1
|
Hartvig I, Kosawang C, Rasmussen H, Kjær ED, Nielsen LR. Co-occurring orchid species associated with different low-abundance mycorrhizal fungi from the soil in a high-diversity conservation area in Denmark. Ecol Evol 2024; 14:e10863. [PMID: 38304271 PMCID: PMC10828919 DOI: 10.1002/ece3.10863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/09/2024] [Accepted: 01/14/2024] [Indexed: 02/03/2024] Open
Abstract
Plant-fungal interactions are ubiquitous across ecosystems and contribute significantly to plant ecology and evolution. All orchids form obligate symbiotic relationships with specific fungi for germination and early growth, and the distribution of terrestrial orchid species has been linked to occurrence and abundance of specific orchid mycorrhizal fungi (OMF) in the soil. The availability of OMF can therefore be a habitat requirement that is relevant to consider when establishing management and conservation strategies for threatened orchid species, but knowledge on the spatial distribution of OMF in soil is limited. We here studied the mycorrhizal associations of three terrestrial orchid species (Anacamptis pyramidalis, Orchis purpurea and Platanthera chlorantha) found in a local orchid diversity hotspot in eastern Denmark, and investigated the abundance of the identified mycorrhizal fungi in the surrounding soil. We applied ITS metabarcoding to samples of orchid roots, rhizosphere soil and bulk soil collected at three localities, supplemented with standard barcoding of root samples with OMF specific primers, and detected 22 Operational Taxonomic Units (OTUs) putatively identified as OMF. The three orchid species displayed different patterns of OMF associations, supporting the theory that association with specific fungi constitutes part of an orchid's ecological niche allowing co-occurrence of many species in orchid-rich habitats. The identified mycorrhizal partners in the basidiomycete families Tulasnellaceae and Ceratobasidiaceae (Cantharallales) were detected in low abundance in rhizosphere soil, and appeared almost absent from bulk soil at the localities. This finding highlights our limited knowledge of the ecology and trophic mode of OMF outside orchid tissues, as well as challenges in the detection of specific OMF with standard methods. Potential implications for management and conservation strategies are discussed.
Collapse
Affiliation(s)
- Ida Hartvig
- Forest and Landscape Ecology, Department of Geosciences and Natural Resource ManagementUniversity of CopenhagenCopenhagenDenmark
- Center for Evolutionary Hologenomics, Globe InstituteUniversity of CopenhagenCopenhagenDenmark
- Smithsonian Environmental Research CenterSmithsonian InstituteEdgewaterMarylandUSA
| | - Chatchai Kosawang
- Forest and Landscape Ecology, Department of Geosciences and Natural Resource ManagementUniversity of CopenhagenCopenhagenDenmark
| | - Hanne Rasmussen
- Forest and Landscape Ecology, Department of Geosciences and Natural Resource ManagementUniversity of CopenhagenCopenhagenDenmark
| | - Erik Dahl Kjær
- Forest and Landscape Ecology, Department of Geosciences and Natural Resource ManagementUniversity of CopenhagenCopenhagenDenmark
| | - Lene Rostgaard Nielsen
- Forest and Landscape Ecology, Department of Geosciences and Natural Resource ManagementUniversity of CopenhagenCopenhagenDenmark
| |
Collapse
|
2
|
Dove A, Charters MD, Campbell MJ, Blake H, Menon M, Sarasan V. Fungal Community Composition at the Last Remaining Wild Site of Yellow Early Marsh Orchid ( Dactylorhiza incarnata ssp. ochroleuca). Microorganisms 2023; 11:2124. [PMID: 37630684 PMCID: PMC10459220 DOI: 10.3390/microorganisms11082124] [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: 07/05/2023] [Revised: 08/01/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
The yellow early marsh orchid (Dactylorhiza incarnata ssp. ochroleuca) is a critically endangered terrestrial orchid in Britain. Previous attempts to translocate symbiotic seedlings to a site near the last remaining wild site demonstrated some success, with a 10% survival rate despite adverse weather conditions over a two-year period. However, to facilitate future reintroduction efforts or conservation translocations, a more comprehensive understanding of the fungal microbiome and abiotic soil characteristics at the final remaining wild site is required. Obtaining comprehensive information on both the fungal community and soil nutrient composition from wild sites has significant benefits and may prove critical for the success of future conservation translocations involving threatened orchids. This preliminary study, conducted at the last remaining wild site, revealed a significant correlation between the relative abundance of the orchid mycorrhizal fungal order Cantharellales and the concentrations of nitrate and phosphate in the soil. Another orchid mycorrhizal fungal group, Sebacinales, was found to be distributed extensively throughout the site. The composition of fungal communities across the entire site, orchid-hosting and non-orchid-hosting soils is discussed in relation to reinforcing the current population and preventing the extinction of this orchid.
Collapse
Affiliation(s)
- Andrea Dove
- Royal Botanic Gardens, Kew, Richmond TW9 3DS, UK
| | | | | | - Hanna Blake
- Department of Geography, University of Sheffield, Sheffield S10 2TN, UK; (H.B.)
| | - Manoj Menon
- Department of Geography, University of Sheffield, Sheffield S10 2TN, UK; (H.B.)
| | | |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Kaur J, Harder CB, Sharma J. Congeneric temperate orchids recruit similar-yet differentially abundant-endophytic bacterial communities that are uncoupled from soil, but linked to host phenology and population size. AMERICAN JOURNAL OF BOTANY 2023; 110:e16168. [PMID: 37052191 DOI: 10.1002/ajb2.16168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 03/20/2023] [Accepted: 03/20/2023] [Indexed: 05/16/2023]
Abstract
PREMISE Besides the beneficial plant-fungus symbiosis in mycorrhizal plants, bacteria also enhance plant fitness via tripartite interactions. While bacterial associations are presumably just as important for the obligate mycorrhizal family Orchidaceae, little is known about orchid associating bacteria (OAB). METHODS We examined the OAB communities of two, congeneric, terrestrial orchids, Platanthera cooperi and Platanthera praeclara, which represent widely disparate North American ecosystems. We tested whether they recruit distinct OAB communities, and whether variability in OAB communities can be linked to phenology, population size, or habitat soil. Genomic DNAs from roots of seedling, vegetative, and reproductive plants and from soil were subjected to Illumina sequencing of V4 and V5 regions of the 16S rRNA gene. RESULTS We obtained 809 OAB Zero-radius Operational Taxonomic Units (ZOTUs). Despite an overlap of 209 ZOTUs that accounted for >75% relative abundances of their respective OAB communities, the overall community structures of the two orchids were distinct. Within each orchid, distinctions were detected in the OAB communities of large and small populations and the three phenological stages. The OAB ZOTUs were either absent or present with low abundances in soil associated with both orchids. CONCLUSIONS The two orchids exhibited preferential recruitment of known growth-promoting OAB communities from soil. Their OAB communities also showed considerable overlap despite the large environmental and geographical separation of the two host taxa. Our results lend further support to the emerging evidence that not only the fungi, but root-associated bacteria also have functional importance for orchid ecology.
Collapse
Affiliation(s)
- Jaspreet Kaur
- Department of Plant and Soil Science, Texas Tech University, Lubbock, Texas, USA
- Department of Biology, University of Wisconsin-La Crosse, La Crosse, Wisconsin, USA
| | - Christoffer B Harder
- Department of Plant and Soil Science, Texas Tech University, Lubbock, Texas, USA
- Department of Biology, MEMEG, Lund University, Ekologihuset, Sölvegatan, Sweden
- Department of Biology, Section of Terrestrial Ecology, University of Copenhagen, Copenhagen, Denmark
| | - Jyotsna Sharma
- Department of Plant and Soil Science, Texas Tech University, Lubbock, Texas, USA
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Factors in the Distribution of Mycorrhizal and Soil Fungi. DIVERSITY 2022. [DOI: 10.3390/d14121122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Soil fungi are crucial microorganisms in the functioning of ecosystems. They shape the soil properties, facilitate nutrient circulation, and assist with plant growth. However, their biogeography and distribution studies are limited compared to other groups of organisms. This review aims to provide an overview of the main factors shaping the spatial distribution of soil fungi (with a special focus on mycorrhizal fungi). The review also tries to identify the field frontier where further studies are needed. The main drivers of soil fungal distribution were classified and reviewed into three groups: soil properties, plant interactions, and dispersal vectors. It was apparent that ectomycorrhizal and arbuscular fungi are relatively overrepresented in the body of research, while the other mycorrhiza types and endophytes were grossly omitted. Notwithstanding, soil pH and the share of ectomycorrhizal plants in the plant coverage were repeatedly reported as strong predictors of mycorrhizal fungal distribution. Dispersal potential and vector preferences show more variation among fungi, especially when considering long-distance dispersal. Additionally, special attention was given to the applications of the island biogeography theory to soil fungal assemblages. This theory proves to be a very efficient framework for analyzing and understanding not only the soil fungal communities of real islands but even more effective islands, i.e., isolated habitats, such as patches of trees discontinuous from more enormous forests.
Collapse
|
9
|
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.
Collapse
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:
| |
Collapse
|
10
|
Wang T, Wang X, Gang Y, Cui X, Lan H, Liu Z. Spatial Pattern of Endophytic Fungi and the Symbiotic Germination of Tulasnella Fungi from Wild Cymbidium goeringii (Orchidaceae) in China. Curr Microbiol 2022; 79:139. [PMID: 35305159 DOI: 10.1007/s00284-022-02826-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 12/17/2021] [Indexed: 11/03/2022]
Abstract
The endophytic microbiome in orchid plants is rich and diverse; however, few studies have analyzed the endophytic microbiome of Cymbidium plants in different tissues and soils. This study implemented the Illumina Miseq technology to investigate the diversity of endophytic fungi in different tissues of wild Cymbidium goeringii. The results demonstrated that different tissue samples harbor a rich fungal endophytic community, and those fungi could be classified into 4 phyla, at least 145 families, and 185 genera. The endophytic fungal community diversity differed among the orchid tissues and soils, and some fungal taxa were clearly concentrated in certain orchid tissues, with more operational taxonomic units (OTUs) being detected. Investigation of mycorrhizal associations showed that 43 (about 3.8%) of the total 1137 OTUs could be assigned as Orchidaceae mycorrhizal fungi (OMF), while about 96.2% the OTUs were non-mycorrhizal fungi. Among the OMFs, OTUs of the ectomycorrhizal fungi Russulaceae and Thelephoraceae families were the most abundant, with different richness in the soil, followed by Tulasnellaceae and Ceratobasidiaceae, which were dominant in the root communities of C. goeringii. In the seeds, the absolutely dominant family was Nectriaceae, and the common OMFs Ceratobasidiaceae (five OTUs) and Tulasnellaceae (one OTU) were also detected in the seeds. Two Tulasnella spp. isolates from the roots of wild C. goeringii could effectively promote seed germination and rhizome formation of wild C. goeringii, and these strains might be particularly important in the practice of conservation for many endangered C. goeringii in China.
Collapse
Affiliation(s)
- Tao Wang
- Beijing Botanical Garden, Beijing Floriculture Engineering Technology Research Centre, Beijing Laboratory of Urban and Rural Ecological Environment, Beijing, 100093, China
| | - Xiaojing Wang
- State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China
| | - Yanqing Gang
- Hainan Jiachai Investment Holding Development Co., Ltd, Haikou, 572925, China
| | - Xia Cui
- Beijing Botanical Garden, Beijing Floriculture Engineering Technology Research Centre, Beijing Laboratory of Urban and Rural Ecological Environment, Beijing, 100093, China
| | - Huiwen Lan
- Hainan Jiachai Investment Holding Development Co., Ltd, Haikou, 572925, China
| | - Zhenhua Liu
- Hunan Academy of Forestry Sciences, Changsha, 410004, China.
| |
Collapse
|
11
|
Weerasuriya NM, Kukolj K, Spencer R, Sveshnikov D, Thorn RG. Multiple Fungi May Connect the Roots of an Orchid ( Cypripedium reginae) and Ash ( Fraxinus nigra) in Western Newfoundland. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:805127. [PMID: 37746191 PMCID: PMC10512338 DOI: 10.3389/ffunb.2022.805127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/07/2022] [Indexed: 09/26/2023]
Abstract
Showy lady's slipper (Cypripedium reginae Walter, Orchidaceae) and black ash (Fraxinus nigra Marshall, Oleaceae) often co-occur in close proximity in fens in western Newfoundland, Canada. Metabarcoding of DNA extracted from root samples of both species following surface sterilization, and others without surface sterilization was used to determine if there were shared fungal endophytes in the roots of both species that could form a common mycorrhizal network between them. A wide variety of fungi were recovered from primers amplifying the nuclear ribosomal internal transcribed spacer region (ITS2). Sixty-six fungal sequences were shared by surface-sterilized roots of both orchid and ash, among them arbuscular mycorrhizal fungi (Claroideoglomus, Dominikia, Glomus and Rhizophagus), ectomycorrhizal fungi (Inocybe and Tomentella), the broad-host root endophyte Cadophora orchidicola, along with root pathogens (Dactylonectria, Ilyonectria, Pyricularia, and Xylomyces) and fungi of unknown function. There appear to be multiple fungi that could form a common mycorrhizal network between C. reginae and F. nigra, which might explain their frequent co-occurrence. Transfer of nutrients or carbon between the orchid and ash via one or more of the shared fungal endophytes remains to be demonstrated.
Collapse
Affiliation(s)
| | - Katarina Kukolj
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Rebecca Spencer
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Dmitry Sveshnikov
- School of Science and the Environment, Grenfell Campus, Memorial University, Corner Brook, NL, Canada
| | - R. Greg Thorn
- Department of Biology, University of Western Ontario, London, ON, Canada
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Cook K, Sharma J, Taylor AD, Herriott IC, Taylor DL. Epiphytic fungal communities vary by substrate type and at sub-meter spatial scales. Mol Ecol 2022; 31:1879-1891. [PMID: 35060231 DOI: 10.1111/mec.16358] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/17/2021] [Accepted: 01/07/2022] [Indexed: 11/30/2022]
Abstract
Fungal species have numerous important environmental functions. Where these functions occur will depend on how fungi are spatially distributed, but spatial structures of fungal communities are largely unknown, especially in understudied hyperdiverse tropical tree canopy systems. We explore fungal communities in a Costa Rican tropical rainforest canopy, with a focus on local-scale spatial structure and substrate specificity of fungi. Samples of ~1 cm3 were collected from 135 points along 5 adjacent tree branches, with inter-sample distances from 1 to 800 cm, and dissected into four substrates: outer host tree bark, inner bark, dead bryophytes, and living bryophytes. We sequenced the ITS2 region to characterize total fungal communities. Fungal community composition and diversity varied among substrate types, even when multiple substrates were in direct contact. Fungi were most diverse in living bryophytes, with 39% of all OTUs found exclusively in this substrate, and the least diverse in inner bark. Fungal communities had significant positive spatial autocorrelation and distance decay of similarity only at distances less than one meter. Similarity among samples declines by half in less than ten cm, and even at these short distances, similarities are low with few OTUs shared among samples. These results indicate that community turnover is high and occurs at very small spatial scales, with any two locations sharing very few fungi in common. High heterogeneity of fungal communities in space and among substrates may have implications for the distributions, population dynamics, and diversity of other tree canopy organisms, including epiphytic plants.
Collapse
Affiliation(s)
- Kel Cook
- Department of Biology, University of New Mexico, Castetter Hall 1480, MSC03-2020, 219 Yale Blvd NE, Albuquerque, NM, 87131-0001, USA
| | - Jyotsna Sharma
- Department of Plant and Soil Science, Texas Tech University, Bayer Plant Science Building, Room 219, 2911 15th Street, Mail Stop 2122, Lubbock, TX, 79409-2122, USA
| | - Andrew D Taylor
- Department of Biology, University of Hawai'i at Manoa, 2538 McCarthy Mall, Edmondson Hall 216, Honolulu, HI, 96822, USA
| | - Ian Charold Herriott
- Institute of Arctic Biology, University of Alaska, 311 Irving I Building, Fairbanks, AK, 99775, USA
| | - D Lee Taylor
- Department of Biology, University of New Mexico, Castetter Hall 1480, MSC03-2020, 219 Yale Blvd NE, Albuquerque, NM, 87131-0001, USA
| |
Collapse
|
14
|
Mycorrhizal Fungal Partners Remain Constant during a Root Lifecycle of Pleione bulbocodioides (Orchidaceae). J Fungi (Basel) 2021; 7:jof7110994. [PMID: 34829281 PMCID: PMC8621020 DOI: 10.3390/jof7110994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/04/2021] [Accepted: 11/17/2021] [Indexed: 11/17/2022] Open
Abstract
Mycorrhizal mutualisms are vital for orchids through germination to adulthood. Fungal species diversity and community composition vary across seasons and plant development stages and affect plant survival, adaptation, and community maintenance. Knowledge of the temporal turnover of mycorrhizal fungi (OMF) remains poorly understood in the eco-physiologically diverse orchids (especially in epiphytic orchids), although it is important to understand the function and adaptation of mycorrhizae. Some species of Pleione are epiphytic plants with annual roots and may recruit different fungal partners during their root lifecycle. Based on continuous samplings of Pleione bulbocodioides during a whole root lifecycle, we characterized the fungal temporal dynamics using Illumina sequencing of the ITS2 region. Our data showed that the plants of P. bulbocodioides were quickly colonized by OMF at root emergence and had a constant OMF composition throughout one root lifecycle, although the OMF richness declined with root aging after a peak occurrence during root elongation. In contrast, the richness of root-inhabiting fungal endophytes kept increasing with root aging and more drastic turnovers were found in their species compositions. Our findings of OMF temporal turnover contribute to further understanding of mycorrhizal associations and adaptation of Orchidaceae and will benefit orchid resource conservation and utilization.
Collapse
|
15
|
|
16
|
Petrolli R, Augusto Vieira C, Jakalski M, Bocayuva MF, Vallé C, Cruz EDS, Selosse MA, Martos F, Kasuya MCM. A fine-scale spatial analysis of fungal communities on tropical tree bark unveils the epiphytic rhizosphere in orchids. THE NEW PHYTOLOGIST 2021; 231:2002-2014. [PMID: 33983644 DOI: 10.1111/nph.17459] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/04/2021] [Indexed: 05/27/2023]
Abstract
Approximately 10% of vascular plants are epiphytes and, even though this has long been ignored in past research, are able to interact with a variety of fungi, including mycorrhizal taxa. However, the structure of fungal communities on bark, as well as their relationship with epiphytic plants, is largely unknown. To fill this gap, we conducted environmental metabarcoding of the ITS-2 region to understand the spatial structure of fungal communities of the bark of tropical trees, with a focus on epiphytic orchid mycorrhizal fungi, and tested the influence of root proximity. For all guilds, including orchid mycorrhizal fungi, fungal communities were more similar when spatially close on bark (i.e. they displayed positive spatial autocorrelation). They also showed distance decay of similarity with respect to epiphytic roots, meaning that their composition on bark increasingly differed, compared to roots, with distance from roots. We first showed that all of the investigated fungal guilds exhibited spatial structure at very small scales. This spatial structure was influenced by the roots of epiphytic plants, suggesting the existence of an epiphytic rhizosphere. Finally, we showed that orchid mycorrhizal fungi were aggregated around them, possibly as a result of reciprocal influence between the mycorrhizal partners.
Collapse
Affiliation(s)
- Rémi Petrolli
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, EPHE, Sorbonne Université, CP 39, 57 rue Cuvier, Paris, F-75005, France
| | - Conrado Augusto Vieira
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, EPHE, Sorbonne Université, CP 39, 57 rue Cuvier, Paris, F-75005, France
- Department of Microbiology, Viçosa Federal University (UFV), P. H. Rolfs Street CEP: 36570-900, Viçosa, Minas Gerais, Brazil
| | - Marcin Jakalski
- Faculty of Biology, University of Gdańsk, ul. Wita Stwosza 59, Gdańsk, 80-308, Poland
| | - Melissa F Bocayuva
- Department of Microbiology, Viçosa Federal University (UFV), P. H. Rolfs Street CEP: 36570-900, Viçosa, Minas Gerais, Brazil
| | - Clément Vallé
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, EPHE, Sorbonne Université, CP 39, 57 rue Cuvier, Paris, F-75005, France
| | - Everaldo Da Silva Cruz
- Department of Microbiology, Viçosa Federal University (UFV), P. H. Rolfs Street CEP: 36570-900, Viçosa, Minas Gerais, Brazil
| | - Marc-André Selosse
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, EPHE, Sorbonne Université, CP 39, 57 rue Cuvier, Paris, F-75005, France
- Department of Microbiology, Viçosa Federal University (UFV), P. H. Rolfs Street CEP: 36570-900, Viçosa, Minas Gerais, Brazil
- Faculty of Biology, University of Gdańsk, ul. Wita Stwosza 59, Gdańsk, 80-308, Poland
| | - Florent Martos
- Institut de Systématique, Évolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, EPHE, Sorbonne Université, CP 39, 57 rue Cuvier, Paris, F-75005, France
| | - Maria Catarina M Kasuya
- Department of Microbiology, Viçosa Federal University (UFV), P. H. Rolfs Street CEP: 36570-900, Viçosa, Minas Gerais, Brazil
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Metabarcoding on both environmental DNA and RNA highlights differences between fungal communities sampled in different habitats. PLoS One 2020; 15:e0244682. [PMID: 33378355 PMCID: PMC7773206 DOI: 10.1371/journal.pone.0244682] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 12/14/2020] [Indexed: 12/14/2022] Open
Abstract
In recent years, metabarcoding has become a key tool to describe microbial communities from natural and artificial environments. Thanks to its high throughput nature, metabarcoding efficiently explores microbial biodiversity under different conditions. It can be performed on environmental (e)DNA to describe so-called total microbial community, or from environmental (e)RNA to describe active microbial community. As opposed to total microbial communities, active ones exclude dead or dormant organisms. For what concerns Fungi, which are mostly filamentous microorganisms, the relationship between DNA-based (total) and RNA-based (active) communities is unclear. In the present study, we evaluated the consequences of performing metabarcoding on both soil and wood-extracted eDNA and eRNA to delineate molecular operational taxonomic units (MOTUs) and differentiate fungal communities according to the environment they originate from. DNA and RNA-based communities differed not only in their taxonomic composition, but also in the relative abundances of several functional guilds. From a taxonomic perspective, we showed that several higher taxa are globally more represented in either “active” or “total” microbial communities. We also observed that delineation of MOTUs based on their co-occurrence among DNA and RNA sequences highlighted differences between the studied habitats that were overlooked when all MOTUs were considered, including those identified exclusively by eDNA sequences. We conclude that metabarcoding on eRNA provides original functional information on the specific roles of several taxonomic or functional groups that would not have been revealed using eDNA alone.
Collapse
|
21
|
Vogt-Schilb H, Těšitelová T, Kotilínek M, Sucháček P, Kohout P, Jersáková J. Altered rhizoctonia assemblages in grasslands on ex-arable land support germination of mycorrhizal generalist, not specialist orchids. THE NEW PHYTOLOGIST 2020; 227:1200-1212. [PMID: 32285948 DOI: 10.1111/nph.16604] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 04/01/2020] [Indexed: 05/03/2023]
Abstract
Species-rich seminatural grasslands in Central Europe have suffered a dramatic loss of biodiversity due to conversion to arable land, but vast areas are being restored. Population recovery of orchids, which depend on mycorrhizal fungi for germination, is however limited. We hypothesised that ploughing and fertilisation caused shifts in orchid mycorrhizal communities in soil and restricted orchid germination. We examined edaphic conditions in 60 restored and seminatural grasslands, and germination success in 10 restored grasslands. Using a newly designed primer, we screened the composition of rhizoctonias in soil, seedlings and roots of seven orchid species. Seminatural and restored grasslands differed significantly in nutrient amounts and rhizoctonia assemblages in soil. While Serendipitaceae prevailed in seminatural grasslands with a higher organic matter content, Ceratobasidiaceae were more frequent in phosphorus-rich restored grasslands with increased abundance on younger restored sites. Tulasnellaceae displayed no preference. Germination success in restored grasslands differed significantly between orchid species; two mycorrhizal generalist species germinated with a broad range of rhizoctonias at most restored grasslands, while germination success of specialists was low. Past agricultural practices have a long-lasting effect on soil conditions and orchid mycorrhizal communities. Altered mycorrhizal availability may be the main reason for low germination success of specialist orchid species.
Collapse
Affiliation(s)
- Hélène Vogt-Schilb
- Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic
- CEFE, CNRS, EPHE, IRD, Université de Montpellier, Université Paul-Valéry Montpellier, 1919 Route de Mende, 34293, Montpellier, France
| | - Tamara Těšitelová
- Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic
| | - Milan Kotilínek
- Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic
| | - Pavel Sucháček
- Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic
| | - Petr Kohout
- Institute of Microbiology ASCR, Vídeňská 1083, 142 20, Prague 4 - Krč, Czech Republic
- Faculty of Science, Charles University, CZ-128 44, Prague 2, Czech Republic
| | - Jana Jersáková
- Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic
| |
Collapse
|
22
|
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.
Collapse
|
23
|
Lin M, Xiong H, Xiang X, Zhou Z, Liang L, Mei Z. The Effect of Plant Geographical Location and Developmental Stage on Root-Associated Microbiomes of Gymnadenia conopsea. Front Microbiol 2020; 11:1257. [PMID: 32625183 PMCID: PMC7314937 DOI: 10.3389/fmicb.2020.01257] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/18/2020] [Indexed: 12/26/2022] Open
Abstract
Gymnadenia conopsea (L.) R. Br. is an important perennial terrestrial photosynthetic orchid species whose microbiomes are considered to play an important role in helping its germination and growth. However, the assemblage of G. conopsea root-associated microbial communities is poorly understood. The compositions of fungal and bacterial communities from the roots and corresponding soil samples in G. conopsea across distinct biogeographical regions from two significantly different altitudes were characterized at the vegetative and reproductive growth stages. The geographical location, developmental stage and compartment were factors contributing to microbiome variation in G. conopsea. Predominant fungal taxa include Ascomycota, Basidiomycota, Mortierellomycota and Chytridiomycota, whereas Proteobacteria, Bacteroidetes, Acidobacteria, Actinobacteria, Verrucomicrobia, Chloroflexi, TM7 and Planctomycetes were predominant bacterial taxa. Using G. conopsea as a model, the structural and functional composition in G. conopsea root-associated microbiomes were comprehensive analyzed. Contrary to previous studies, biogeography was the main factor influencing the microbial community in this study. Besides, compartment and developmental stage should also be considered to analyze the variation of microbiota composition. Although the microbial composition varied greatly by location, the symbiotic microorganisms of G. conopsea still have certain specificity. This study gives an abundant information of G. conopsea root-associated microbiomes and provides new clues to better understanding the factors affecting the composition and diversity of fungal/bacterial communities associated with orchids. Our results also laying a foundation for harnessing the microbiome for sustainable G. conopsea cultivation. Moreover, these results might be generally applicable to other orchidaceae plants.
Collapse
Affiliation(s)
- Min Lin
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Hui Xiong
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Xuechuan Xiang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Zelin Zhou
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| | - Lifeng Liang
- Institute of Ethnomedicine, South-Central University for Nationalities, Wuhan, China
| | - Zhinan Mei
- School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan, China
| |
Collapse
|
24
|
Aas AB, Andrew CJ, Blaalid R, Vik U, Kauserud H, Davey ML. Fine-scale diversity patterns in belowground microbial communities are consistent across kingdoms. FEMS Microbiol Ecol 2020; 95:5484836. [PMID: 31049552 DOI: 10.1093/femsec/fiz058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 04/30/2019] [Indexed: 11/12/2022] Open
Abstract
The belowground environment is heterogeneous and complex at fine spatial scales. Physical structures, biotic components and abiotic conditions create a patchwork mosaic of potential niches for microbes. Questions remain about mechanisms and patterns of community assembly belowground, including: Do fungal and bacterial communities assemble differently? How do microbes reach the roots of host plants? Within a 4 m2 plot in alpine vegetation, high throughput sequencing of the 16S (bacteria) and ITS1 (fungal) ribosomal RNA genes was used to characterise microbial community composition in roots and adjacent soil of a viviparous host plant (Bistorta vivipara). At fine spatial scales, beta-diversity patterns in belowground bacterial and fungal communities were consistent, although compositional change was greater in bacteria than fungi. Spatial structure and distance-decay relationships were also similar for bacteria and fungi, with significant spatial structure detected at <50 cm among root- but not soil-associated microbes. Recruitment of root microbes from the soil community appeared limited at this sampling and sequencing depth. Possible explanations for this include recruitment from low-abundance populations of soil microbes, active recruitment from neighbouring plants and/or vertical transmission of symbionts to new clones, suggesting varied methods of microbial community assembly for viviparous plants. Our results suggest that even at relatively small spatial scales, deterministic processes play a significant role in belowground microbial community structure and assembly.
Collapse
Affiliation(s)
- Anders Bjørnsgaard Aas
- Section of Genetic and Evolution Department of Biosciences, University of Oslo, Oslo, Norway
| | - Carrie J Andrew
- Section of Genetic and Evolution Department of Biosciences, University of Oslo, Oslo, Norway
| | - Rakel Blaalid
- Norwegian Institute for Nature Research, Bergen, Norway
| | - Unni Vik
- Section of Genetic and Evolution Department of Biosciences, University of Oslo, Oslo, Norway
| | - Håvard Kauserud
- Section of Genetic and Evolution Department of Biosciences, University of Oslo, Oslo, Norway
| | - Marie L Davey
- Section of Genetic and Evolution Department of Biosciences, University of Oslo, Oslo, Norway.,Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research, NO-1431 Ås, Norway
| |
Collapse
|
25
|
Adamo M, Chialva M, Calevo J, De Rose S, Girlanda M, Perotto S, Balestrini R. The Dark Side of Orchid Symbiosis: Can Tulasnella calospora Decompose Host Tissues? Int J Mol Sci 2020; 21:E3139. [PMID: 32365577 PMCID: PMC7247694 DOI: 10.3390/ijms21093139] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 01/02/2023] Open
Abstract
Photosynthetic orchids associate with mycorrhizal fungi that can be mostly ascribed to the "rhizoctonia" species complex. Rhizoctonias' phylogenetic diversity covers a variety of ecological/nutritional strategies that include, beside the symbiosis establishment with host plants, endophytic and pathogenic associations with non-orchid plants or saprotrophic soil colonization. In addition, orchid mycorrhizal fungi (OMF) that establish a symbiotic relationship with an orchid host can later proliferate in browning and rotting orchid tissues. Environmental triggers and molecular mechanisms governing the switch leading to either a saprotrophic or a mycorrhizal behavior in OMF remain unclear. As the sequenced OMF genomes feature a wide range of genes putatively involved in the degradation of plant cell wall (PCW) components, we tested if these transitions may be correlated with a change in the expression of some PCW degrading enzymes. Regulation of several genes encoding PCW degrading enzymes was evaluated during saprotrophic growth of the OMF Tulasnella calospora on different substrates and under successful and unsuccessful mycorrhizal symbioses. Fungal gene expression in planta was investigated in two orchid species, the terrestrial Mediterranean Serapias vomeracea and the epiphytic tropical Cattleya purpurata. Although we only tested a subset of the CAZyme genes identified in the T. calospora genome, and we cannot exclude therefore a role for different CAZyme families or members inside a family, the results showed that the degradative potential of T. calospora is finely regulated during saprotrophic growth and in symbiosis, often with a different regulation in the two orchid species. These data pose novel questions about the role of fungal PCW degrading enzymes in the development of unsuccessful and successful interactions.
Collapse
Affiliation(s)
- Martino Adamo
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy; (M.A.); (M.C.); (S.D.R.); (M.G.); (S.P.)
| | - Matteo Chialva
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy; (M.A.); (M.C.); (S.D.R.); (M.G.); (S.P.)
| | - Jacopo Calevo
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy; (M.A.); (M.C.); (S.D.R.); (M.G.); (S.P.)
| | - Silvia De Rose
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy; (M.A.); (M.C.); (S.D.R.); (M.G.); (S.P.)
| | - Mariangela Girlanda
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy; (M.A.); (M.C.); (S.D.R.); (M.G.); (S.P.)
| | - Silvia Perotto
- Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy; (M.A.); (M.C.); (S.D.R.); (M.G.); (S.P.)
| | - Raffaella Balestrini
- National Research Council, Institute for Sustainable Plant Protection, Viale Mattioli 25, 10125 Turin, Italy
| |
Collapse
|
26
|
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.
Collapse
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.
| |
Collapse
|
27
|
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.
Collapse
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.
| |
Collapse
|
28
|
Zhang J, Zhang B, Liu Y, Guo Y, Shi P, Wei G. Distinct large-scale biogeographic patterns of fungal communities in bulk soil and soybean rhizosphere in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:791-800. [PMID: 29990927 DOI: 10.1016/j.scitotenv.2018.07.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 06/27/2018] [Accepted: 07/01/2018] [Indexed: 05/20/2023]
Abstract
Fungi play a crucial role in the agroecological system; however, little is known about their large-scale biogeographical patterns and how various ecological processes contribute to community assembly, especially in the crop rhizosphere. In this study, we investigated the spatial distribution and community assembly of fungi in the bulk soil and rhizosphere of soybean collected from 43 sites across China using high-throughput sequencing. The alpha diversity of the rhizosphere was lower than that of bulk soil. The fungal community structures of the two soil compartments were distinct. Fungal communities in the rhizosphere had a steeper distance-decay relationship slope between sampled sites than those in bulk soil, suggesting a greater influence of historical processes (geographical separation) in the rhizosphere. The relative importance of dispersal limitation and environmental filtering for the fungal community composition differed between bulk soil and rhizosphere. Sloan neutral model analysis suggested that niche-based processes dominated the assemblage of fungal communities in the two soil compartments, while neutral processes had a weaker influence in the rhizosphere than in bulk soil. Additionally, we analyzed the structures of abundant and rare fungal sub-communities in each soil compartment. Rare sub-communities were more strongly influenced by dispersal limitation than abundant sub-communities. These results expand the current understanding of root-associated fungal community biogeography in agricultural soils on a large scale.
Collapse
Affiliation(s)
- Jun Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Baogang Zhang
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Yao Liu
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Yanqing Guo
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Peng Shi
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Gehong Wei
- State Key Laboratory of Crop Stress Biology in Arid Areas, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
| |
Collapse
|
29
|
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.
Collapse
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
| |
Collapse
|
30
|
Spini G, Spina F, Poli A, Blieux AL, Regnier T, Gramellini C, Varese GC, Puglisi E. Molecular and Microbiological Insights on the Enrichment Procedures for the Isolation of Petroleum Degrading Bacteria and Fungi. Front Microbiol 2018; 9:2543. [PMID: 30425689 PMCID: PMC6218658 DOI: 10.3389/fmicb.2018.02543] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/05/2018] [Indexed: 12/15/2022] Open
Abstract
Autochthonous bioaugmentation, by exploiting the indigenous microorganisms of the contaminated environment to be treated, can represent a successful bioremediation strategy. In this perspective, we have assessed by molecular methods the evolution of bacterial and fungal communities during the selective enrichment on different pollutants of a soil strongly polluted by mixtures of aliphatic and polycyclic hydrocarbons. Three consecutive enrichments were carried out on soil samples from different soil depths (0-1, 1-2, 2-3 m), and analyzed at each step by means of high-throughput sequencing of bacterial and fungal amplicons biomarkers. At the end of the enrichments, bacterial and fungal contaminants degrading strains were isolated and identified in order to (i) compare the composition of enriched communities by culture-dependent and culture-independent molecular methods and to (ii) obtain a collection of hydrocarbon degrading microorganisms potentially exploitable for soil bioremediation. Molecular results highlighted that for both bacteria and fungi the pollutant had a partial shaping effect on the enriched communities, with paraffin creating distinct enriched bacterial community from oil, and polycyclic aromatic hydrocarbons generally overlapping; interestingly neither the soil depth or the enrichment step had significant effects on the composition of the final enriched communities. Molecular analyses well-agreed with culture-dependent analyses in terms of most abundant microbial genera. A total of 95 bacterial and 94 fungal strains were isolated after selective enrichment procedure on different pollutants. On the whole, isolated bacteria where manly ascribed to Pseudomonas genus followed by Sphingobacterium, Bacillus, Stenothrophomonas, Achromobacter, and Serratia. As for fungi, Fusarium was the most abundant genus followed by Trichoderma and Aspergillus. The species comprising more isolates, such as Pseudomonas putida, Achromobacter xylosoxidans and Ochromobactrum anthropi for bacteria, Fusarium oxysporum and Fusarium solani for fungi, were also the dominant OTUs assessed in Illumina.
Collapse
Affiliation(s)
- Giulia Spini
- Department for Sustainable Food Processes, Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Federica Spina
- Department of Life Sciences and Systems Biology, Mycotheca Universitatis Taurinensis, University of Turin, Turin, Italy
| | - Anna Poli
- Department of Life Sciences and Systems Biology, Mycotheca Universitatis Taurinensis, University of Turin, Turin, Italy
| | | | | | | | - Giovanna C. Varese
- Department of Life Sciences and Systems Biology, Mycotheca Universitatis Taurinensis, University of Turin, Turin, Italy
| | - Edoardo Puglisi
- Department for Sustainable Food Processes, Università Cattolica del Sacro Cuore, Piacenza, Italy
| |
Collapse
|
31
|
McCormick MK, Whigham DF, Canchani-Viruet A. Mycorrhizal fungi affect orchid distribution and population dynamics. THE NEW PHYTOLOGIST 2018; 219:1207-1215. [PMID: 29790578 DOI: 10.1111/nph.15223] [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: 04/10/2018] [Accepted: 04/17/2018] [Indexed: 05/03/2023]
Abstract
Symbioses are ubiquitous in nature and influence individual plants and populations. Orchids have life history stages that depend fully or partially on fungi for carbon and other essential resources. As a result, orchid populations depend on the distribution of orchid mycorrhizal fungi (OMFs). We focused on evidence that local-scale distribution and population dynamics of orchids can be limited by the patchy distribution and abundance of OMFs, after an update of an earlier review confirmed that orchids are rarely limited by OMF distribution at geographic scales. Recent evidence points to a relationship between OMF abundance and orchid density and dormancy, which results in apparent density differences. Orchids were more abundant, less likely to enter dormancy, and more likely to re-emerge when OMF were abundant. We highlight the need for additional studies on OMF quantity, more emphasis on tropical species, and development and application of next-generation sequencing techniques to quantify OMF abundance in substrates and determine their function in association with orchids. Research is also needed to distinguish between OMFs and endophytic fungi and to determine the function of nonmycorrhizal endophytes in orchid roots. These studies will be especially important if we are to link orchids and OMFs in efforts to inform conservation.
Collapse
Affiliation(s)
- Melissa K McCormick
- Smithsonian Environmental Research Center, 647 Contees Wharf Rd, Edgewater, MD, 21037, USA
| | - Dennis F Whigham
- Smithsonian Environmental Research Center, 647 Contees Wharf Rd, Edgewater, MD, 21037, USA
| | - Armando Canchani-Viruet
- Smithsonian Environmental Research Center, 647 Contees Wharf Rd, Edgewater, MD, 21037, USA
- Universidad Metropolitana, Escuela de Ciencias y Tecnología, 1399 Avenida Ana G. Mendez, San Juan, 00926, Puerto Rico
| |
Collapse
|
32
|
Forin N, Nigris S, Voyron S, Girlanda M, Vizzini A, Casadoro G, Baldan B. Next Generation Sequencing of Ancient Fungal Specimens: The Case of the Saccardo Mycological Herbarium. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00129] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
33
|
Egidi E, May TW, Franks AE. Seeking the needle in the haystack: Undetectability of mycorrhizal fungi outside of the plant rhizosphere associated with an endangered Australian orchid. FUNGAL ECOL 2018. [DOI: 10.1016/j.funeco.2018.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
34
|
Jasinge NU, Huynh T, Lawrie AC. Changes in orchid populations and endophytic fungi with rainfall and prescribed burning in Pterostylis revoluta in Victoria, Australia. ANNALS OF BOTANY 2018; 121:321-334. [PMID: 29300863 PMCID: PMC5808809 DOI: 10.1093/aob/mcx164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/30/2017] [Indexed: 05/20/2023]
Abstract
Background and Aims Wildfires are common in seasonally dry parts of the world with a Mediterranean climate. Prescribed burning is used to reduce fuel load and fire risk, but often without reliable information on its effects. This study investigated the effects of prescribed burns in different seasons on Pterostylis revoluta, an autumn-flowering Australian terrestrial orchid, and its orchid mycorrhizal fungi (OMFs) to find the least damaging season for a prescribed burn. Methods Burns were conducted mid-season in spring and summer 2011 and autumn and winter 2012. Orchids were enumerated and measured during their flowering season in autumn 2011-2014 and mycorrhizal fungi were isolated before and after the burns in autumn 2011, 2012 and 2014. Micro-organisms isolated were characterized. DNA was extracted from the OMFs, and the internal transcribed spacer region was amplified by PCR. Amplicons were clustered by restriction fragment length polymorphism (RFLP), and representative amplicons were sequenced. OMF were tested for sensitivity to smoke water. Key Results The number of plants increased up to 4-fold and 90 % of plants became vegetative during this study. Isolation of mycorrhizal fungi increased and isolation of bacteria decreased. Before the burns, the main OMF isolated was unexpectedly Tulasnella calospora (Boud.) Juel. By 2014, after the burns, the expected Ceratobasidium sp. D.P. Rogers was the only OMF isolated in most burnt quadrats, whereas T. calospora was confined to a minority of unburnt 'control' and the 'spring burn' quadrats, which were also the only ones with flowering plants. Conclusions The decline in rainfall during 2010-2012 probably caused the switch from mainly flowering to mainly vegetative plants and the change in OMFs. Burning in spring to summer was less damaging to this orchid than burning in autumn to winter, which should be noted by authorities in fire management plans for fire-prone areas in which this orchid occurs.
Collapse
Affiliation(s)
- N U Jasinge
- School of Science, RMIT University (Bundoora West Campus), Bundoora, VIC, Australia
| | - T Huynh
- School of Science, RMIT University (Bundoora West Campus), Bundoora, VIC, Australia
| | - A C Lawrie
- School of Science, RMIT University (Bundoora West Campus), Bundoora, VIC, Australia
| |
Collapse
|
35
|
|
36
|
|