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Samples RM, Balunas MJ. Bridging the Gap: Plant-Endophyte Interactions as a Roadmap to Understanding Small-Molecule Communication in Marine Microbiomes. Chembiochem 2020; 21:2708-2721. [PMID: 32324967 DOI: 10.1002/cbic.202000064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/20/2020] [Indexed: 12/16/2022]
Abstract
Probing the composition of the microbiome and its association with health and disease states is more accessible than ever due to the rise of affordable sequencing technology. Despite advances in our ability to identify members of symbiont communities, untangling the chemical signaling that they use to communicate with host organisms remains challenging. In order to gain a greater mechanistic understanding of how the microbiome impacts health, and how chemical ecology can be leveraged to advance small-molecule drug discovery from microorganisms, the principals governing communication between host and symbiont must be elucidated. Herein, we review common modes of interkingdom small-molecule communication in terrestrial and marine environments, describe the differences between these environments, and detail the advantages and disadvantages for studies focused on the marine environment. Finally, we propose the use of plant-endophyte interactions as a stepping stone to a greater understanding of similar interactions in marine invertebrates, and ultimately in humans.
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Affiliation(s)
- Robert M Samples
- Division of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, 06269, USA.,Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Marcy J Balunas
- Division of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT, 06269, USA
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2
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Cabral D, Cafaro MJ, Saidman B, Lugo M, Reddy PV, White JF. Evidence supporting the occurrence of a new species of endophyte in some South American grasses. Mycologia 2019. [DOI: 10.1080/00275514.1999.12061021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Daniel Cabral
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | - Matías J. Cafaro
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | - B. Saidman
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | - M. Lugo
- Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | - Ponaka V. Reddy
- Department of Plant Pathology, Cook College-Rutgers University, New Brunswick, New Jersey, 80901
| | - James F. White
- Department of Plant Pathology, Cook College-Rutgers University, New Brunswick, New Jersey, 80901
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3
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Sullivan RF, Bills GF, Hywel-Jones NL, White JF. Hyperdermium: a new clavicipitalean genus for some tropical epibionts of dicotyledonous plants. Mycologia 2019. [DOI: 10.1080/00275514.2000.12061236] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Raymond F. Sullivan
- Department of Plant Pathology, Cook College-Rutgers University, New Brunswick, New Jersey 08901
| | - Gerald F. Bills
- Merck Research Laboratories, Natural Products Drug Discovery, P.O. Box 2000, Rahway, New Jersey 07065
| | - Nigel L. Hywel-Jones
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science, Technology and Environmental Building Rama VI Road, Bangkok 10400, Thailand
| | - James F. White
- Department of Plant Pathology, Cook College-Rutgers University, New Brunswick, New Jersey 08901
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4
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Leuchtmann A, Schardl CL, Siegel MR. Sexual compatibility and taxonomy of a new species of Epichloë symbiotic with fine fescue grasses. Mycologia 2018. [DOI: 10.1080/00275514.1994.12026487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Adrian Leuchtmann
- Geobotanisches Institut ETH, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | | | - Malcolm R. Siegel
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546
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5
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Bacon CW, Yates IE, Hinton DM, Meredith F. Biological control of Fusarium moniliforme in maize. ENVIRONMENTAL HEALTH PERSPECTIVES 2001; 109 Suppl 2:325-32. [PMID: 11359703 PMCID: PMC1240683 DOI: 10.1289/ehp.01109s2325] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Fusarium moniliforme Sheldon, a biological species of the mating populations within the (italic)Gibberella fujikuroi species complex, i.e., population A [= G. moniliformis (Sheld.) Wineland], is an example of a facultative fungal endophyte. During the biotrophic endophytic association with maize, as well as during saprophytic growth, F. moniliforme produces the fumonisins. The fungus is transmitted vertically and horizontally to the next generation of plants via clonal infection of seeds and plant debris. Horizontal infection is the manner by which this fungus is spread contagiously and through which infection occurs from the outside that can be reduced by application of certain fungicides. The endophytic phase is vertically transmitted. This type infection is important because it is not controlled by seed applications of fungicides, and it remains the reservoir from which infection and toxin biosynthesis takes place in each generation of plants. Thus, vertical transmission of this fungus is just as important as horizontal transmission. A biological control system using an endophytic bacterium, Bacillus subtilis, has been developed that shows great promise for reducing mycotoxin accumulation during the endophytic (vertical transmission) growth phase. Because this bacterium occupies the identical ecological niche within the plant, it is considered an ecological homologue to F. moniliforme, and the inhibitory mechanism, regardless of the mode of action, operates on the competitive exclusion principle. In addition to this bacterium, an isolate of a species of the fungus Trichoderma shows promise in the postharvest control of the growth and toxin accumulation from F. moniliforme on corn in storage.
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Affiliation(s)
- C W Bacon
- U.S. Department of Agriculture, Agricultural Research Service, Toxicology and Mycotoxin Research Unit, Russell Research Center, Athens, Georgia, USA.
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6
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Sánchez MS, Arnold J, Asmussen MA. Symbiont survival and host-symbiont disequilibria under differential vertical transmission. Genetics 2000; 154:1347-65. [PMID: 10757775 PMCID: PMC1460980 DOI: 10.1093/genetics/154.3.1347] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Interspecific genetic interactions in host-symbiont systems raise intriguing coevolutionary questions and may influence the effectiveness of public health and management policies. Here we present an analytical and numerical investigation of the effects of host genetic heterogeneity in the rate of vertical transmission of a symbiont. We consider the baseline case with a monomorphic symbiont and a single diallelic locus in its diploid host, where vertical transmission is the sole force. Our analysis introduces interspecific disequilibria to quantify nonrandom associations between host genotypes and alleles and symbiont presence/absence. The transient and equilibrium behavior is examined in simulations with randomly generated initial conditions and transmission parameters. Compared to the case where vertical transmission rates are uniform across host genotypes, differential transmission (i) increases average symbiont survival from 50% to almost 60%, (ii) dramatically reduces the minimum average transmission rate for symbiont survival from 0.5 to 0.008, and (iii) readily creates permanent host-symbiont disequilibria de novo, whereas uniform transmission can neither create nor maintain such associations. On average, heterozygotes are slightly more likely to carry and maintain the symbiont in the population and are more randomly associated with the symbiont. Results show that simple evolutionary forces can create substantial nonrandom associations between two species.
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Affiliation(s)
- M S Sánchez
- Department of Genetics, University of Georgia, Athens, Georgia 30602, USA.
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7
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Kuldau GA, Tsai HF, Schardl CL. Genome sizes of Epichloëspecies and anamorphic hybrids. Mycologia 1999. [DOI: 10.1080/00275514.1999.12061083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Gretchen A. Kuldau
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546-0091, USA
| | - Huei-Fung Tsai
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546-0091, USA
| | - Christopher L. Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546-0091, USA
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8
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Chung KR, Schardl CL. Vegetative compatibility between and within Epichloëspecies. Mycologia 1997. [DOI: 10.1080/00275514.1997.12026819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Kuang-Ren Chung
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546-0091
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10
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Schardl CL. EPICHLOE SPECIES: fungal symbionts of grasses. ANNUAL REVIEW OF PHYTOPATHOLOGY 1996; 34:109-30. [PMID: 15012537 DOI: 10.1146/annurev.phyto.34.1.109] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Epichloë species and their asexual descendants (Acremonium endophytes) are fungal symbionts of C3 grasses that span the symbiotic continuum from antagonism to mutualism depending on the relative importance, respectively, of horizontal transmission of sexual spores versus vertical clonal transmission in healthy grass seeds. At least seven sexual Epichloë species are identifiable by mating tests, and many asexual genotypes are interspecific hybrids. Benefits conferred by the symbionts on host plants include protection from biotic factors and abiotic stresses such as drought. Four classes of beneficial alkaloids are associated with the symbionts: ergot alkaloids, indolediterpenes (lolitrems), peramine, and saturated aminopyrrolizidines (lolines). These alkaloids protect host plants from insect and vertebrate herbivores, including livestock. Genetic engineering of the fungal symbionts as more suitable biological protectants for forage grasses requires identification of fungal genes for alkaloid biosynthesis, and DNA-mediated transformation of the fungi.
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Affiliation(s)
- C L Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky 40546-0091, USA
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11
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Jackson JA, Varney DR, Petroski RJ, Powell RG, Bush LP, Siegel MR, Hemken RW, Zavos PM. Physiological responses of rats fed loline and ergot alkaloids from endophyte-infected tall fescue. Drug Chem Toxicol 1996; 19:85-96. [PMID: 8804555 DOI: 10.3109/01480549609002198] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sixty-three male sprague Dawley rats were randomly assigned to dietary treatments containing 1) N-formylloline alkaloid (NFL), 2) N-acetylloline alkaloid (NAL), 3) NFL + NAL, 4) NFL + a mixture of ergot alkaloids, 5) NAL + a mixture of ergot alkaloids, 6) NFL + NAL + a mixture of ergot alkaloids, 7) a mixture of ergot alkaloids, 8) endophyte-free tall fescue seed (EFTF), and 9) endophyte-infected tall fescue (EITF) seed (negative control). All diets were prepared by mixing the prepared treatments and Laboratory Chow (1:1 ratio) and were fed at a maximum of 15 g per rat per day. All rats were killed at termination (d 18). Rats fed the EITF consumed less (P < .05) than those fed all other treatments. Feed intake for rats fed the NFL + ergot alkaloids was lower than for those fed NAL, NAL + ergot alkaloids, NFL + NAL + ergot alkaloids, ergot alkaloids, and EFTF treatments. Average daily weight gains (ADG) followed a trend similar to feed intake with some exceptions. Rats fed the NFL + NAL treatments had higher (P < .05) ADG than those fed all other treatments except the NFL + NAL + ergot alkaloid treatment. Rats fed the EITF had lower (P < .05) ADG than those fed all other treatments except those fed ergot alkaloids and NAL + ergot alkaloids. Epididymides, testes, hypothalamus, corpus striatum weights, prolactin and alkaline phosphatase content were not altered by dietary treatments. Results suggest that loline alkaloids may have a slight depressing effect on feed intake.
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Affiliation(s)
- J A Jackson
- Department of Animal Sciences, University of Kentucky, Lexington 40546-0215, USA
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12
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Collett MA, Bradshaw RE, Scott DB. A mutualistic fungal symbiont of perennial ryegrass contains two different pyr4 genes, both expressing orotidine-5'-monophosphate decarboxylase. Gene 1995; 158:31-9. [PMID: 7789808 DOI: 10.1016/0378-1119(95)00143-t] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A fragment of the Claviceps purpurea pyr4 gene, encoding orotidine-5'-monophosphate decarboxylase (OMP decarboxylase), was used to screen a genomic library from an isolate of a fungus, Acremonium sp. (designated Lp1), which grows as an endophyte in perennial ryegrass (Lolium perenne). Three positive clones, lambda MC11, lambda MC12 and lambda MC14, were isolated. Two of these clones, lambda MC12 and lambda MC14, were overlapping clones from the same locus, while lambda MC11 was from a different locus. Fragments of these clones which hybridised with C. purpurea pyr4 were sequenced and found to have similarity with pyr4 from other Pyrenomycete fungi. The pyr4 gene from lambda MC12 and lambda MC14 was designated pyr4-1 and that from lambda MC11 was designated pyr4-2. The predicted ORFs of the two genes were highly conserved, with 97.5% identity at the nucleotide level, the 5' non-coding sequences were the least conserved with 88.5% identity and the 3' non-coding sequences had 93.0% identity. RT-PCR analysis of total RNA from Lp1 demonstrated that transcripts from the two genes were present at similar levels, and hybridisation of pyr4-1 to Northern blots of total RNA from Lp1 showed that full-length transcripts were being produced. Genomic fragments containing pyr4 were transformed into a strain of Aspergillus nidulans which has a mutation in pyrG (encoding OMP decarboxylase). Both pyr4-1 and pyr4-2 complemented the pyrG mutation in A. nidulans, indicating that both encode functional OMP decarboxylases. It has been proposed [Schardl et al., Genetics 136 (1994) 1307-1317] that the two pyr4 in Lp1 arose by interspecific hybridisation, most likely between the ryegrass choke pathogen, Epichloë typhina, and another endophyte from perennial ryegrass, Acremonium lolii. Analysis by PCR amplification and direct sequencing of the variable 5' non-coding regions of pyr4, from possible ancestors to Lp1 supports this hypothesis. Comparisons of these sequences to the 5' non-coding sequences from pyr4-1 and pyr4-2 demonstrated that E. typhina and A. lolii were the most likely ancestors of the two pyr4 found in Lp1.
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Affiliation(s)
- M A Collett
- Department of Microbiology and Genetics, Massey University, Palmerston North, New Zealand
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Tsai HF, Liu JS, Staben C, Christensen MJ, Latch GC, Siegel MR, Schardl CL. Evolutionary diversification of fungal endophytes of tall fescue grass by hybridization with Epichloë species. Proc Natl Acad Sci U S A 1994; 91:2542-6. [PMID: 8172623 PMCID: PMC43405 DOI: 10.1073/pnas.91.7.2542] [Citation(s) in RCA: 199] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The mutualistic associations of tall fescue (Festuca arundinacea) with seed-borne fungal symbionts (endophytes) are important for fitness of the grass host and its survival under biotic and abiotic stress. The tall fescue endophytes are asexual relatives of biological species (mating populations) of genus Epichloë (Clavicipitaceae), sexual fungi that cause grass choke disease. Isozyme studies have suggested considerable genetic diversity among endophytes of tall fescue. Phylogenetic relationships among seven isolates from tall fescue, three from meadow fescue (a probable ancestor of tall fescue), and nine Epichloë isolates from other host species were investigated by comparing sequences of noncoding segments of the beta-tubulin (tub2) and rRNA (rrn) genes. Whereas each Epichloë isolate and meadow fescue endophyte had only a single tub2 gene, most tall fescue endophytes had two or three distinct tub2 copies. Phylogenetic analysis of tub2 sequences indicated that the presence of multiple copies in the tall fescue endophytes was a consequence of hybridization with Epichloë species. At least three hybridization events account for the distribution and relationships of tub2 genes. These results suggest that interspecific hybridization is the major cause of genetic diversification of the tall fescue endophytes.
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Affiliation(s)
- H F Tsai
- Department of Plant Pathology, University of Kentucky, Lexington 40546-0091
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Leuchtmann A. Isozyme relationships of Acremonium endophytes from twelve Festuca species. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/s0953-7562(09)80331-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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An ZQ, Siegel MR, Hollin W, Tsai HF, Schmidt D, Schardl CL. Relationships among non-Acremonium sp. fungal endophytes in five grass species. Appl Environ Microbiol 1993; 59:1540-8. [PMID: 8517749 PMCID: PMC182116 DOI: 10.1128/aem.59.5.1540-1548.1993] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Many cool-season grasses (subfamily Pooideae) possess maternally transmitted fungal symbionts which cause no known pathology and often enhance the ecological fitness and biochemical capabilities of the grass hosts. The most commonly described endophytes are the Acremonium section Albo-lanosa spp. (Acremonium endophytes), which are conidial anamorphs (strictly asexual forms) of Epichloë typhina. Other endophytes which have been noted are a Gliocladium-like fungus in perennial ryegrass (Lolium perenne L.) and a Phialophora-like fungus in tall fescue (Festuca arundinacea Schreb.). Here, we report the identification of additional non-Acremonium sp. endophytes (herein designated p-endophytes) in three more grass species: Festuca gigantea, Festuca arizonica, and Festuca pratensis. In each grass species, the p-endophyte was cosymbiotic with an Acremonium endophyte. Serological analysis and sequence determinations of variable portions of their rRNA genes indicated that the two previously identified non-Acremonium endophytes are closely related to each other and to the newly identified p-endophytes. Therefore, the p-endophytes represent a second group of widely distributed grass symbionts.
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Affiliation(s)
- Z Q An
- Department of Plant Pathology, University of Kentucky, Lexington 40546-0091
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Schardl CL, An Z. Molecular biology and genetics of protective fungal endophytes of grasses. GENETIC ENGINEERING 1993; 15:191-212. [PMID: 7763840 DOI: 10.1007/978-1-4899-1666-2_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- C L Schardl
- Department of Plant Pathology, University of Kentucky, Lexington 40546-0091
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