Abstract
Leaf-cutter ants cultivate and feed on the mutualistic fungus, Leucoagaricus gongylophorus, which is threatened by parasitic fungi of the genus Escovopsis. The mechanism of Escovopsis parasitism is poorly understood. Here, we assessed the nature of the antagonism of different Escovopsis species against its host. We also evaluated the potential antagonism of Escovopsioides, a recently described fungal genus from the attine ant environment whose role in the colonies of these insects is unknown. We performed dual-culture assays to assess the interactions between L. gongylophorus and both fungi. We also evaluated the antifungal activity of compounds secreted by the latter on L. gongylophorus growth using crude extracts of Escovopsis spp. and Escovopsioides nivea obtained either in (1) absence or (2) presence of the mutualistic fungus. The physical interaction between these fungi and the mutualistic fungus was examined under scanning electron microscopy (SEM). Escovopsis spp. and E. nivea negatively affected the growth of L. gongylophorus, which was also significantly inhibited by both types of crude extract. These results indicate that Escovopsis spp. and E. nivea produce antifungal metabolites against the mutualistic fungus. SEM showed that Escovopsis spp. and E. nivea maintained physical contact with the mutualistic fungus, though no specialised structures related to mycoparasitism were observed. These results showed that Escovopsis is a destructive mycoparasite that needs physical contact for the death of the mutualistic fungus to occur. Also, our findings suggest that E. nivea is an antagonist of the ant fungal cultivar.
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Affiliation(s)
- Sadala Schmidt Varanda-Haifig
- Departamento de Bioquímica e Microbiologia, Universidade Estadual Paulista (UNESP), Av. 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil
| | - Tatiane Regina Albarici
- Departamento de Química, Universidade Federal de São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP, 13565-905, Brazil
| | - Pablo Henrique Nunes
- Centro Interdisciplinar de Ciências da Vida, Universidade Federal da Integração Latino-Americana, Av. Tancredo Neves, 6731 - Bloco 6, Caixa Postal 2044, Foz do Iguaçu, PR, 85867-970, Brazil
| | - Ives Haifig
- Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Campus Monte Carmelo. Rodovia LMG-746, km 1, Monte Carmelo, MG, 38500-000, Brazil
| | - Paulo Cezar Vieira
- Departamento de Química, Universidade Federal de São Carlos, Rodovia Washington Luís, km 235, São Carlos, SP, 13565-905, Brazil
| | - Andre Rodrigues
- Departamento de Bioquímica e Microbiologia, Universidade Estadual Paulista (UNESP), Av. 24A, 1515, Bela Vista, Rio Claro, SP, 13506-900, Brazil.
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16
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de Man TJB, Stajich JE, Kubicek CP, Teiling C, Chenthamara K, Atanasova L, Druzhinina IS, Levenkova N, Birnbaum SSL, Barribeau SM, Bozick BA, Suen G, Currie CR, Gerardo NM. Small genome of the fungus Escovopsis weberi, a specialized disease agent of ant agriculture. Proc Natl Acad Sci U S A 2016; 113:3567-72. [PMID: 26976598 PMCID: PMC4822581 DOI: 10.1073/pnas.1518501113] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many microorganisms with specialized lifestyles have reduced genomes. This is best understood in beneficial bacterial symbioses, where partner fidelity facilitates loss of genes necessary for living independently. Specialized microbial pathogens may also exhibit gene loss relative to generalists. Here, we demonstrate that Escovopsis weberi, a fungal parasite of the crops of fungus-growing ants, has a reduced genome in terms of both size and gene content relative to closely related but less specialized fungi. Although primary metabolism genes have been retained, the E. weberi genome is depleted in carbohydrate active enzymes, which is consistent with reliance on a host with these functions. E. weberi has also lost genes considered necessary for sexual reproduction. Contrasting these losses, the genome encodes unique secondary metabolite biosynthesis clusters, some of which include genes that exhibit up-regulated expression during host attack. Thus, the specialized nature of the interaction between Escovopsis and ant agriculture is reflected in the parasite's genome.
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Affiliation(s)
- Tom J B de Man
- Department of Biology, Emory University, Atlanta, GA 30322
| | - Jason E Stajich
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521
| | - Christian P Kubicek
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | | | - Komal Chenthamara
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | - Lea Atanasova
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | - Irina S Druzhinina
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | | | | | - Seth M Barribeau
- Department of Biology, Emory University, Atlanta, GA 30322; Department of Biology, East Carolina University, Greenville, NC 27858
| | | | - Garret Suen
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706
| | - Cameron R Currie
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706
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