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Wong S, Kaur J, Kumar P, Karremans AP, Sharma J. Distinct orchid mycorrhizal fungal communities among co-occurring Vanilla species in Costa Rica: root substrate and population-based segregation. MYCORRHIZA 2024; 34:229-250. [PMID: 38664239 DOI: 10.1007/s00572-024-01147-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/15/2024] [Indexed: 06/12/2024]
Abstract
Despite being the second largest family of flowering plants, orchids represent community structure variation in plant-microbial associations, contributes to niche partitioning in metacommunity assemblages. Yet, mycorrhizal communities and interactions remain unknown for orchids that are highly specialized or even obligated in their associations with their mycorrhizal partners. In this study, we sought to compare orchid mycorrhizal fungal (OMF) communities of three co-occurring hemiepiphytic Vanilla species (V. hartii, V. pompona, and V. trigonocarpa) in tropical forests of Costa Rica by addressing the identity of their OMF communities across species, root types, and populations, using high-throughput sequencing. Sequencing the nuclear ribosomal internal transcribed spacer (nrITS) yielded 299 fungal Operational Taxonomic Units (OTUs) from 193 root samples. We showed distinct segregation in the putative OMF (pOMF) communities of the three coexisting Vanilla hosts. We also found that mycorrhizal communities associated with the rare V. hartii varied among populations. Furthermore, we identified Tulasnellaceae and Ceratobasidiaceae as dominant pOMF families in terrestrial roots of the three Vanilla species. In contrast, the epiphytic roots were mainly dominated by OTUs belonging to the Atractiellales and Serendipitaceae. Furthermore, the pOMF communities differed significantly across populations of the widespread V. trigonocarpa and showed patterns of distance decay in similarity. This is the first report of different pOMF communities detected in roots of wild co-occurring Vanilla species using high-throughput sequencing, which provides evidence that three coexisting Vanilla species and their root types exhibited pOMF niche partitioning, and that the rare and widespread Vanilla hosts displayed diverse mycorrhizal preferences.
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Affiliation(s)
- Shan Wong
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA.
| | - Jaspreet Kaur
- Department of Biology, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, WI, 54601, USA
| | - Pankaj Kumar
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA
| | - Adam P Karremans
- Lankester Botanical Garden, University of Costa Rica, P.O. Box 302-7050, Cartago, Costa Rica
| | - Jyotsna Sharma
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA
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Wang D, Trimbos KB, Gomes SIF, Jacquemyn H, Merckx VSFT. Metabarcoding read abundances of orchid mycorrhizal fungi are correlated to copy numbers estimated using ddPCR. THE NEW PHYTOLOGIST 2024; 242:1825-1834. [PMID: 37929750 DOI: 10.1111/nph.19385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/20/2023] [Indexed: 11/07/2023]
Abstract
Quantifying the abundances of fungi is key to understanding natural variation in mycorrhizal communities in relation to plant ecophysiology and environmental heterogeneity. High-throughput metabarcoding approaches have transformed our ability to characterize and compare complex mycorrhizal communities. However, it remains unclear how well metabarcoding read counts correlate with actual read abundances in the sample, potentially limiting their use as a proxy for species abundances. Here, we use droplet digital PCR (ddPCR) to evaluate the reliability of ITS2 metabarcoding data for quantitative assessments of mycorrhizal communities in the orchid species Neottia ovata sampled at multiple sites. We performed specific ddPCR assays for eight families of orchid mycorrhizal fungi and compared the results with read counts obtained from metabarcoding. Our results demonstrate a significant correlation between DNA copy numbers measured by ddPCR assays and metabarcoding read counts of major mycorrhizal partners of N. ovata, highlighting the usefulness of metabarcoding for quantifying the abundance of orchid mycorrhizal fungi. Yet, the levels of correlation between the two methods and the numbers of false zero values varied across fungal families, which warrants cautious evaluation of the reliability of low-abundance families. This study underscores the potential of metabarcoding data for more quantitative analyses of mycorrhizal communities and presents practical workflows for metabarcoding and ddPCR to achieve a more comprehensive understanding of orchid mycorrhizal communities.
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Affiliation(s)
- Deyi Wang
- Naturalis Biodiversity Center, 2332 AA, Leiden, the Netherlands
- Institute of Biology, Leiden University, 2333 BE, Leiden, the Netherlands
| | - Krijn B Trimbos
- Department of Environmental Biology, Institute of Environmental Sciences, 2333 CC, Leiden University, Leiden, the Netherlands
| | - Sofia I F Gomes
- Institute of Biology, Leiden University, 2333 BE, Leiden, the Netherlands
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Kasteelpark Arenberg 31, Heverlee, 3001, Leuven, Belgium
| | - Vincent S F T Merckx
- Naturalis Biodiversity Center, 2332 AA, Leiden, the Netherlands
- Department of Evolutionary and Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, 1098 XH, Amsterdam, the Netherlands
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Calevo J, Duffy KJ. Interactions among mycorrhizal fungi enhance the early development of a Mediterranean orchid. MYCORRHIZA 2023; 33:229-240. [PMID: 37436449 PMCID: PMC10442268 DOI: 10.1007/s00572-023-01118-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 06/20/2023] [Indexed: 07/13/2023]
Abstract
Orchids depend on mycorrhizal fungi to germinate from seed. While multiple orchid mycorrhizal (OrM) taxa are often found associated with adult orchids, the relative contribution of particular OrM taxa to germination and early orchid development is poorly understood. We isolated 28 OrM fungi associated with the Mediterranean orchid Anacamptis papilionacea and tested the efficiency of five isolates on germination and early development, four belonging to the Tulasnella calospora species complex and one belonging to Ceratobasidium. Co-cultures of varying two-way and three-way combinations of OrM isolates were used in vitro to compare the simultaneous effect on seed germination rate with monocultures. We then tested whether, when given initial priority over other fungi, particular OrM taxa were more effective during the early stages of development. Seedlings germinated with different isolates were transferred to a growth chamber, and either the same or different isolate was added 45 days later. After 3 months, the number of roots, length of the longest root, and tuber area were measured. All OrM fungi resulted in seed germination; however, lower germination rates were associated with the Ceratobasidium isolate compared to the tulasnelloid isolates. There was significant decreased germination in co-culture experiments when the Ceratobasidium isolate was added. Despite being associated with reduced germination rates, the addition of the Ceratobasidium isolate to the seedlings germinated with tulasnelloid strains resulted in significant increased tuber size. Although A. papilionacea associates with many OrM taxa, these results show that OrM fungi may play different roles during orchid germination and early development. Even when given initial priority, other fungi may colonize developing orchids and interact to influence early orchid development.
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Affiliation(s)
- Jacopo Calevo
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia, 80126, Naples, Italy.
| | - Karl J Duffy
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia, 80126, Naples, Italy.
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Yao N, Zheng B, Wang T, Cao X. Isolation of Tulasnella spp. from Cultivated Paphiopedilum Orchids and Screening of Germination-Enhancing Fungi. J Fungi (Basel) 2023; 9:597. [PMID: 37367533 DOI: 10.3390/jof9060597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/18/2023] [Accepted: 05/18/2023] [Indexed: 06/28/2023] Open
Abstract
Ex situ conservation, an important way to increase the survival and sustainability of endangered species, is widely used in the conservation of endangered orchids. However, long-term ex situ conservation might affect the dominant group of orchid symbiotic fungi, which are crucial for orchid growth and reintroduction. This study investigated the culturable Tulasnella spp. associated with Paphiopedilum orchids after long-term greenhouse cultivation, and identified germination-enhancing isolates. A total of 44 Tulasnella isolates were obtained from the roots of 14 Paphiopedilum spp., and 29 of them were selected for phylogenetic analysis. They clustered mainly with Tulasnella deliquescens, Tulasnella calospora, Tulasnella bifrons, and Tulasnella irregularis, but included two potential new groups. Compared with published uncultured data, most of the isolates were grouped together with the reported types, and the dominant Tulasnella associated with P. armeniacum and P. micranthum could still be isolated after ten years of cultivation, most of which were the first isolation. In vitro symbiotic germination showed that certain root isolates could promote seed germination (e.g., parm152 isolated from P. armeniacum, Php12 from P. hirsutissimum, and prhi68 from P. rhizomatosum). These data indicated that the dominant Tulasnella types colonizing the roots of cultivated Paphiopedilum are stable over time, and germination-enhancing fungi colonizing the roots would benefit for seed reproduction after population reintroduction into the wild.
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Affiliation(s)
- Na Yao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Baoqiang Zheng
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Tao Wang
- Beijing Laboratory of Urban and Rural Ecological Environment, Beijing Floriculture Engineering Technology Research Centre, China National Botanical Garden (North Garden), Beijing 100093, China
| | - Xiaolu Cao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
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Perez‐Lamarque B, Laurent‐Webb L, Bourceret A, Maillet L, Bik F, Cartier D, Labolle F, Holveck P, Epp D, Selosse M. Fungal microbiomes associated with Lycopodiaceae during ecological succession. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:109-118. [PMID: 36216403 PMCID: PMC10103886 DOI: 10.1111/1758-2229.13130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/27/2022] [Indexed: 05/20/2023]
Abstract
Lycopodiaceae species form an early-diverging plant family, characterized by achlorophyllous and subterranean gametophytes that rely on mycorrhizal fungi for their nutrition. Lycopodiaceae often emerge after a disturbance, like in the Hochfeld reserve (Alsace, France) where seven lycopod species appeared on new ski trails following a forest cut. Here, to better understand their ecological dynamic, we conducted a germination experiment of lycopod spores following an anthropogenic disturbance and examined their associated fungi. Only 12% of the samples germinated, and all gametophytes were abundantly colonized by a specific clade of Densosporaceae (Endogonales, Mucoromycotina), which were also present in the roots of lycopod sporophytes, but absent from the ungerminated spores and the roots of surrounding herbaceous plants, suggesting high mycorrhizal specificity in Lycopodiaceae. In addition, ungerminated spores were profusely parasitized by chytrid fungi, also present in the surrounding lycopod gametophytes and sporophytes, which might explain the low spore germination rate. Altogether, the requirement of specific mycorrhizal Mucoromycotina fungi and the high prevalence of parasites may explain why Lycopodiaceae are often rare pioneer species in temperate regions, limited to the first stages of ecological succession. This illustrates the primordial roles that belowground microbes play in aboveground plant dynamics.
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Affiliation(s)
- Benoît Perez‐Lamarque
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, CP39ParisFrance
- Institut de biologie de l'École normale supérieure (IBENS), École normale supérieure, CNRS, INSERM, Université PSLParisFrance
| | - Liam Laurent‐Webb
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, CP39ParisFrance
| | - Amélia Bourceret
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, CP39ParisFrance
| | - Louis Maillet
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, CP39ParisFrance
| | | | - Denis Cartier
- Pôle Lorrain du Futur Conservatoire Botanique National Nord‐Est, Jardin botanique Jean‐Marie PeltVillers‐lès‐NancyFrance
| | - François Labolle
- Université de Strasbourg, Faculté des Sciences de la Vie, Institut de BotaniqueStrasbourgFrance
| | - Pascal Holveck
- Réseau National Habitats‐Flore, Office National des Forêts (ONF)ParisFrance
| | - Didier Epp
- Office National des Forêts (ONF), Service environnement et planification forestièreSchirmeckFrance
| | - Marc‐André Selosse
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'histoire naturelle, CNRS, Sorbonne Université, EPHE, UA, CP39ParisFrance
- Department of Plant Taxonomy and Nature ConservationUniversity of GdanskGdanskPoland
- Institut universitaire de France (IUF)ParisFrance
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Fernández M, Kaur J, Sharma J. Co-occurring epiphytic orchids have specialized mycorrhizal fungal niches that are also linked to ontogeny. MYCORRHIZA 2023; 33:87-105. [PMID: 36651985 DOI: 10.1007/s00572-022-01099-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/13/2022] [Indexed: 06/17/2023]
Abstract
Mycorrhizal symbiosis has been related to the coexistence and community assembly of coexisting orchids in few studies despite their obligate dependence on mycorrhizal partners to establish and survive. In hyper-diverse environments like tropical rain forests, coexistence of epiphytic orchids may be facilitated through mycorrhizal fungal specialization (i.e., sets of unique and dominant mycorrhizal fungi associated with a particular host species). However, information on the role of orchid mycorrhizal fungi (OMF) in niche differentiation and coexistence of epiphytic orchids is still scarce. In this study, we sought to identify the variation in fungal preferences of four co-occurring epiphytic orchids in a tropical rainforest in Costa Rica by addressing the identity and composition of their endophytic fungal and OMF communities across species and life stages. We show that the endophytic fungal communities are formed mainly of previously recognized OMF taxa, and that the four coexisting orchid species have both a set of shared mycorrhizal fungi and a group of fungi unique to an orchid species. We also found that adult plants keep the OMF of the juvenile stage while adding new mycobionts over time. This study provides evidence for the utilization of specific OMF that may be involved in niche segregation, and for an aggregation mechanism where adult orchids keep initial fungal mycobionts of the juvenile stage while adding others.
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Affiliation(s)
- Melania Fernández
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA.
- Lankester Botanical Garden, University of Costa Rica, Cartago, 30109, Costa Rica.
- Herbarium UCH, Universidad Autónoma de Chiriquí, David, Chiriquí, Panama.
| | - Jaspreet Kaur
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA
| | - Jyotsna Sharma
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA
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Liu H, Jacquemyn H, Yu S, Chen W, He X, Huang Y. Mycorrhizal diversity and community composition in co-occurring Cypripedium species. MYCORRHIZA 2023; 33:107-118. [PMID: 36396734 DOI: 10.1007/s00572-022-01095-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
Orchids commonly rely on mycorrhizal fungi to obtain the necessary resources for seed germination and growth. Whereas most photosynthetic orchids typically associate with so-called rhizoctonia fungi to complete their life cycle, there is increasing evidence that other fungi may be involved as well and that the mycorrhizal communities associated with orchids may be more diverse. Coexisting orchid species also tend to associate with different fungi to reduce competition for similar resources and to increase long-term population viability. However, few studies have related the mycorrhizal communities in the rhizosphere to communities found in the roots of closely related coexisting orchid species. In this study, we used high-throughput sequencing to investigate the diversity and community composition of orchid mycorrhizal fungi in the roots and the rhizosphere of four Cypripedium species growing in forests in Northeast China. The results showed that the investigated Cypripedium species associated with a wide variety of fungi including members of Tulasnellaceae, Psathyrellaceae, and Herpotrichiellaceae, whereas members of Russulaceae, Cortinariaceae, Thelephoraceae, and Herpotrichiellaceae showed high abundance in rhizosphere soils. The diversity of fungi detected in the rhizosphere soil was much higher than that in the roots. The observed variation in fungal communities in Cypripedium roots was not related to forest site or orchid species. On the other hand, variation in mycorrhizal communities of rhizosphere soil was significantly related to sampling site. These results indicate that orchid mycorrhizal communities in the rhizosphere display considerable variation among sites and that orchids use only a subset of the locally available fungi. Future studies focusing on the fine-scale spatial distribution of orchid mycorrhizal fungi and more detailed assessments of local environmental conditions will provide novel insights into the mechanisms explaining variation of fungal communities in both orchid roots and the rhizosphere.
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Affiliation(s)
- Huanchu Liu
- Lushan Botanical Garden, Jiangxi Province and Chinese Academy of Sciences, Jiangxi, 332900, China
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, B-3001, Belgium
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, B-3001, Belgium
| | - Shuai Yu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
- Shenyang Arboretum, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Wei Chen
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China.
- Shenyang Arboretum, Chinese Academy of Sciences, Shenyang, 110016, China.
- Key Laboratory of Forest Ecology and Management, Chinese Academy of Sciences, Shenyang, 110016, China.
| | - Xingyuan He
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
- Shenyang Arboretum, Chinese Academy of Sciences, Shenyang, 110016, China
- Key Laboratory of Forest Ecology and Management, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Yanqing Huang
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, China
- Shenyang Arboretum, Chinese Academy of Sciences, Shenyang, 110016, China
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Kolanowska M, Michalska E. The effect of global warming on the Australian endemic orchid Cryptostylis leptochila and its pollinator. PLoS One 2023; 18:e0280922. [PMID: 36716308 PMCID: PMC9886262 DOI: 10.1371/journal.pone.0280922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 01/11/2023] [Indexed: 02/01/2023] Open
Abstract
Ecological stability together with the suitability of abiotic conditions are crucial for long-term survival of any organism and the maintenance of biodiversity and self-sustainable ecosystems relies on species interactions. By influencing resource availability plants affect the composition of plant communities and ultimately ecosystem functioning. Plant-animal interactions are very complex and include a variety of exploitative and mutualistic relationships. One of the most important mutualistic interactions is that between plants and their pollinators. Coevolution generates clustered links between plants and their pollen vectors, but the pollination and reproductive success of plants is reduced by increase in the specialization of plant-animal interactions. One of the most specialized types of pollination is sexual deception, which occurs almost exclusively in Orchidaceae. In this form of mimicry, male insects are attracted to orchid flowers by chemical compounds that resemble insect female sex pheromones and pollinate the flowers during attempted copulations. These interactions are often species-specific with each species of orchid attracting only males of one or very few closely related species of insects. For sexually deceptive orchids the presence of a particular pollen vector is crucial for reproductive success and any reduction in pollinator availability constitutes a threat to the orchid. Because global warming is rapidly becoming the greatest threat to all organisms by re-shaping the geographical ranges of plants, animals and fungi, this paper focuses on predicting the effect of global warming on Cryptostylis leptochila, a terrestrial endemic in eastern Australia that is pollinated exclusively via pseudo copulation with Lissopimpla excelsa. As a species with a single pollinator this orchid is a perfect model for studies on the effect of global warming on plants and their pollen vectors. According to our predictions, global warming will cause a significant loss of suitable niches for C. leptochila. The potential range of this orchid will be 36%-75% smaller than currently and as a result the Eastern Highlands will become unsuitable for C. leptochila. On the other hand, some new niches will become available for this species in Tasmania. Simultaneously, climate change will result in a substantial expansion of niches suitable for the pollinator (44-82%). Currently ca. 71% of the geographical range of the orchid is also suitable for L. excelsa, therefore, almost 30% of the areas occupied by C. leptochila already lack the pollen vector. The predicted availability of the pollen vector increased under three of the climate change scenarios analysed. The predicted habitat loss is a serious threat to this orchid even with the potential colonization of Tasmania by this plant. In the reduced range of C. leptochila the pollen vector will also be present assuring fruit set in populations of this orchid. The genetic pool of the populations in New South Wales and Queensland will probably be lost.
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Affiliation(s)
- Marta Kolanowska
- Faculty of Biology and Environmental Protection, Department of Geobotany and Plant Ecology, University of Lodz, Poland
- * E-mail:
| | - Ewa Michalska
- Faculty of Biology and Environmental Protection, Department of Geobotany and Plant Ecology, University of Lodz, Poland
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Yao N, Wang T, Cao X. Epidendrumradicans Fungal Community during Ex Situ Germination and Isolation of Germination-Enhancing Fungi. Microorganisms 2022; 10:microorganisms10091841. [PMID: 36144443 PMCID: PMC9503211 DOI: 10.3390/microorganisms10091841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/09/2022] [Accepted: 08/30/2022] [Indexed: 11/19/2022] Open
Abstract
Orchids exhibit varying specificities to fungi in different microbial environments. This pilot study investigated the preference of fungal recruitment during symbiotic germination of Epidendrum radicans Pav. ex Lindl. Two different orchid substrates were used for ex situ seed baiting: pine bark and rotten oak leaf, with Basidiomycota and Ascomycota as the respective dominant groups. Both substrates promoted seed germination, with a higher protocorm formation rate on pine bark (65.75%). High-throughput sequencing characterized the fungal communities of germinated protocorms. Basidiomycota was the dominant group in protocorms that symbiotically germinated on both substrates. The family-level community structures of endophytic fungi in protocorms that symbiotically germinated on both substrates were close to those of protocorms that germinated in vitro on MS1 medium. For protocorms, the dominant fungal groups recruited from substrates differed at the genus level; from pine bark, they were genera belonging to unclassified Sebacinales (41.34%), Thanatephorus (14.48%) and Fusarium (7.35%), while, from rotten oak leaf, they were Rhizoctonia (49.46%), Clitopilus (34.61%), and Oliveonia (7.96%). Four fungal isolates were successfully obtained and identified as belonging to the family Tulasnellaceae, genera Ceratobasidium and Peniophora, which could promote seed germination to the seedling stage. The data indicate that endophytic fungi for E. radicans germination on two different substrates are affected at the genus level by the substrate, with a degree of specificity at the family level.
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Affiliation(s)
- Na Yao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Tao Wang
- Beijing Laboratory of Urban and Rural Ecological Environment, Beijing Floriculture Engineering Technology Research Centre, China National Botanical Garden, Beijing 100093, China
| | - Xiaolu Cao
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
- Correspondence:
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Tang YJ, Zhou DY, Dai J, Li Y, Xing YM, Guo SX, Chen J. Potential Specificity Between Mycorrhizal Fungi Isolated from Widespread Dendrobium spp. and Rare D. huoshanense Seeds. Curr Microbiol 2022; 79:264. [PMID: 35859013 DOI: 10.1007/s00284-022-02952-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 06/24/2022] [Indexed: 11/28/2022]
Abstract
In nature, orchid seed germination and seedling development depend on compatible mycorrhizal fungi. Mycorrhizal generalist and specificity affect the orchid distribution and rarity. Here, we investigated the specificity toward fungi in the rare D. huoshanense by mycorrhizal fungal isolation and symbiotic germination in vitro. Twenty mycorrhizal fungal strains were isolated from the roots of adult Dendrobium spp. (six and 12 strains from rare D. huoshanense and widespread D. officinale, respectively, and two strains from D. nobile and D. moniliforme, respectively) and 13 strains belong to Tulasnellaceae and seven strains belong to Serendipitaceae. Germination trials in vitro revealed that all 20 tested fungal strains can stimulate seed germination of D. huoshanense, but only nine strains (~ 50%) can support it up to the seedling stage. This finding indicates that generalistic fungi are important for early germination, but only a few can maintain a symbiosis with host in seedling stage. Thus, a shift of the microbial community from seedling to mature stage probably narrows the D. huoshanense distribution range. In addition, to further understand the relationship between the fungal capability to promote seed germination and fungal enzyme activity, we screened the laccase and pectase activity. The results showed that the two enzymes activities of fungi cannot be directly correlated with their germination-promoting activities. Understanding the host specificity degree toward fungi can help to better interpret the limited geographic distribution of D. huoshanense and provides opportunities for in situ and ex situ conservation and reintroduction programs.
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Affiliation(s)
- Yan-Jing Tang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Dong-Yu Zhou
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Jun Dai
- Anhui Engineering Laboratory for Conservation and Sustainable Utilization for Traditional Chinese Medicine Resources, West Anhui University, Lu'an, 237012, Anhui, China.,College of Biological and Pharmaceutical Engineering, West Anhui University, Lu'an, 237012, Anhui, China
| | - Yang Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Yong-Mei Xing
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Shun-Xing Guo
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Juan Chen
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China.
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11
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Bae EK, An C, Kang MJ, Lee SA, Lee SJ, Kim KT, Park EJ. Chromosome-level genome assembly of the fully mycoheterotrophic orchid Gastrodia elata. G3 (BETHESDA, MD.) 2022; 12:6511440. [PMID: 35100375 PMCID: PMC8896018 DOI: 10.1093/g3journal/jkab433] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 12/10/2021] [Indexed: 11/26/2022]
Abstract
Gastrodia elata, an obligate mycoheterotrophic orchid, requires complete carbon and mineral nutrient supplementation from mycorrhizal fungi during its entire life cycle. Although full mycoheterotrophy occurs most often in the Orchidaceae family, no chromosome-level reference genome from this group has been assembled to date. Here, we report a high-quality chromosome-level genome assembly of G. elata, using Illumina and PacBio sequencing methods with Hi-C technique. The assembled genome size was found to be 1045 Mb, with an N50 of 50.6 Mb and 488 scaffolds. A total of 935 complete (64.9%) matches to the 1440 embryophyte Benchmarking Universal Single-Copy Orthologs were identified in this genome assembly. Hi-C scaffolding of the assembled genome resulted in 18 pseudochromosomes, 1008 Mb in size and containing 96.5% of the scaffolds. A total of 18,844 protein-coding sequences (CDSs) were predicted in the G. elata genome, of which 15,619 CDSs (82.89%) were functionally annotated. In addition, 74.92% of the assembled genome was found to be composed of transposable elements. Phylogenetic analysis indicated a significant contraction of genes involved in various biosynthetic processes and cellular components and an expansion of genes for novel metabolic processes and mycorrhizal association. This result suggests an evolutionary adaptation of G. elata to a mycoheterotrophic lifestyle. In summary, the genomic resources generated in this study will provide a valuable reference genome for investigating the molecular mechanisms of G. elata biological functions. Furthermore, the complete G. elata genome will greatly improve our understanding of the genetics of Orchidaceae and its mycoheterotrophic evolution.
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Affiliation(s)
- Eun-Kyung Bae
- Forest Microbiology Division, National Institute of Forest Science, Suwon 16631, Korea
| | - Chanhoon An
- Forest Microbiology Division, National Institute of Forest Science, Suwon 16631, Korea
| | - Min-Jeong Kang
- Forest Microbiology Division, National Institute of Forest Science, Suwon 16631, Korea
| | - Sang-A Lee
- Forest Microbiology Division, National Institute of Forest Science, Suwon 16631, Korea
| | - Seung Jae Lee
- Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea
| | - Ki-Tae Kim
- Department of Agricultural Life Science, Sunchon National University, Suncheon 57922, Korea
| | - Eung-Jun Park
- Forest Microbiology Division, National Institute of Forest Science, Suwon 16631, Korea
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12
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Selosse MA, Petrolli R, Mujica MI, Laurent L, Perez-Lamarque B, Figura T, Bourceret A, Jacquemyn H, Li T, Gao J, Minasiewicz J, Martos F. The Waiting Room Hypothesis revisited by orchids: were orchid mycorrhizal fungi recruited among root endophytes? ANNALS OF BOTANY 2022; 129:259-270. [PMID: 34718377 PMCID: PMC8835631 DOI: 10.1093/aob/mcab134] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/25/2021] [Indexed: 05/17/2023]
Abstract
BACKGROUND As in most land plants, the roots of orchids (Orchidaceae) associate with soil fungi. Recent studies have highlighted the diversity of the fungal partners involved, mostly within Basidiomycotas. The association with a polyphyletic group of fungi collectively called rhizoctonias (Ceratobasidiaceae, Tulasnellaceae and Serendipitaceae) is the most frequent. Yet, several orchid species target other fungal taxa that differ from rhizoctonias by their phylogenetic position and/or ecological traits related to their nutrition out of the orchid roots (e.g. soil saprobic or ectomycorrhizal fungi). We offer an evolutionary framework for these symbiotic associations. SCOPE Our view is based on the 'Waiting Room Hypothesis', an evolutionary scenario stating that mycorrhizal fungi of land flora were recruited from ancestors that initially colonized roots as endophytes. Endophytes biotrophically colonize tissues in a diffuse way, contrasting with mycorrhizae by the absence of morphological differentiation and of contribution to the plant's nutrition. The association with rhizoctonias is probably the ancestral symbiosis that persists in most extant orchids, while during orchid evolution numerous secondary transitions occurred to other fungal taxa. We suggest that both the rhizoctonia partners and the secondarily acquired ones are from fungal taxa that have broad endophytic ability, as exemplified in non-orchid roots. We review evidence that endophytism in non-orchid plants is the current ecology of many rhizoctonias, which suggests that their ancestors may have been endophytic in orchid ancestors. This also applies to the non-rhizoctonia fungi that were secondarily recruited by several orchid lineages as mycorrhizal partners. Indeed, from our review of the published literature, they are often detected, probably as endophytes, in extant rhizoctonia-associated orchids. CONCLUSION The orchid family offers one of the best documented examples of the 'Waiting Room Hypothesis': their mycorrhizal symbioses support the idea that extant mycorrhizal fungi have been recruited among endophytic fungi that colonized orchid ancestors.
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Affiliation(s)
- Marc-André Selosse
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
- Department of Plant Taxonomy and Nature Conservation, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Rémi Petrolli
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
| | - María Isabel Mujica
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
- Departamento de Ecología, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile, & Instituto de Ecología and Biodiversidad (IEB), Alameda 340, Santiago, Chile
| | - Liam Laurent
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
| | - Benoît Perez-Lamarque
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, 46 rue d’Ulm, 75005 Paris, France
| | - Tomáš Figura
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, 128 44, Prague, Czech Republic
| | - Amelia Bourceret
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Taiqiang Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Jiangyun Gao
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Julita Minasiewicz
- Department of Plant Taxonomy and Nature Conservation, University of Gdańsk, Wita Stwosza 59, 80-308, Gdańsk, Poland
| | - Florent Martos
- Institut de Systématique, Évolution, Biodiversité (UMR 7205 – CNRS, MNHN, UPMC, EPHE), Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, 75005 Paris, France
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13
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Li YY, Boeraeve M, Cho YH, Jacquemyn H, Lee YI. Mycorrhizal Switching and the Role of Fungal Abundance in Seed Germination in a Fully Mycoheterotrophic Orchid, Gastrodia confusoides. FRONTIERS IN PLANT SCIENCE 2022; 12:775290. [PMID: 35095954 PMCID: PMC8792533 DOI: 10.3389/fpls.2021.775290] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Mycorrhizal associations are essential for orchid germination and seedling establishment, and thus may constrain the distribution and abundance of orchids under natural conditions. Previous studies have shown that germination and seedling establishment in several orchids often decline with increasing distance from adult plants, resulting in non-random spatial patterns of seedling establishment. In contrast, individuals of the fully mycoheterotrophic orchid Gastrodia confusoides often tend to have random aboveground spatial patterns of distribution within bamboo forests. Since G. confusoides is parasitic on litter-decaying fungi, its random spatial patterns of distribution may be due to highly scattered patterns of litter-decaying fungi within bamboo forests. To test this hypothesis, we first identified the main mycorrhizal fungi associating with developing seeds and adult plants at a bamboo forest site in Taiwan using Miseq high-throughput DNA sequencing. Next, we combined seed germination experiments with quantitative PCR (qPCR) analyses to investigate to what extent the abundance of mycorrhizal fungi affected spatial patterns of seed germination. Our results show that seed germination and subsequent growth to an adult stage in G. confusoides required a distinct switch in mycorrhizal partners, in which protocorms associated with a single Mycena OTU, while adults mainly associated with an OTU from the genus Gymnopus. A strong, positive relationship was observed between germination and Mycena abundance in the litter, but not between germination and Gymnopus abundance. Fungal abundance was not significantly related to the distance from the adult plants, and consequently germination was also not significantly related to the distance from adult plants. Our results provide the first evidence that the abundance of litter-decaying fungi varies randomly within the bamboo forest and independently from G. confusoides adults.
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Affiliation(s)
- Yuan-Yuan Li
- Beijing Key Laboratory of Seed Disease Testing and Control, College of Plant Protection, China Agricultural University, Beijing, China
| | - Margaux Boeraeve
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
| | - Yu-Hsiu Cho
- Biology Department, National Museum of Natural Science, Taichung, Taiwan
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
| | - Yung-I Lee
- Department of Life Science, National Taiwan University, Taipei, Taiwan
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14
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Rammitsu K, Kajita T, Imai R, Ogura-Tsujita Y. Strong primer bias for Tulasnellaceae fungi in metabarcoding: Specific primers improve the characterization of the mycorrhizal communities of epiphytic orchids. MYCOSCIENCE 2021; 62:356-363. [PMID: 37090180 PMCID: PMC9721509 DOI: 10.47371/mycosci.2021.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 06/18/2021] [Accepted: 06/20/2021] [Indexed: 01/25/2023]
Abstract
Primer bias toward Tulasnellaceae fungi during PCR is a known issue with metabarcoding analyses for the assessment of orchid mycorrhizal communities. However, this bias had not been evaluated for the fungal communities of epiphytic orchids, which account for 69% of all orchid species diversity. We compared the mycorrhizal communities detected using two primer pairs, a fungal universal primer pair (ITS86F/ITS4) and Tulasnella-specific primer pair (5.8STulngs/ITS4-Tul2), using a mock community of fungal isolates from epiphytic orchids and also environmental samples, including orchid roots and a tree bark tip from the host tree of an epiphytic orchid collected. The detected mycorrhizal communities differed widely depending on the primer pairs used. The fungal universal primer pair successfully identified Ceratobasidiaceae and Serendipitaceae fungi but did not reflect Tulasnellaceae diversity. Tulasnellaceae fungi were mainly detected using the Tulasnella-specific primer pair. These tendencies were observed in both the mock community and environmental samples. These results strongly suggest that the use of a Tulasnella-specific primer in combination with a fungal universal primer is essential for assessing the mycorrhizal communities of orchids through metabarcoding analysis, especially in epiphytic orchids. Our study contributes to further understanding of the diversity of mycorrhizal fungi in orchids.
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Affiliation(s)
| | - Tadashi Kajita
- The United Graduate School of Agricultural Sciences, Kagoshima University
| | - Ryosuke Imai
- Tropical Biosphere Research Center, University of the Ryukyus
| | - Yuki Ogura-Tsujita
- The United Graduate School of Agricultural Sciences, Kagoshima University
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15
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Freestone MW, Swarts ND, Reiter N, Tomlinson S, Sussmilch FC, Wright MM, Holmes GD, Phillips RD, Linde CC. Continental-scale distribution and diversity of Ceratobasidium orchid mycorrhizal fungi in Australia. ANNALS OF BOTANY 2021; 128:329-343. [PMID: 34077492 PMCID: PMC8389474 DOI: 10.1093/aob/mcab067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 05/29/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND AIMS Mycorrhizal fungi are a critical component of the ecological niche of most plants and can potentially constrain their geographical range. Unlike other types of mycorrhizal fungi, the distributions of orchid mycorrhizal fungi (OMF) at large spatial scales are not well understood. Here, we investigate the distribution and diversity of Ceratobasidium OMF in orchids and soils across the Australian continent. METHODS We sampled 217 Ceratobasidium isolates from 111 orchid species across southern Australia and combined these with 311 Ceratobasidium sequences from GenBank. To estimate the taxonomic diversity of Ceratobasidium associating with orchids, phylogenetic analysis of the ITS sequence locus was undertaken. Sequence data from the continent-wide Australian Microbiome Initiative were used to determine the geographical range of operational taxonomic units (OTUs) detected in orchids, with the distribution and climatic correlates of the two most frequently detected OTUs modelled using MaxEnt. KEY RESULTS We identified 23 Ceratobasidium OTUs associating with Australian orchids, primarily from the orchid genera Pterostylis, Prasophyllum, Rhizanthella and Sarcochilus. OTUs isolated from orchids were closely related to, but distinct from, known pathogenic fungi. Data from soils and orchids revealed that ten of these OTUs occur on both east and west sides of the continent, while 13 OTUs were recorded at three locations or fewer. MaxEnt models suggested that the distributions of two widespread OTUs are correlated with temperature and soil moisture of the wettest quarter and far exceeded the distributions of their host orchid species. CONCLUSIONS Ceratobasidium OMF with cross-continental distributions are common in Australian soils and frequently have geographical ranges that exceed that of their host orchid species, suggesting these fungi are not limiting the distributions of their host orchids at large spatial scales. Most OTUs were distributed within southern Australia, although several OTUs had distributions extending into central and northern parts of the continent, illustrating their tolerance of an extraordinarily wide range of environmental conditions.
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Affiliation(s)
- Marc W Freestone
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Royal Botanic Gardens Victoria, Cranbourne, VIC 3977, Australia
- Biodiversity and Conservation Division, Department of Agriculture, Water and Environment, Canberra, ACT 2600, Australia
| | - Nigel D Swarts
- Tasmanian Institute of Agriculture, The University of Tasmania, Sandy Bay, TAS 7005, Australia
- Royal Tasmanian Botanical Gardens, Hobart, TAS 7000, Australia
| | - Noushka Reiter
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Royal Botanic Gardens Victoria, Cranbourne, VIC 3977, Australia
| | - Sean Tomlinson
- Molecular and Life Sciences, Curtin University, Bentley, WA 6102, Australia
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, West Perth, WA 6005, Australia
| | - Frances C Sussmilch
- Tasmanian Institute of Agriculture, The University of Tasmania, Sandy Bay, TAS 7005, Australia
| | - Magali M Wright
- Royal Tasmanian Botanical Gardens, Hobart, TAS 7000, Australia
| | - Gareth D Holmes
- Royal Botanic Gardens Victoria, Cranbourne, VIC 3977, Australia
| | - Ryan D Phillips
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Royal Botanic Gardens Victoria, Cranbourne, VIC 3977, Australia
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, West Perth, WA 6005, Australia
- Department of Ecology, Environment and Evolution, LaTrobe University, Bundoora, VIC 3086, Australia
| | - Celeste C Linde
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
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16
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Wang D, Jacquemyn H, Gomes SIF, Vos RA, Merckx VSFT. Symbiont switching and trophic mode shifts in Orchidaceae. THE NEW PHYTOLOGIST 2021; 231:791-800. [PMID: 33932029 PMCID: PMC8252101 DOI: 10.1111/nph.17414] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/09/2021] [Indexed: 05/15/2023]
Abstract
Mycorrhizal fungi are central to the biology of land plants. However, to what extent mycorrhizal shifts - broad evolutionary transitions in root-associated fungal symbionts - are related to changes in plant trophic modes remains poorly understood. We built a comprehensive DNA dataset of Orchidaceae fungal symbionts and a dated plant molecular phylogeny to test the hypothesis that shifts in orchid trophic modes follow a stepwise pattern, from autotrophy over partial mycoheterotrophy (mixotrophy) to full mycoheterotrophy, and that these shifts are accompanied by switches in fungal symbionts. We estimate that at least 17 independent shifts from autotrophy towards full mycoheterotrophy occurred in orchids, mostly through an intermediate state of partial mycoheterotrophy. A wide range of fungal partners was inferred to occur in the roots of the common ancestor of this family, including 'rhizoctonias', ectomycorrhizal, and wood- or litter-decaying saprotrophic fungi. Phylogenetic hypothesis tests further show that associations with ectomycorrhizal or saprotrophic fungi were most likely a prerequisite for evolutionary shifts towards full mycoheterotrophy. We show that shifts in trophic mode often coincided with switches in fungal symbionts, suggesting that the loss of photosynthesis selects for different fungal communities in orchids. We conclude that changes in symbiotic associations and ecophysiological traits are tightly correlated throughout the diversification of orchids.
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Affiliation(s)
- Deyi Wang
- Naturalis Biodiversity CenterLeiden2332 AAthe Netherlands
- Institute of BiologyLeiden UniversityLeiden2333 BEthe Netherlands
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population BiologyKU LeuvenKasteelpark Arenberg 31, HeverleeLeuven3001Belgium
| | - Sofia I. F. Gomes
- Naturalis Biodiversity CenterLeiden2332 AAthe Netherlands
- Institute of BiologyLeiden UniversityLeiden2333 BEthe Netherlands
| | - Rutger A. Vos
- Naturalis Biodiversity CenterLeiden2332 AAthe Netherlands
- Institute of BiologyLeiden UniversityLeiden2333 BEthe Netherlands
| | - Vincent S. F. T. Merckx
- Naturalis Biodiversity CenterLeiden2332 AAthe Netherlands
- Department of Evolutionary and Population BiologyInstitute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdam1098 XHthe Netherlands
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17
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Zhao DK, Selosse MA, Wu L, Luo Y, Shao SC, Ruan YL. Orchid Reintroduction Based on Seed Germination-Promoting Mycorrhizal Fungi Derived From Protocorms or Seedlings. FRONTIERS IN PLANT SCIENCE 2021; 12:701152. [PMID: 34276753 PMCID: PMC8278863 DOI: 10.3389/fpls.2021.701152] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 06/04/2021] [Indexed: 06/13/2023]
Abstract
Orchids are among the most endangered in the plant kingdom. Lack of endosperm in their seeds renders orchids to depend on nutrients provided by orchid mycorrhizal fungi (OMF) for seed germination and seedling formation in the wild. OMF that parasitize in germination seeds is an essential element for orchid seedling formation, which can also help orchid reintroduction. Considering the limitations of the previous orchid reintroduction technology based on seed germination-promoting OMF (sgOMF) sourced from orchid roots, an innovative approach is proposed here in which orchid seeds are directly co-sown with sgOMF carrying ecological specificity from protocorms/seedlings. Based on this principle, an integrative and practical procedure concerning related ecological factors is further raised for re-constructing long-term and self-sustained orchid populations. We believe that this new approach will benefit the reintroduction of endangered orchids in nature.
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Affiliation(s)
- Da-Ke Zhao
- Biocontrol Engineering Research Center of Plant Disease and Pest, Biocontrol Engineering Research Center of Crop Disease and Pest, School of Ecology and Environmental Science, Yunnan University, Kunming, China
| | - Marc-André Selosse
- Département Systématique et Evolution, UMR 7205 ISYEB, Muséum National d'Histoire Naturelle, Paris, France
- Faculty of Biology, University of Gdansk, Gdansk, Poland
| | - Limin Wu
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation, Canberra, ACT, Australia
| | - Yan Luo
- Gardening and Horticulture Department, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
| | - Shi-Cheng Shao
- Gardening and Horticulture Department, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
| | - Yong-Ling Ruan
- Australia-China Research Centre for Crop Improvement, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW, Australia
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18
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Ventre Lespiaucq A, Jacquemyn H, Rasmussen HN, Méndez M. Temporal turnover in mycorrhizal interactions: a proof of concept with orchids. THE NEW PHYTOLOGIST 2021; 230:1690-1699. [PMID: 33621346 DOI: 10.1111/nph.17291] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 02/12/2021] [Indexed: 06/12/2023]
Abstract
Temporal turnover events in biotic interactions involving plants are rarely assessed, although such changes might afford a considerable acclimation potential to the plant. This could enable fairly rapid responses to short-term fluctuations in growth conditions as well as lasting responses to long-term climatic trends. Here, we present a classification of temporal turnover encompassing 11 possible scenarios. Using orchid mycorrhiza as a study model, we show that temporal changes are common, and discuss under which conditions temporal turnover of fungal symbiont is expected. We provide six research questions and identify technical challenges that we deem most important for future studies. Finally, we discuss how the same framework can be applied to other types of biotic interactions.
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Affiliation(s)
| | - Hans Jacquemyn
- Plant Conservation and Population Biology, Department of Biology, KU Leuven, Leuven, 3001, Belgium
| | - Hanne N Rasmussen
- Department of Geosciences and Nature Management, Section for Forest, Nature and Biomass, University of Copenhagen, Copenhagen, 1958, Denmark
| | - Marcos Méndez
- Área de Biodiversidad y Conservación, Universidad Rey Juan Carlos, Madrid, 28933, Spain
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19
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Fungal diversity driven by bark features affects phorophyte preference in epiphytic orchids from southern China. Sci Rep 2021; 11:11287. [PMID: 34050223 PMCID: PMC8163780 DOI: 10.1038/s41598-021-90877-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/17/2021] [Indexed: 11/17/2022] Open
Abstract
Epiphytic orchids exhibit varying degrees of phorophyte tree specificity. We performed a pilot study to investigate why epiphytic orchids prefer or avoid certain trees. We selected two orchid species, Panisea uniflora and Bulbophyllum odoratissimum co-occurring in a forest habitat in southern China, where they showed a specific association with Quercus yiwuensis and Pistacia weinmannifolia trees, respectively. We analysed a number of environmental factors potentially influencing the relationship between orchids and trees. Difference in bark features, such as water holding capacity and pH were recorded between Q. yiwuensis and P. weinmannifolia, which could influence both orchid seed germination and fungal diversity on the two phorophytes. Morphological and molecular culture-based methods, combined with metabarcoding analyses, were used to assess fungal communities associated with studied orchids and trees. A total of 162 fungal species in 74 genera were isolated from bark samples. Only two genera, Acremonium and Verticillium, were shared by the two phorophyte species. Metabarcoding analysis confirmed the presence of significantly different fungal communities on the investigated tree and orchid species, with considerable similarity between each orchid species and its host tree, suggesting that the orchid-host tree association is influenced by the fungal communities of the host tree bark.
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20
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Li T, Wu S, Yang W, Selosse MA, Gao J. How Mycorrhizal Associations Influence Orchid Distribution and Population Dynamics. FRONTIERS IN PLANT SCIENCE 2021; 12:647114. [PMID: 34025695 PMCID: PMC8138319 DOI: 10.3389/fpls.2021.647114] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/13/2021] [Indexed: 05/04/2023]
Abstract
Orchid distribution and population dynamics are influenced by a variety of ecological factors and the formation of holobionts, which play key roles in colonization and ecological community construction. Seed germination, seedling establishment, reproduction, and survival of orchid species are strongly dependent on orchid mycorrhizal fungi (OMF), with mycorrhizal cheating increasingly observed in photosynthetic orchids. Therefore, changes in the composition and abundance of OMF can have profound effects on orchid distribution and fitness. Network analysis is an important tool for the study of interactions between plants, microbes, and the environment, because of the insights that it can provide into the interactions and coexistence patterns among species. Here, we provide a comprehensive overview, systematically describing the current research status of the effects of OMF on orchid distribution and dynamics, phylogenetic signals in orchid-OMF interactions, and OMF networks. We argue that orchid-OMF associations exhibit complementary and specific effects that are highly adapted to their environment. Such specificity of associations may affect the niche breadth of orchid species and act as a stabilizing force in plant-microbe coevolution. We postulate that network analysis is required to elucidate the functions of fungal partners beyond their effects on germination and growth. Such studies may lend insight into the microbial ecology of orchids and provide a scientific basis for the protection of orchids under natural conditions in an efficient and cost-effective manner.
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Affiliation(s)
- Taiqiang Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Shimao Wu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Wenke Yang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Marc-André Selosse
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
- Institut de Systématique, Évolution, Biodiversité, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum National d’Histoire Naturelle, Sorbonne Universités, Paris, France
- Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Jiangyun Gao
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
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21
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Li T, Yang W, Wu S, Selosse MA, Gao J. Progress and Prospects of Mycorrhizal Fungal Diversity in Orchids. FRONTIERS IN PLANT SCIENCE 2021; 12:646325. [PMID: 34025694 PMCID: PMC8138444 DOI: 10.3389/fpls.2021.646325] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 04/12/2021] [Indexed: 05/03/2023]
Abstract
Orchids form mycorrhizal symbioses with fungi in natural habitats that affect their seed germination, protocorm growth, and adult nutrition. An increasing number of studies indicates how orchids gain mineral nutrients and sometime even organic compounds from interactions with orchid mycorrhizal fungi (OMF). Thus, OMF exhibit a high diversity and play a key role in the life cycle of orchids. In recent years, the high-throughput molecular identification of fungi has broadly extended our understanding of OMF diversity, revealing it to be a dynamic outcome co-regulated by environmental filtering, dispersal restrictions, spatiotemporal scales, biogeographic history, as well as the distribution, selection, and phylogenetic spectrum width of host orchids. Most of the results show congruent emerging patterns. Although it is still difficult to extend them to all orchid species or geographical areas, to a certain extent they follow the "everything is everywhere, but the environment selects" rule. This review provides an extensive understanding of the diversity and ecological dynamics of orchid-fungal association. Moreover, it promotes the conservation of resources and the regeneration of rare or endangered orchids. We provide a comprehensive overview, systematically describing six fields of research on orchid-fungal diversity: the research methods of orchid-fungal interactions, the primer selection in high-throughput sequencing, the fungal diversity and specificity in orchids, the difference and adaptability of OMF in different habitats, the comparison of OMF in orchid roots and soil, and the spatiotemporal variation patterns of OMF. Further, we highlight certain shortcomings of current research methodologies and propose perspectives for future studies. This review emphasizes the need for more information on the four main ecological processes: dispersal, selection, ecological drift, and diversification, as well as their interactions, in the study of orchid-fungal interactions and OMF community structure.
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Affiliation(s)
- Taiqiang Li
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Wenke Yang
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Shimao Wu
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
| | - Marc-André Selosse
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
- Institut de Systématique, Évolution, Biodiversité, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum National d’Histoire Naturelle, Sorbonne Universités, Paris, France
- Department of Plant Taxonomy and Nature Conservation, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Jiangyun Gao
- Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology, Yunnan University, Kunming, China
- Laboratory of Ecology and Evolutionary Biology, Yunnan University, Kunming, China
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22
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Yokoya K, Jacob AS, Zettler LW, Kendon JP, Menon M, Bell J, Rajaovelona L, Sarasan V. Fungal Diversity of Selected Habitat Specific Cynorkis Species (Orchidaceae) in the Central Highlands of Madagascar. Microorganisms 2021; 9:microorganisms9040792. [PMID: 33920122 PMCID: PMC8069969 DOI: 10.3390/microorganisms9040792] [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: 03/24/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/17/2022] Open
Abstract
About 90% of Cynorkis species are endemic to the biodiversity hotspot of Madagascar. This terrestrial habitat-specific genus received little study for fungal diversity to support conservation. We evaluated the diversity of culturable fungi of 11 species and soil characteristics from six sites spanning a >40 km radius in and along the region’s inselbergs. Peloton-forming fungi were grown in vitro from root/protocorm slices and positively identified using DNA sequencing. The fungal diversity was then correlated with soil pH, NO3-N, P, and K. All species harbored either putative mycorrhizal associates in the Rhizoctonia complex or Hypocreales fungi. Tulasnella Operational Taxonomic Units (OTUs) were most prevalent in all soil types while Serendipita OTUs were found in species inhabiting granite/rock outcrops in moist soil (seepage areas). Most Cynorkis species were present in soil with low NO3-N and P levels with diversity of mycorrhizal fungi inversely correlated to NO3-N levels. Of the different orchid life stages sampled, only one species (Cynorkis fastigiata) yielded putative mycorrhizal fungi from juvenile stages. As diversity of mycorrhizal fungi of Cynorkis spp. was negatively correlated with NO3-N, and majority of the studied taxa were found in soils with low NO3-N and P contents, reintroduction studies must include analysis of N and P in detail. For the first time, we showed that the assemblage of culturable fungi in the roots of habitat-specific species of Cynorkis (Orchidaceae) are intimately tied to specific soil characteristics.
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Affiliation(s)
- Kazutomo Yokoya
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK; (K.Y.); (A.S.J.); (J.P.K.); (J.B.); (L.R.)
| | - Alison S. Jacob
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK; (K.Y.); (A.S.J.); (J.P.K.); (J.B.); (L.R.)
| | | | - Jonathan P. Kendon
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK; (K.Y.); (A.S.J.); (J.P.K.); (J.B.); (L.R.)
| | - Manoj Menon
- Department of Geography, University of Sheffield, Sheffield S10 2TN, UK;
| | - Jake Bell
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK; (K.Y.); (A.S.J.); (J.P.K.); (J.B.); (L.R.)
| | - Landy Rajaovelona
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK; (K.Y.); (A.S.J.); (J.P.K.); (J.B.); (L.R.)
| | - Viswambharan Sarasan
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3DS, UK; (K.Y.); (A.S.J.); (J.P.K.); (J.B.); (L.R.)
- Correspondence:
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23
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Jacquemyn H, Brys R, Waud M, Evans A, Figura T, Selosse MA. Mycorrhizal Communities and Isotope Signatures in Two Partially Mycoheterotrophic Orchids. FRONTIERS IN PLANT SCIENCE 2021; 12:618140. [PMID: 33633765 PMCID: PMC7901878 DOI: 10.3389/fpls.2021.618140] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/18/2021] [Indexed: 05/20/2023]
Abstract
Partial mycoheterotrophy, the ability of plants to obtain carbon from fungi throughout their life cycle in combination with photosynthesis, appears to be more common within the Plant Kingdom than previously anticipated. Recent studies using stable isotope analyses have indicated that isotope signatures in partially mycoheterotrophic plants vary widely among species, but the relative contributions of family- or species-specific characteristics and the identity of the fungal symbionts to the observed differences remain unclear. Here, we investigated in detail mycorrhizal communities and isotopic signatures in four co-occurring terrestrial orchids (Platanthera chlorantha, Epipactis helleborine, E. neglecta and the mycoheterotrophic Neottia nidus-avis). All investigated species were mycorrhizal generalists (i.e., associated with a large number of fungi simultaneously), but mycorrhizal communities differed significantly between species. Mycorrhizal communities associating with the two Epipactis species consisted of a wide range of fungi belonging to different families, whereas P. chlorantha and N. nidus-avis associated mainly with Ceratobasidiaceae and Sebacinaceae species, respectively. Isotopic signatures differed significantly between both Epipactis species, with E. helleborine showing near autotrophic behavior and E. neglecta showing significant enrichment in both carbon and nitrogen. No significant differences in photosynthesis and stomatal conductance were observed between the two partially mycoheterotrophic orchids, despite significant differences in isotopic signatures. Our results demonstrate that partially mycoheterotrophic orchids of the genus Epipactis formed mycorrhizas with a wide diversity of fungi from different fungal families, but variation in mycorrhizal community composition was not related to isotope signatures and thus transfer of C and N to the plant. We conclude that the observed differences in isotope signatures between E. helleborine and E. neglecta cannot solely be explained by differences in mycorrhizal communities, but most likely reflect a combination of inherent physiological differences and differences in mycorrhizal communities.
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Affiliation(s)
- Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Rein Brys
- Research Institute for Forest and Nature, Geraardsbergen, Belgium
| | - Michael Waud
- Department of Biology, Plant Conservation and Population Biology, Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Alexandra Evans
- Department of Biology, Plant Conservation and Population Biology, Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Tomáš Figura
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Paris, France
- Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Marc-André Selosse
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, Sorbonne Université, EPHE, Paris, France
- Faculty of Biology, University of Gdańsk, Gdańsk, Poland
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24
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Kaur J, Phillips C, Sharma J. Host population size is linked to orchid mycorrhizal fungal communities in roots and soil, which are shaped by microenvironment. MYCORRHIZA 2021; 31:17-30. [PMID: 33113039 DOI: 10.1007/s00572-020-00993-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 10/12/2020] [Indexed: 05/04/2023]
Abstract
Interaction with orchid mycorrhizal fungi (OMF) is essential to all members of the Orchidaceae, yet we know little about whether or how OMF abundances in substrates shape orchid populations. While root-associated OMF diversity is catalogued frequently, technological constraints have impeded the assessments of OMF communities in substrates until recently, thereby limiting the ability to link OMF communities in a habitat to population responses. Furthermore, there is some evidence that edaphic and microclimatic conditions impact OMF in soil, yet we lack an understanding of the coupled influences of abiotic environment and OMF structure on orchid population dynamics. To discover the linkages between abiotic environment, OMF community structure, and population size, we characterized the microclimatic conditions, soil physicochemistry, and OMF communities hosted by roots and soil across large and small populations of a terrestrial orchid endemic to California Floristic Province in North America. By using high-throughput sequencing of the ITS2 region of nrDNA amplified from root and soil DNAs, we determined that both roots and soil of larger populations, which were high in phosphorus but low in zinc, organic matter, and silt, were dominated by Tulasnellaceae OTUs. In comparison, roots and soil from smaller populations of the orchid hosted higher relative abundances of the Ceratobasidiaceae. In this multiyear, range-wide study that simultaneously measured habitat environmental conditions, and soil and root OMF communities, our results suggest that soil chemistry is clearly linked to soil and root OMF communities, which then likely alter and shape orchid populations.
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Affiliation(s)
- Jaspreet Kaur
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, USA.
| | - Caleb Phillips
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Jyotsna Sharma
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, USA
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25
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Pujasatria GC, Miura C, Kaminaka H. In Vitro Symbiotic Germination: A Revitalized Heuristic Approach for Orchid Species Conservation. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1742. [PMID: 33317200 PMCID: PMC7763479 DOI: 10.3390/plants9121742] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/05/2020] [Accepted: 12/08/2020] [Indexed: 11/21/2022]
Abstract
As one of the largest families of flowering plants, Orchidaceae is well-known for its high diversity and complex life cycles. Interestingly, such exquisite plants originate from minute seeds, going through challenges to germinate and establish in nature. Alternatively, orchid utilization as an economically important plant gradually decreases its natural population, therefore, driving the need for conservation. As with any conservation attempts, broad knowledge is required, including the species' interaction with other organisms. All orchids establish mycorrhizal symbiosis with certain lineages of fungi to germinate naturally. Since the whole in situ study is considerably complex, in vitro symbiotic germination study is a promising alternative. It serves as a tool for extensive studies at morphophysiological and molecular levels. In addition, it provides insights before reintroduction into its natural habitat. Here we reviewed how mycorrhiza contributes to orchid lifecycles, methods to conduct in vitro study, and how it can be utilized for conservation needs.
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Affiliation(s)
- Galih Chersy Pujasatria
- Department of Agricultural Science, Graduate School of Sustainable Science, Tottori University, Tottori 680-8553, Japan;
| | - Chihiro Miura
- Faculty of Agriculture, Tottori University, 4-101 Koyama Minami, Tottori 680-8553, Japan;
| | - Hironori Kaminaka
- Faculty of Agriculture, Tottori University, 4-101 Koyama Minami, Tottori 680-8553, Japan;
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26
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Herrera-Rus I, Pastor JE, Juan R. Fungal colonization associated with phenological stages of a photosynthetic terrestrial temperate orchid from the Southern Iberian Peninsula. JOURNAL OF PLANT RESEARCH 2020; 133:807-825. [PMID: 32968931 DOI: 10.1007/s10265-020-01225-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/14/2020] [Indexed: 05/20/2023]
Abstract
Fungal endophytes, both mycorrhizal and non-mycorrhizal, are involved in the development of the life cycle of orchids, providing potential beneficial relationships. Here, we assess the succession of changes in the diversity of fungal symbionts associated with a terrestrial temperate orchid species, Anacamptis morio subsp. champagneuxii, over three phenological stages: developed leaves but no stem elongation, flowering, and fruiting. Fungi endophyte associated with roots were obtained by culture in sterile conditions. A total of 18 morphotypes-one Mortierellomycota, two Basidiomycota and 15 Ascomycota-were differentiated, and were also characterized using PCR and DNA sequencing techniques. Only three of the 18 OTUs are shared among the three phenological stages examined: Westerdykella sp., a member of Ceratobasidiaceae, and Fusarium oxysporum, representing a relative abundance of between 28% (fruiting) to 41% (flowering). Our research confirmed that fungal symbionts varied among the different phenological stages examined, the peak of endophyte diversity appearing in the flowering stage. The availability of a diverse mycobiota seems to be important for the survival of orchid plants because it may cover particular physiological needs, and knowledge concerning this mycobiota is of special relevance in the establishment of reliable conservation programmes.
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Affiliation(s)
- Irene Herrera-Rus
- Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad de Sevilla, Profesor García González, 2, 41012, Sevilla, Spain
| | - Julio E Pastor
- Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Reina Mercedes, 6, 41012, Sevilla, Spain
| | - Rocío Juan
- Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad de Sevilla, Profesor García González, 2, 41012, Sevilla, Spain.
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27
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Shao SC, Luo Y, Jacquemyn H. Co-Cultures of Mycorrhizal Fungi Do Not Increase Germination and Seedling Development in the Epiphytic Orchid Dendrobium nobile. FRONTIERS IN PLANT SCIENCE 2020; 11:571426. [PMID: 33193505 PMCID: PMC7644947 DOI: 10.3389/fpls.2020.571426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 09/29/2020] [Indexed: 05/27/2023]
Abstract
Orchids are highly dependent on mycorrhizal fungi for seed germination and subsequent growth to a seedling as they provide essential carbon, water, and mineral nutrients to developing seeds. Although there is mounting evidence that orchid seeds are often colonized by multiple fungi simultaneously, most in vitro germination experiments focus on mycorrhizal monocultures and little is known about how mycorrhizal assemblages affect seed germination and growth of seedlings. In this study, we compared the effects of mycorrhizal monocultures and co-cultures on seed germination and seedling growth of the epiphytic orchid Dendrobium nobile. In situ baiting was used to isolate mycorrhizal fungi from protocorms for germination experiments. Germination experiments were conducted under two light regimes for 90 days. In total, five fungal strains were isolated from protocorms of D. nobile, indicating that the species was not highly specific to its fungal partners. Four strains (JC-01, JC-02, JC-04, and JC-05) belonged to the Serendipitaceae and one (JC-03) to the Tulasnellaceae. In vitro germination experiments showed that germination percentages were higher under light-dark conditions than under complete dark conditions, supporting previous findings that light facilitates germination in epiphytic orchids. While all strains were able to induce protocorm formation and growth into the seedling stage, large differences between fungal strains were observed. Co-cultures did not result in significantly higher seed germination percentages and seedling development than monocultures. Taken together, these results demonstrate that effects of fungal assemblages are not predictable from those of component species, and that more work is needed to better understand the role of fungal assemblages determining seed germination and subsequent growth under natural conditions.
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Affiliation(s)
- Shi-Cheng Shao
- Gardening and Horticulture Department, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
| | - Yan Luo
- Gardening and Horticulture Department, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
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28
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Ecological niche modeling of the pantropical orchid Polystachya concreta (Orchidaceae) and its response to climate change. Sci Rep 2020; 10:14801. [PMID: 32908206 PMCID: PMC7481249 DOI: 10.1038/s41598-020-71732-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 08/19/2020] [Indexed: 01/11/2023] Open
Abstract
Climate is the dominant control factor on the spatial distribution of organisms on a global scale and global warming is predicted to become a major cause of species extinctions. In our study ecological niche modeling (ENM) was used to estimate the effect of projected future climate changes on the pantropical orchid Polystacha concreta as well as to reconstruct changes in the distribution of the suitable climatic niches of this species since the Last Glacial Maximum (LGM). The study revealed small differences in the niches occupied by populations of P. concreta recorded in various continents; however, these alterations will become more significant in regard to future climatic change. While losses of suitable habitats of the studied orchid will occur in the Americas and Africa, global warming will be favorable for Asian populations. Our study suggests a significant loss of niches since the LGM which indicates that the currently observed loss of habitats is not only the result of human activity but also of natural changes of the Earth’s climate. From the obtained models we identified the areas that will be the most resistant regarding the modifications caused by climate change.
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29
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Phillips RD, Reiter N, Peakall R. Orchid conservation: from theory to practice. ANNALS OF BOTANY 2020; 126:345-362. [PMID: 32407498 PMCID: PMC7424752 DOI: 10.1093/aob/mcaa093] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/07/2020] [Indexed: 05/21/2023]
Abstract
BACKGROUND Given the exceptional diversity of orchids (26 000+ species), improving strategies for the conservation of orchids will benefit a vast number of taxa. Furthermore, with rapidly increasing numbers of endangered orchids and low success rates in orchid conservation translocation programmes worldwide, it is evident that our progress in understanding the biology of orchids is not yet translating into widespread effective conservation. SCOPE We highlight unusual aspects of the reproductive biology of orchids that can have important consequences for conservation programmes, such as specialization of pollination systems, low fruit set but high seed production, and the potential for long-distance seed dispersal. Further, we discuss the importance of their reliance on mycorrhizal fungi for germination, including quantifying the incidence of specialized versus generalized mycorrhizal associations in orchids. In light of leading conservation theory and the biology of orchids, we provide recommendations for improving population management and translocation programmes. CONCLUSIONS Major gains in orchid conservation can be achieved by incorporating knowledge of ecological interactions, for both generalist and specialist species. For example, habitat management can be tailored to maintain pollinator populations and conservation translocation sites selected based on confirmed availability of pollinators. Similarly, use of efficacious mycorrhizal fungi in propagation will increase the value of ex situ collections and likely increase the success of conservation translocations. Given the low genetic differentiation between populations of many orchids, experimental genetic mixing is an option to increase fitness of small populations, although caution is needed where cytotypes or floral ecotypes are present. Combining demographic data and field experiments will provide knowledge to enhance management and translocation success. Finally, high per-fruit fecundity means that orchids offer powerful but overlooked opportunities to propagate plants for experiments aimed at improving conservation outcomes. Given the predictions of ongoing environmental change, experimental approaches also offer effective ways to build more resilient populations.
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Affiliation(s)
- Ryan D Phillips
- Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, Victoria, Australia
- Kings Park Science, Department of Biodiversity Conservation and Attractions, Kings Park, WA, Australia
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Noushka Reiter
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- Royal Botanic Gardens Victoria, Corner of Ballarto Road and Botanic Drive, Cranbourne, VIC, Australia
| | - Rod Peakall
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, Australia
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30
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Downing JL, Liu H, McCormick MK, Arce J, Alonso D, Lopez‐Perez J. Generalized mycorrhizal interactions and fungal enemy release drive range expansion of orchids in southern Florida. Ecosphere 2020. [DOI: 10.1002/ecs2.3228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Jason L. Downing
- International Center for Tropical Botany Florida International University 11200 8th Street Miami Florida33199USA
- Fairchild Tropical Botanic Garden 10901 Old Cutler Road Coral Gables Florida33156USA
| | - Hong Liu
- International Center for Tropical Botany Florida International University 11200 8th Street Miami Florida33199USA
- Fairchild Tropical Botanic Garden 10901 Old Cutler Road Coral Gables Florida33156USA
| | - Melissa K. McCormick
- Smithsonian Institution Smithsonian Environmental Research Center 647 Contees Wharf Road Edgewater Maryland21037USA
| | - Jay Arce
- International Center for Tropical Botany Florida International University 11200 8th Street Miami Florida33199USA
- Fairchild Tropical Botanic Garden 10901 Old Cutler Road Coral Gables Florida33156USA
| | - Dailen Alonso
- International Center for Tropical Botany Florida International University 11200 8th Street Miami Florida33199USA
| | - Jorge Lopez‐Perez
- International Center for Tropical Botany Florida International University 11200 8th Street Miami Florida33199USA
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31
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Is the Distribution of Two Rare Orchis Sister Species Limited by Their Main Mycobiont? DIVERSITY 2020. [DOI: 10.3390/d12070262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
As orchids rely on their mycorrhizal fungi for nutrient supply, their spatial range is dependent on the distribution of orchid mycorrhizal (OM) fungi. We addressed possible correlations between mycorrhizal specificity and the geographic distribution of orchids and OM fungi in three populations of the rare sister species Orchis patens and O. canariensis. Metabarcoding of the fungal ITS2 region indicated that, although adult plants of either species were colonized by several ceratobasidioid, tulasnelloid, sebacinoid and serendipitoid fungi, the mycobiont spectra were dominated by Tulasnella helicospora (which occurred in 100% of examined plants with high read numbers), which is a globally distributed fungus. In vitro assays with a T. helicospora isolate obtained from O. patens indicated the effectiveness of this OM fungus at germinating seeds of its native host. At a local scale, higher read numbers for T. helicospora were found in soil samples collected underneath O. patens roots than at locations unoccupied by the orchid. Although these findings suggest that the geographical pattern of the main fungal symbiont does not limit the distribution of O. patens and O. canariensis at this scale, the actual causal link between orchid and OM fungal occurrence/abundance still needs to be better understood.
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32
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Tsiftsis S, Djordjević V. Modelling sexually deceptive orchid species distributions under future climates: the importance of plant-pollinator interactions. Sci Rep 2020; 10:10623. [PMID: 32606363 PMCID: PMC7327032 DOI: 10.1038/s41598-020-67491-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/04/2020] [Indexed: 12/03/2022] Open
Abstract
Biotic interactions play an important role in species distribution models, whose ignorance may cause an overestimation of species' potential distributions. Species of the family Orchidaceae are almost totally dependent on mycorrhizal symbionts and pollinators, with sexually deceptive orchids being often highly specialized, and thus the interactions with their pollinators are expected to strongly affect distribution predictions. We used Maxent algorithm to explore the extent of current and future habitat suitability for two Greek endemic sexually deceptive orchids (Ophrys argolica and Ophrys delphinensis) in relation to the potential distribution of their unique pollinator (Anthophora plagiata). Twelve climate change scenarios were used to predict future distributions. Results indicated that the most important factors determining potential distribution were precipitation seasonality for O. argolica and geological substrate for O. delphinensis. The current potential distribution of the two orchids was almost of the same extent but spatially different, without accounting for their interaction with A. plagiata. When the interaction was included in the models, their potentially suitable area decreased for both species. Under future climatic conditions, the effects of the orchid-pollinator interaction were more intense. Specifically, O. argolica was restricted in specific areas of southern Greece, whereas O. delphinensis was expected to become extinct. Our findings highlighted the significant role of plant–pollinator interactions in species distribution models. Failing to study such interactions might expose plant species to serious conservation issues.
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Affiliation(s)
- Spyros Tsiftsis
- Department of Forest and Natural Environment Sciences, International Hellenic University, 1st km Dramas-Microchoriou, 66100, Drama, Greece. .,Global Change Research Institute, Academy of Science of the Czech Republic, Bělidla 986/4a, 603 00, Brno, Czech Republic.
| | - Vladan Djordjević
- Faculty of Biology, Institute of Botany and Botanical Garden, University of Belgrade, Takovska 43, 11 000, Belgrade, Serbia
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Relative effectiveness of Tulasnella fungal strains in orchid mycorrhizal symbioses between germination and subsequent seedling growth. Symbiosis 2020. [DOI: 10.1007/s13199-020-00681-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Gao Y, Zhao Z, Li J, Liu N, Jacquemyn H, Guo S, Xing X. Do fungal associates of co-occurring orchids promote seed germination of the widespread orchid species Gymnadenia conopsea? MYCORRHIZA 2020; 30:221-228. [PMID: 32146514 DOI: 10.1007/s00572-020-00943-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/27/2020] [Indexed: 05/04/2023]
Abstract
Interactions with mycorrhizal fungi have been increasingly recognized as one of the most important ecological factors determining the distribution and local abundance of orchids. While some orchid species may interact with a variety of fungal associates, others are more specific in their choice of mycorrhizal partners. Moreover, orchids that co-occur at a given site, often associate with different partners, possibly to avoid competition and to allow stable coexistence. However, whether differences in mycorrhizal partners directly affect seed germination and subsequent protocorm formation remains largely unknown. In this research, we used in vitro germination experiments to investigate to what extent seed germination and protocorm formation of Gymnadenia conopsea was affected by the origin and identity of fungal associates. Fungi were isolated from G. conopsea and three other co-occurring orchid species (Dactylorhiza viridis (Coeloglossum viride), Herminium monorchis, and Platanthera chlorantha). In total, eight fungal associates, belonging to Tulasnellaceae, Ceratobasidiaceae, and Serendipitaceae, were successfully isolated and cultured. While all eight fungal strains were able to promote early germination of G. conopsea seeds, only fungal strain GS2, a member of the Ceratobasidiaceae isolated from G. conopsea itself, was able to promote protocorm formation and subsequent growth to a seedling. Two other fungal strains isolated from G. conopsea only supported seed germination until the protocorm formation stage. The other five fungal strains isolated from the co-occurring orchid species did not support seed germination beyond the protocorm stage. We conclude that, although G. conopsea is considered a mycorrhizal generalist that associates with a wide range of fungi during its adult life, it requires specific fungi to promote protocorm formation and growth to a seedling.
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Affiliation(s)
- Yue Gao
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Zeyu Zhao
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Jiayao Li
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Na Liu
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Hans Jacquemyn
- KU Leuven, Department of Biology, Plant Conservation and Population Biology, B-3001, Leuven, Belgium
| | - Shunxing Guo
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Xiaoke Xing
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China.
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Izuddin M, Srivathsan A, Lee AL, Yam TW, Webb EL. Availability of orchid mycorrhizal fungi on roadside trees in a tropical urban landscape. Sci Rep 2019; 9:19528. [PMID: 31863015 PMCID: PMC6925147 DOI: 10.1038/s41598-019-56049-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 11/24/2019] [Indexed: 12/02/2022] Open
Abstract
Urban expansion threatens biodiversity worldwide, therefore urban spaces need to be amenable to biodiversity conservation. On trees in urban environments, natural colonisation and successful translocation of epiphytic orchids are necessary to enhance urban biodiversity, and depend on the availability of compatible orchid mycorrhizal fungi (OMF). However, the extent of OMF presence and distribution, as well as niche requirements for the OMF, remain poorly studied. To identify and quantify OMF on urban trees as well as assess their suitability for native epiphytic orchids, we conducted high-throughput sequencing on tree bark and orchid root samples. OMF were detected at 60% of the study sites on 16% of 270 bark samples (from stem, fork, and branch microsites within each tree). OMF presence and richness on bark samples were related to multiple biophysical factors; in general, humus presence and precipitation levels were positively predictive of OMF presence and richness. We found Ceratobasidiaceae- and Serendipitaceae-associated OMF both on bark and within roots. Orchid species also showed differing mycorrhizal specificity. Sites associated with fungal genera Ceratobasidium, Rhizoctonia, and Serendipita were considered suitable habitats for seven orchid species. The results suggest that urban trees support OMF and are therefore suitable for native orchid species; however, OMF availability are largely constrained by biophysical factors. To maximise the likelihood of translocation success and consequent natural establishment, we propose that (micro)sites are screened for compatible OMF prior to any intervention.
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Affiliation(s)
- Muhammad Izuddin
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore.
| | - Amrita Srivathsan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Ai Lan Lee
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Tim Wing Yam
- Singapore Botanic Gardens, 1 Cluny Road, Singapore, 25956, Singapore
| | - Edward L Webb
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore.
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Oktalira FT, Whitehead MR, Linde CC. Mycorrhizal specificity in widespread and narrow-range distributed Caladenia orchid species. FUNGAL ECOL 2019. [DOI: 10.1016/j.funeco.2019.100869] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kaur J, Andrews L, Sharma J. High specificity of a rare terrestrial orchid toward a rare fungus within the North American tallgrass prairie. Fungal Biol 2019; 123:895-904. [PMID: 31733732 DOI: 10.1016/j.funbio.2019.09.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/17/2019] [Accepted: 09/24/2019] [Indexed: 10/25/2022]
Abstract
The Orchidaceae are globally distributed and represent a diverse lineage of obligate mycotrophic plants. Given their dependence on symbiotic fungi for germination and/or plant development, fungal community structure in substrates is expected to influence the distribution and persistence of orchid species. Yet, simultaneous characterization of orchid mycorrhizal fungal (OMF) communities in roots and in soil is rarely reported. To explain the co-distributions of OMF in roots, orchid-occupied, and bulk soil, we characterized mycorrhizal fungi associated with Platanthera praeclara over multiple years across its entire natural distribution within the North American tallgrass prairie. Root derived OMF communities included 24 Ceratobasidiaceae and 7 Tulasnellaceae operational taxonomic units (OTUs) though the orchid exhibited high spatio-temporal specificity toward a single Ceratobasidiaceae OTU, which was strongly stable across population sizes and phenological stages of the sampled individuals. The preferred OMF OTUs were primarily restricted to orchid-occupied locations while infrequent or absent in bulk soil. Variation in soil OMF assemblies was explained most by soil moisture, magnesium, manganese, and clay. In this first study of coupled root and soil OMF communities across a threatened grassland ecosystem, we report a strong relationship, further nuanced by soil chemistry, between a rare fungus and a rare orchid.
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Affiliation(s)
- Jaspreet Kaur
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA
| | - Lela Andrews
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Jyotsna Sharma
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79409, USA.
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Jiang J, Zhang K, Cheng S, Nie Q, Zhou SX, Chen Q, Zhou J, Zhen X, Li XT, Zhen TW, Xu M, Hsiang T, Sun Z, Zhou Y. Fusarium oxysporum KB-3 from Bletilla striata: an orchid mycorrhizal fungus. MYCORRHIZA 2019; 29:531-540. [PMID: 31270609 DOI: 10.1007/s00572-019-00904-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 06/19/2019] [Indexed: 05/20/2023]
Abstract
Orchid mycorrhizal fungi are essential for the seed germination and vegetative growth of orchids. The orchid Bletilla striata has great medical value in China because its tuber is rich in mannan. Some endophytic fungi were isolated from the roots of B. striata. The isolate KB-3 was selected for experiments because it could promote the germination of B. striata seeds. Based on morphological characters and phylogenetic analysis, the isolate KB-3 was identified as Fusarium oxysporum. Co-cultivation experiments of KB-3 with B. striata and Dendrobium candidum were performed to demonstrate orchid mycorrhizal structures. Microscopic examination showed that KB-3 established colonization and produced coiled hyphal structures known as pelotons within the cortical cells of both orchid roots. The results confirm that F. oxysporum KB-3 can behave as an orchid mycorrhizal fungus.
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Affiliation(s)
- Jianwei Jiang
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Ke Zhang
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Allmas alle 5, 75651, Uppsala, Sweden
| | - Sheng Cheng
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Qianwen Nie
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Shen-Xian Zhou
- Qingdao Agricultural University, Qingdao, 266109, Shandong, China
| | - Qingqing Chen
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Jinglong Zhou
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Xiao Zhen
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Xue Ting Li
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Tong Wen Zhen
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Mingyue Xu
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China
| | - Tom Hsiang
- Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Zhengxiang Sun
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China.
| | - Yi Zhou
- College of Agriculture, Yangtze University, Jingzhou, 434025, Hubei, China.
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Reiter N, Lawrie AC, Linde CC. Matching symbiotic associations of an endangered orchid to habitat to improve conservation outcomes. ANNALS OF BOTANY 2018; 122:947-959. [PMID: 29897399 PMCID: PMC6266109 DOI: 10.1093/aob/mcy094] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 05/13/2018] [Indexed: 05/08/2023]
Abstract
Background and Aims An understanding of mycorrhizal variation, orchid seed germination temperature and the effect of co-occurring plant species could be critical for optimizing conservation translocations of endangered plants with specialized mycorrhizal associations. Methods Focusing on the orchid Thelymitra epipactoides, we isolated mycorrhizal fungi from ten plants within each of three sites; Shallow Sands Woodland (SSW), Damp Heathland (DH) and Coastal Heathland Scrub (CHS). Twenty-seven fungal isolates were tested for symbiotic germination under three 24 h temperature cycles: 12 °C for 16 h-16 °C for 8 h, 16 °C for 16 h-24 °C for 8 h or 27 °C constant. Fungi were sequenced using the internal transcribed spacer (ITS), nuclear large subunit 1 (nLSU1), nLSU2 and mitochondrial large rRNA gene (mtLSU). Orchids were grown to maturity and co-planted with each of ten associated plant species in a glasshouse experiment with tuber width measured at 12 months after co-planting. Key Results Two Tulasnella fungal lineages were isolated and identified by phylogenetic analyses, operational taxonomic unit 1 (OTU1) and 'T. asymmetrica'. Fungal lineages were specific to sites and did not co-occur. OTU1 (from the SSW site) germinated seed predominantly at 12-16 °C (typical of autumn-winter temperature) whereas 'T. asymmetrica' (from the DH and CHS sites) germinated seed across all three temperature ranges. There was no difference in the growth of adult orchids germinated with different OTUs. There was a significant reduction in tuber size of T. epipactoides when co-planted with six of the commonly co-occurring plant species. Conclusions We found that orchid fungal lineages and their germination temperature can change with habitat, and established that translocation sites can be optimized with knowledge of co-occurring plant interactions. For conservation translocations, particularly under a changing climate, we recommend that plants should be grown with mycorrhizal fungi tailored to the recipient site.
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Affiliation(s)
- Noushka Reiter
- Royal Botanic Gardens Victoria, Cnr Ballarto Rd and Botanic Drive, Cranbourne, VIC, Australia
- Ecology and Evolution, Research School of Biology, College of Science, The Australian National University, Canberra, ACT, Australia
| | - Ann C Lawrie
- School of Science, RMIT University (Bundoora West Campus), Bundoora, VIC, Australia
| | - Celeste C Linde
- Ecology and Evolution, Research School of Biology, College of Science, The Australian National University, Canberra, ACT, Australia
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Cevallos S, Declerck S, Suárez JP. In situ Orchid Seedling-Trap Experiment Shows Few Keystone and Many Randomly Associated Mycorrhizal Fungal Species During Early Plant Colonization. FRONTIERS IN PLANT SCIENCE 2018; 9:1664. [PMID: 30505314 PMCID: PMC6250785 DOI: 10.3389/fpls.2018.01664] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 10/26/2018] [Indexed: 05/20/2023]
Abstract
Orchids are known for their vast diversity and dependency on mycorrhizal fungi. Under in situ conditions, the biotic and abiotic factors determining the composition and distribution of orchid mycorrhizal fungi (OMF) communities remain largely unexplored. Therefore in situ experiments are needed to better understand the interactions between orchids and fungi. A seedling-trap experiment was conducted in the Reserva Biológica San Francisco, a well-known biodiversity hotspot located in the Andes of southern Ecuador. The objective was to investigate the effect of orchid species, site, elevation or temporal variation on the assembly and structure of OMF associated with Cyrtochilum retusum and Epidendrum macrum. The OMF community composition was determined using the Illumina MiSeq sequencing of the internal transcribed spacer 2 (ITS2) region. The results exhibited 83 OMF operational taxonomic units belonging to Tulasnellaceae, Ceratobasidiaceae, Serendipitaceae and Atractiellales. It was observed that the composition of the OMF communities was different among orchid species and temporal variation but was not different among sites. The results further support that orchids have a core of keystone OMF that are ubiquitously distributed and stable across temporal change, whereas the majority of these fungi are randomly associated with the plants.
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Affiliation(s)
- Stefania Cevallos
- Laboratory of Mycology, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja, Loja, Ecuador
| | - Stéphane Declerck
- Laboratory of Mycology, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Juan Pablo Suárez
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja, Loja, Ecuador
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Jacquemyn H, Waud M, Brys R. Mycorrhizal divergence and selection against immigrant seeds in forest and dune populations of the partially mycoheterotrophic Pyrola rotundifolia. Mol Ecol 2018; 27:5228-5237. [PMID: 30427084 DOI: 10.1111/mec.14940] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 10/17/2018] [Accepted: 10/24/2018] [Indexed: 11/29/2022]
Abstract
Plant populations occupying different habitats may diverge from each other over time and gradually accumulate genetic and morphological differences, ultimately resulting in ecotype or even species formation. In plant species that critically rely on mycorrhizal fungi, differences in mycorrhizal communities can contribute to ecological isolation by reducing or even inhibiting germination of immigrant seeds. In this study, we investigated whether the mycorrhizal communities available in the soil and associating with the roots of seedlings and adult plants of the partially mycoheterotrophic Pyrola rotundifolia differed between populations growing in sand dunes and forests. In addition, reciprocal germination experiments were performed to test whether native seeds showed higher germination than immigrant seeds. Our results showed that the mycorrhizal communities differed significantly between forest and dune populations, and that within populations seedlings and adults also associated with different mycorrhizal communities. In both forest and dune populations, mycorrhizal communities were dominated by members of the Thelephoraceae, but dune populations showed a higher incidence of members of the Inocybaceae, whereas forest populations showed a high abundance of members of the Russulaceae. Reciprocal germination experiments showed that native seeds showed a higher germination success than immigrant seeds and this effect was most pronounced in dune populations. Overall, these results demonstrate that plants of P. rotundifolia growing in dune and forest habitats associate with different mycorrhizal communities and that reduced germination of non-native seeds may contribute to reproductive isolation. We conclude that selection against immigrants may constitute an important reproductive barrier at early stages of the speciation process.
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Affiliation(s)
- Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
| | - Michael Waud
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Leuven, Belgium
| | - Rein Brys
- Research Institute for Forest and Nature, Geraardsbergen, Belgium
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Põlme S, Bahram M, Jacquemyn H, Kennedy P, Kohout P, Moora M, Oja J, Öpik M, Pecoraro L, Tedersoo L. Host preference and network properties in biotrophic plant-fungal associations. THE NEW PHYTOLOGIST 2018; 217:1230-1239. [PMID: 29165806 DOI: 10.1111/nph.14895] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 10/13/2017] [Indexed: 05/04/2023]
Abstract
Analytical methods can offer insights into the structure of biological networks, but mechanisms that determine the structure of these networks remain unclear. We conducted a synthesis based on 111 previously published datasets to assess a range of ecological and evolutionary mechanisms that may influence the plant-associated fungal interaction networks. We calculated the relative host effect on fungal community composition and compared nestedness and modularity among different mycorrhizal types and endophytic fungal guilds. We also assessed how plant-fungal network structure was related to host phylogeny, environmental and sampling properties. Orchid mycorrhizal fungal communities responded most strongly to host identity, but the effect of host was similar among all other fungal guilds. Community nestedness, which did not differ among fungal guilds, declined significantly with increasing mean annual precipitation on a global scale. Orchid and ericoid mycorrhizal fungal communities were more modular than ectomycorrhizal and root endophytic communities, with arbuscular mycorrhizal fungi in an intermediate position. Network properties among a broad suite of plant-associated fungi were largely comparable and generally unrelated to phylogenetic distance among hosts. Instead, network metrics were predominantly affected by sampling and matrix properties, indicating the importance of study design in properly inferring ecological patterns.
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Affiliation(s)
- Sergei Põlme
- Natural History Museum, University of Tartu, 14a Ravila, 50411, Tartu, Estonia
- Department of Botany, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia
| | - Mohammad Bahram
- Department of Botany, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia
- Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 75236, Uppsala, Sweden
| | - Hans Jacquemyn
- Department of Biology, Plant Conservation and Population Biology, KU Leuven, Kasteelpark Arenberg 31, B-3001, Heverlee, Belgium
| | - Peter Kennedy
- Department of Plant Biology, University of Minnesota, 1445 Gortner Ave, St Paul, MN, 55108, USA
| | - Petr Kohout
- Department of Botany, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia
- Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43, Průhonice, Czech Republic
- Faculty of Science, Charles University, CZ-128 44, Prague 2, Czech Republic
| | - Mari Moora
- Department of Botany, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia
| | - Jane Oja
- Department of Botany, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia
| | - Maarja Öpik
- Department of Botany, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia
| | - Lorenzo Pecoraro
- Shenzhen Key Laboratory for Orchid Conservation and Utilization, The National Orchid Conservation Center of China and The Orchid Conservation and Research Center of Shenzhen, 518114, Shenzhen, China
- Center for Biotechnology & BioMedicine and Division of Life & Health Sciences, Graduate School at Shenzhen, Tsinghua University, 518055, Shenzhen, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Leho Tedersoo
- Natural History Museum, University of Tartu, 14a Ravila, 50411, Tartu, Estonia
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Jacquemyn H, Waud M, Brys R, Lallemand F, Courty PE, Robionek A, Selosse MA. Mycorrhizal Associations and Trophic Modes in Coexisting Orchids: An Ecological Continuum between Auto- and Mixotrophy. FRONTIERS IN PLANT SCIENCE 2017; 8:1497. [PMID: 28912791 PMCID: PMC5583604 DOI: 10.3389/fpls.2017.01497] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 08/14/2017] [Indexed: 05/03/2023]
Abstract
Two distinct nutritional syndromes have been described in temperate green orchids. Most orchids form mycorrhizas with rhizoctonia fungi and are considered autotrophic. Some orchids, however, associate with fungi that simultaneously form ectomycorrhizas with surrounding trees and derive their carbon from these fungi. This evolutionarily derived condition has been called mixotrophy or partial mycoheterotrophy and is characterized by 13C enrichment and high N content. Although it has been suggested that the two major nutritional syndromes are clearly distinct and tightly linked to the composition of mycorrhizal communities, recent studies have challenged this assumption. Here, we investigated whether mycorrhizal communities and nutritional syndromes differed between seven green orchid species that co-occur under similar ecological conditions (coastal dune slacks). Our results showed that mycorrhizal communities differed significantly between orchid species. Rhizoctonia fungi dominated in Dactylorhiza sp., Herminium monorchis, and Epipactis palustris, which were autotrophic based on 13C and N content. Conversely, Liparis loeselii and Epipactis neerlandica associated primarily with ectomycorrhizal fungi but surprisingly, 13C and N content supported mixotrophy only in E. neerlandica. This, together with the finding of some ectomycorrhizal fungi in rhizoctonia-associated orchids, suggests that there exists an ecological continuum between the two syndromes. The presence of a large number of indicator species associating with individual orchid species further confirms previous findings that mycorrhizal fungi may be important factors driving niche-partitioning in terrestrial orchids and therefore contribute to orchid coexistence.
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Affiliation(s)
- Hans Jacquemyn
- Plant Conservation and Population Biology, Department of Biology, KU LeuvenLeuven, Belgium
| | - Michael Waud
- Plant Conservation and Population Biology, Department of Biology, KU LeuvenLeuven, Belgium
| | - Rein Brys
- Research Institute for Forest and NatureGeraardsbergen, Belgium
| | - Félix Lallemand
- Institut de Systématique, Évolution, Biodiversité, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum National d’Histoire Naturelle, Sorbonne UniversitésParis, France
| | | | - Alicja Robionek
- The Laboratory of Freshwater Ecology, Department of Plant Ecology, University of GdańskGdańsk, Poland
- Department of Plant Taxonomy and Nature Conservation, University of GdańskGdańsk, Poland
| | - Marc-André Selosse
- Institut de Systématique, Évolution, Biodiversité, UMR 7205, CNRS, MNHN, UPMC, EPHE, Muséum National d’Histoire Naturelle, Sorbonne UniversitésParis, France
- Department of Plant Taxonomy and Nature Conservation, University of GdańskGdańsk, Poland
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