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Tian F, Wang J, Ding F, Wang L, Yang Y, Bai X, Tan C, Liao X. Comparative transcriptomics and proteomics analysis of the symbiotic germination of Paphiopedilum barbigerum with Epulorhiza sp. FQXY019. Front Microbiol 2024; 15:1358137. [PMID: 38562471 PMCID: PMC10982344 DOI: 10.3389/fmicb.2024.1358137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 03/06/2024] [Indexed: 04/04/2024] Open
Abstract
Introduction Paphiopedilum barbigerum is currently the rarest and most endangered species of orchids in China and has significant ornamental value. The mature seeds of P. barbigerum are difficult to germinate owing to the absence of an endosperm and are highly dependent on mycorrhizal fungi for germination and subsequent development. However, little is known about the regulation mechanisms of symbiosis and symbiotic germination of P. barbigerum seeds. Methods Herein, transcriptomics and proteomics were used to explore the changes in the P. barbigerum seeds after inoculation with (FQXY019 treatment group) or without (control group) Epulorhiza sp. FQXY019 at 90 days after germination. Results Transcriptome sequencing revealed that a total of 10,961 differentially expressed genes (DEGs; 2,599 upregulated and 8,402 downregulated) were identified in the control and FQXY019 treatment groups. These DEGs were mainly involved in carbohydrate, fatty acid, and amino acid metabolism. Furthermore, the expression levels of candidate DEGs related to nodulin, Ca2+ signaling, and plant lectins were significantly affected in P. barbigerum in the FQXY019 treatment groups. Subsequently, tandem mass tag-based quantitative proteomics was performed to recognize the differentially expressed proteins (DEPs), and a total of 537 DEPs (220 upregulated and 317 downregulated) were identified that were enriched in processes including photosynthesis, photosynthesis-antenna proteins, and fatty acid biosynthesis and metabolism. Discussion This study provides novel insight on the mechanisms underlying the in vitro seed germination and protocorm development of P. barbigerum by using a compatible fungal symbiont and will benefit the reintroduction and mycorrhizal symbiotic germination of endangered orchids.
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Affiliation(s)
- Fan Tian
- Guizhou Academy of Forestry, Guiyang, Guizhou, China
- Key Laboratory for Biodiversity Conservation in the Karst Mountain Area of Southwestern China, National Forestry and Grassland Administration, Guiyang, Guizhou, China
| | - Juncai Wang
- Guizhou Academy of Sciences, Guiyang, Guizhou, China
| | - Fangjun Ding
- Guizhou Academy of Forestry, Guiyang, Guizhou, China
- Key Laboratory for Biodiversity Conservation in the Karst Mountain Area of Southwestern China, National Forestry and Grassland Administration, Guiyang, Guizhou, China
| | - Lianhui Wang
- Guizhou Academy of Forestry, Guiyang, Guizhou, China
- Key Laboratory for Biodiversity Conservation in the Karst Mountain Area of Southwestern China, National Forestry and Grassland Administration, Guiyang, Guizhou, China
| | - Yanbing Yang
- Guizhou Academy of Forestry, Guiyang, Guizhou, China
- Key Laboratory for Biodiversity Conservation in the Karst Mountain Area of Southwestern China, National Forestry and Grassland Administration, Guiyang, Guizhou, China
| | - Xinxiang Bai
- College of Forestry, Guizhou University, Guiyang, Guizhou, China
| | - Chengjiang Tan
- Guizhou Maolan National Nature Reserve Administration, Libo, Guizhou, China
| | - Xiaofeng Liao
- Guizhou Academy of Sciences, Guiyang, Guizhou, China
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Tian F, Wang JC, Bai XX, Yang YB, Huang L, Liao XF. Symbiotic seed germination and seedling growth of mycorrhizal fungi in Paphiopedilum hirsutissimun (Lindl.Ex Hook.) Stein from China. Plant Signal Behav 2023; 18:2293405. [PMID: 38104263 PMCID: PMC10730140 DOI: 10.1080/15592324.2023.2293405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/11/2023] [Indexed: 12/19/2023]
Abstract
Similar to other orchid species, Paphiopedilum hirsutissimum (Lindl.ex Hook.) Stein, relies on nutrients provided by mycorrhizal fungus for seed germination and seedling development in the wild owing to a lack of endosperm in its seeds. Therefore, obtaining suitable and specialized fungi to enhance seed germination, seedling formation, and further development is considered a powerful tool for orchid seedling propagation, reintroduction, and species conservation. In this study, we investigated the diversity, abundance, and frequency of endophytic fungal strains in the root organs of P. hirsutissimum. One family and five genera of the fungi were isolated and identified through rDNA-ITS sequencing. The ability of isolated fungi to germinate in vitro from the seeds of this species was evaluated, and the development of P. hirsutissimum protocorm has been described. The findings showed that the treatments inoculated with endophytic fungal DYXY033 may successfully support the advanced developmental stage of seedlings up to stage 5. In addition, scanning electron microscopy (SEM) revealed that the mycelium of this strain began to invade from either end of the seeds up to the embryo, extending rapidly from the inside to the outside. Its lengthening resulted in the bursting of the seed coat to form protocorms, which developed into seedlings. The results showed that DYXY033 has a high degree of mycobiont specificity under in vitro symbiotic seed germination conditions and is a representative mycorrhizal fungus with ecological value for the species. In summary, this strain may particularly be significant for the protection of P. hirsutissimum species that are endangered in China. In the long run, it may also contribute to global efforts in reintroducing orchid species and in realizing in situ restorations of threatened orchid populations.
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Affiliation(s)
- Fan Tian
- Guizhou Academy of Forestry, Guiyang, Guizhou, China
- Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, Guiyang, Guizhou, China
| | - Jun-Cai Wang
- Advanced Technology and Materials Research Institute, Guizhou Academy of Sciences, Guiyang, Guizhou, China
| | - Xin-Xiang Bai
- College of Forestry, Guizhou University, Guiyang, Guizhou, China
| | - Yan-Bing Yang
- Guizhou Academy of Forestry, Guiyang, Guizhou, China
- Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, Guiyang, Guizhou, China
| | - Lang Huang
- Guizhou Academy of Forestry, Guiyang, Guizhou, China
- Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, Guiyang, Guizhou, China
| | - Xiao-Feng Liao
- Advanced Technology and Materials Research Institute, Guizhou Academy of Sciences, Guiyang, Guizhou, China
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Chen J, Tang Y, Kohler A, Lebreton A, Xing Y, Zhou D, Li Y, Martin FM, Guo S. Comparative Transcriptomics Analysis of the Symbiotic Germination of D. officinale (Orchidaceae) With Emphasis on Plant Cell Wall Modification and Cell Wall-Degrading Enzymes. Front Plant Sci 2022; 13:880600. [PMID: 35599894 PMCID: PMC9120867 DOI: 10.3389/fpls.2022.880600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/04/2022] [Indexed: 06/15/2023]
Abstract
Orchid seed germination in nature is an extremely complex physiological and ecological process involving seed development and mutualistic interactions with a restricted range of compatible mycorrhizal fungi. The impact of the fungal species' partner on the orchids' transcriptomic and metabolic response is still unknown. In this study, we performed a comparative transcriptomic analysis between symbiotic and asymbiotic germination at three developmental stages based on two distinct fungi (Tulasnella sp. and Serendipita sp.) inoculated to the same host plant, Dendrobium officinale. Differentially expressed genes (DEGs) encoding important structural proteins of the host plant cell wall were identified, such as epidermis-specific secreted glycoprotein, proline-rich receptor-like protein, and leucine-rich repeat (LRR) extensin-like protein. These DEGs were significantly upregulated in the symbiotic germination stages and especially in the protocorm stage (stage 3) and seedling stage (stage 4). Differentially expressed carbohydrate-active enzymes (CAZymes) in symbiotic fungal mycelium were observed, they represented 66 out of the 266 and 99 out of the 270 CAZymes annotated in Tulasnella sp. and Serendipita sp., respectively. These genes were speculated to be involved in the reduction of plant immune response, successful colonization by fungi, or recognition of mycorrhizal fungi during symbiotic germination of orchid seed. Our study provides important data to further explore the molecular mechanism of symbiotic germination and orchid mycorrhiza and contribute to a better understanding of orchid seed biology.
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Affiliation(s)
- Juan Chen
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yanjing Tang
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Annegret Kohler
- Université de Lorraine, INRAE, UMR Interactions Arbres/Microorganismes, INRAE Grand Est - Nancy, Champenoux, France
| | - Annie Lebreton
- Université de Lorraine, INRAE, UMR Interactions Arbres/Microorganismes, INRAE Grand Est - Nancy, Champenoux, France
| | - Yongmei Xing
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Dongyu Zhou
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yang Li
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Francis M. Martin
- Université de Lorraine, INRAE, UMR Interactions Arbres/Microorganismes, INRAE Grand Est - Nancy, Champenoux, France
| | - Shunxing Guo
- Key Laboratory of Bioactive Substances and Resource Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Sisti LS, Flores-Borges DNA, de Andrade SAL, Koehler S, Bonatelli ML, Mayer JLS. The Role of Non-Mycorrhizal Fungi in Germination of the Mycoheterotrophic Orchid Pogoniopsis schenckii Cogn. Front Plant Sci 2019; 10:1589. [PMID: 31850049 PMCID: PMC6896934 DOI: 10.3389/fpls.2019.01589] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/12/2019] [Indexed: 05/04/2023]
Abstract
Endophytic fungi are those that inhabit within organs and tissues without causing damage, while mycorrhizal fungi develop hyphal complexes called pelotons within cortical cells of orchid roots. Although abundant and frequent in all plant organs, the role of endophytic fungi has been neglected in relation to orchid's early development. Pogoniopsis schenckii Cogn. is an aclorophyllated and mycoheterotrophic (MH) orchid. This study aimed at i) investigating the endophytic fungal community in organs of P. schenckii and its mycorrhizal fungi associated; ii) evaluating the ability of isolated fungus in the in vitro germination of the seeds of the species, and iii) describing the development of P. schenckii protocorm, analyzing the ultrastructure of the infected cells. Six genera of fungi were isolated and identified through the partial sequencing of the internal transcribed spacer region, all belonging to the phylum Ascomycota. Also, Tulasnellaceae was identified through uncultured technique as potentially mycorrhizal in this MH orchid. Some isolates of the genera Trichoderma, Fusarium, and especially Clonostachys presented germinative potential on P. schenckii seeds, causing rupture of the external tegument. The protocorms showed complete absence of peloton formation, but fungal hyphae were clearly observed within living cells. This is the first report of germination of a MH and aclorophyllated orchid species stimulated by the presence of non-mycorrhizal endophytic fungi isolated from fruits and roots of the same species.
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Affiliation(s)
- Laís Soêmis Sisti
- Laboratory of Plant Anatomy, Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, Brazil
| | | | - Sara Adrián López de Andrade
- Laboratory of Plant Molecular Physiology, Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, Brazil
| | - Samantha Koehler
- Laboratory of Plant Taxonomy, Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, Brazil
| | - Maria Letícia Bonatelli
- Laboratory of Genetics of Microorganisms, Department of Genetics, College of Agriculture “Luiz de Queiroz,” University of São Paulo, Piracicaba, Brazil
| | - Juliana Lischka Sampaio Mayer
- Laboratory of Plant Anatomy, Department of Plant Biology, Institute of Biology, State University of Campinas, Campinas, Brazil
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Miura C, Saisho M, Yagame T, Yamato M, Kaminaka H. Bletilla striata (Orchidaceae) Seed Coat Restricts the Invasion of Fungal Hyphae at the Initial Stage of Fungal Colonization. Plants (Basel) 2019; 8:E280. [PMID: 31405202 PMCID: PMC6724134 DOI: 10.3390/plants8080280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/05/2019] [Accepted: 08/08/2019] [Indexed: 12/02/2022]
Abstract
Orchids produce minute seeds that contain limited or no endosperm, and they must form an association with symbiotic fungi to obtain nutrients during germination and subsequent seedling growth under natural conditions. Orchids need to select an appropriate fungus among diverse soil fungi at the germination stage. However, there is limited understanding of the process by which orchids recruit fungal associates and initiate the symbiotic interaction. This study aimed to better understand this process by focusing on the seed coat, the first point of fungal attachment. Bletilla striata seeds, some with the seed coat removed, were prepared and sown with symbiotic fungi or with pathogenic fungi. The seed coat-stripped seeds inoculated with the symbiotic fungi showed a lower germination rate than the intact seeds, and proliferated fungal hyphae were observed inside and around the stripped seeds. Inoculation with the pathogenic fungi increased the infection rate in the seed coat-stripped seeds. The pathogenic fungal hyphae were arrested at the suspensor side of the intact seeds, whereas the seed coat-stripped seeds were subjected to severe infestation. These results suggest that the seed coat restricts the invasion of fungal hyphae and protects the embryo against the attack of non-symbiotic fungi.
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Affiliation(s)
- Chihiro Miura
- Faculty of Agriculture, Tottori University, 4-101 Koyama Minami, Tottori 680-8553, Japan
| | - Miharu Saisho
- Faculty of Agriculture, Tottori University, 4-101 Koyama Minami, Tottori 680-8553, Japan
| | - Takahiro Yagame
- Mizuho Kyo-do Museum, 316-5 Komagatafujiyama, Mizuho, Tokyo 190-1202, Japan
| | - Masahide Yamato
- Faculty of Education, Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522, Japan
| | - Hironori Kaminaka
- Faculty of Agriculture, Tottori University, 4-101 Koyama Minami, Tottori 680-8553, Japan.
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Li YY, Chen XM, Zhang Y, Cho YH, Wang AR, Yeung EC, Zeng X, Guo SX, Lee YI. Immunolocalization and Changes of Hydroxyproline-Rich Glycoproteins During Symbiotic Germination of Dendrobium officinale. Front Plant Sci 2018; 9:552. [PMID: 29922306 PMCID: PMC5996918 DOI: 10.3389/fpls.2018.00552] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 04/09/2018] [Indexed: 05/11/2023]
Abstract
Hydroxyproline-rich glycoproteins (HRGPs) are abundant cell wall components involved in mycorrhizal symbiosis, but little is known about their function in orchid mycorrhizal association. To gain further insight into the role of HRGPs in orchid symbiosis, the location and function of HRGPs were investigated during symbiotic germination of Dendrobium officinale. The presence of JIM11 epitope in developing protocorms was determined using immunodot blots and immunohistochemical staining procedures. Real-time PCR was also employed to verify the expression patterns of genes coding for extensin-like genes selected from the transcriptomic database. The importance of HRGPs in symbiotic germination was further investigated using 3,4-dehydro-L-proline (3,4-DHP), an inhibitor of HRGP biosynthesis. In symbiotic cultures, immunodot blots of JIM11 signals were moderate in mature seeds, and the signals became stronger in swollen embryos. After germination, signal intensities decreased in developing protocorms. In contrast, in asymbiotic cultures, JIM11 signals were much lower as compared with those stages in symbiotic cultures. Immunofluorescence staining enabled the visualization of JIM11 epitope in mature embryo and protocorm cells. Positive signals were initially localized in the larger cells near the basal (suspensor) end of uninfected embryos, marking the future colonization site of fungal hyphae. After 1 week of inoculation, the basal end of embryos had been colonized, and a strong signal was detected mostly at the mid- and basal regions of the enlarging protocorm. As protocorm development progressed, the signal was concentrated in the colonized cells at the basal end. In colonized cells, signals were present in the walls and intracellularly associated with hyphae and the pelotons. The precise localization of JIM11 epitope is further examined by immunogold labeling. In the colonized cells, gold particles were found mainly in the cell wall and the interfacial matrix near the fungal cell wall. Four extensin-like genes were verified to be highly up-regulated in symbiotically germinated protocorms as compared to asymbiotically germinated ones. The 3,4-DHP treatment inhibited the accumulation of HRGPs and symbiotic seed germination. In these protocorms, fungal hyphae could be found throughout the protocorms. Our results indicate that HRGPs play an important role in symbiotic germination. They can serve as markers for fungal colonization, establishing a symbiotic compartment and constraining fungal colonization inside the basal cells of protocorms.
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Affiliation(s)
- Yuan-Yuan Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao-Mei Chen
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ying Zhang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yu-Hsiu Cho
- Biology Department, National Museum of Natural Science, Taichung, Taiwan
| | - Ai-Rong Wang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Edward C. Yeung
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Xu Zeng
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shun-Xing Guo
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yung-I Lee
- Biology Department, National Museum of Natural Science, Taichung, Taiwan
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
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Ogura-Tsujita Y, Gebauer G, Xu H, Fukasawa Y, Umata H, Tetsuka K, Kubota M, Schweiger JMI, Yamashita S, Maekawa N, Maki M, Isshiki S, Yukawa T. The giant mycoheterotrophic orchid Erythrorchis altissima is associated mainly with a divergent set of wood-decaying fungi. Mol Ecol 2018; 27:1324-1337. [PMID: 29419910 DOI: 10.1111/mec.14524] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/14/2018] [Accepted: 01/19/2018] [Indexed: 11/28/2022]
Abstract
The climbing orchid Erythrorchis altissima is the largest mycoheterotroph in the world. Although previous in vitro work suggests that E. altissima has a unique symbiosis with wood-decaying fungi, little is known about how this giant orchid meets its carbon and nutrient demands exclusively via mycorrhizal fungi. In this study, the mycorrhizal fungi of E. altissima were molecularly identified using root samples from 26 individuals. Furthermore, in vitro symbiotic germination with five fungi and stable isotope compositions in five E. altissima at one site were examined. In total, 37 fungal operational taxonomic units (OTUs) belonging to nine orders in Basidiomycota were identified from the orchid roots. Most of the fungal OTUs were wood-decaying fungi, but underground roots had ectomycorrhizal Russula. Two fungal isolates from mycorrhizal roots induced seed germination and subsequent seedling development in vitro. Measurement of carbon and nitrogen stable isotope abundances revealed that E. altissima is a full mycoheterotroph whose carbon originates mainly from wood-decaying fungi. All of the results show that E. altissima is associated with a wide range of wood- and soil-inhabiting fungi, the majority of which are wood-decaying taxa. This generalist association enables E. altissima to access a large carbon pool in woody debris and has been key to the evolution of such a large mycoheterotroph.
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Affiliation(s)
| | - Gerhard Gebauer
- Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Hui Xu
- Botanical Gardens, Tohoku University, Aoba-ku, Sendai, Japan
| | - Yu Fukasawa
- Graduate School of Agricultural Science, Tohoku University, Osaki, Miyagi, Japan
| | - Hidetaka Umata
- Faculty of Agriculture, Kagoshima University, Korimoto, Kagoshima, Japan
| | - Kenshi Tetsuka
- Yakushima Yakutane-goyo Reseaech Group, Yakushima-machi, Kagoshima, Japan
| | - Miho Kubota
- Faculty of Agriculture, Saga University, Saga, Japan
| | - Julienne M-I Schweiger
- Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Satoshi Yamashita
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Minami-Josanjima, Tokushima, Japan
| | - Nitaro Maekawa
- Faculty of Agriculture, Tottori University, Koyamaminami, Tottori, Japan
| | - Masayuki Maki
- Botanical Gardens, Tohoku University, Aoba-ku, Sendai, Japan
| | - Shiro Isshiki
- Faculty of Agriculture, Saga University, Saga, Japan
| | - Tomohisa Yukawa
- Tsukuba Botanical Garden, National Museum of Nature and Science, Tsukuba, Ibaraki, Japan
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Johansson VA, Bahram M, Tedersoo L, Kõljalg U, Eriksson O. Specificity of fungal associations of Pyroleae and Monotropa hypopitys during germination and seedling development. Mol Ecol 2017; 26:2591-2604. [PMID: 28173637 DOI: 10.1111/mec.14050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 11/23/2016] [Accepted: 01/17/2017] [Indexed: 01/15/2023]
Abstract
Mycoheterotrophic plants obtain organic carbon from associated mycorrhizal fungi, fully or partially. Angiosperms with this form of nutrition possess exceptionally small 'dust seeds' which after germination develop 'seedlings' that remain subterranean for several years, fully dependent on fungi for supply of carbon. Mycoheterotrophs which as adults have photosynthesis thus develop from full to partial mycoheterotrophy, or autotrophy, during ontogeny. Mycoheterotrophic plants may represent a gradient of variation in a parasitism-mutualism continuum, both among and within species. Previous studies on plant-fungal associations in mycoheterotrophs have focused on either germination or the adult life stages of the plant. Much less is known about the fungal associations during development of the subterranean seedlings. We investigated germination and seedling development and the diversity of fungi associated with germinating seeds and subterranean seedlings (juveniles) in five Monotropoideae (Ericaceae) species, the full mycoheterotroph Monotropa hypopitys and the putatively partial mycoheterotrophs Pyrola chlorantha, P. rotundifolia, Moneses uniflora and Chimaphila umbellata. Seedlings retrieved from seed sowing experiments in the field were used to examine diversity of fungal associates, using pyrosequencing analysis of ITS2 region for fungal identification. The investigated species varied with regard to germination, seedling development and diversity of associated fungi during juvenile ontogeny. Results suggest that fungal host specificity increases during juvenile ontogeny, most pronounced in the fully mycoheterotrophic species, but a narrowing of fungal associates was found also in two partially mycoheterotrophic species. We suggest that variation in specificity of associated fungi during seedling ontogeny in mycoheterotrophs represents ongoing evolution along a parasitism-mutualism continuum.
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Affiliation(s)
- V A Johansson
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE 106 91, Stockholm, Sweden
| | - M Bahram
- Institute of Ecology and Earth Sciences, University of Tartu, 51005, Tartu, Estonia.,Department of Organismal Biology, Uppsala University, SE 75236, Uppsala, Sweden
| | - L Tedersoo
- Institute of Ecology and Earth Sciences, University of Tartu, 51005, Tartu, Estonia
| | - U Kõljalg
- Institute of Ecology and Earth Sciences, University of Tartu, 51005, Tartu, Estonia
| | - O Eriksson
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE 106 91, Stockholm, Sweden
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Jiang JH, Lee YI, Cubeta MA, Chen LC. Characterization and colonization of endomycorrhizal Rhizoctonia fungi in the medicinal herb Anoectochilus formosanus (Orchidaceae). Mycorrhiza 2015; 25:431-45. [PMID: 25575732 PMCID: PMC4512280 DOI: 10.1007/s00572-014-0616-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 10/27/2014] [Indexed: 05/03/2023]
Abstract
The medicinal effects and techniques for cultivating Anoectochilus formosanus are well-documented, but little is known about the mycorrhizal fungi associated with A. formosanus. Rhizoctonia (Thanatephorus) anastomosis group 6 (AG-6) was the most common species isolated from fungal pelotons in native A. formosanus and represented 67% of the sample. Rhizoctonia (Ceratobasidium) AG-G, P, and R were also isolated and represent the first occurrence in the Orchidaceae. Isolates of AG-6, AG-R, and AG-P in clade I increased seed germination 44-91% and promoted protocorm growth from phases III to VI compared to asymbiotic treatments and isolates of AG-G in clade II and Tulasnella species in clade III. All isolates in clades I to III formed fungal pelotons in tissue-cultured seedlings of A. formosanus, which exhibited significantly greater growth than nonmycorrhizal seedlings. An analysis of the relative effect of treatment ([Formula: see text]) showed that the low level of colonization ([Formula: see text]) by isolates in clade I resulted in a significant increase in seedling growth compared to isolates in clades II (0.63-0.82) and III (0.63-0.75). There was also a negative correlation (r = -0.8801) with fresh plant weight and fungal colonization. Our results suggest that isolates in clade I may represent an important group associated with native populations of A. formosanus and can vary in their ability to establish a symbiotic association with A. formosanus. The results presented here are potentially useful for advancing research on the medicinal properties, production, and conservation of A. formosanus in diverse ecosystems.
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Affiliation(s)
- Jr-Hau Jiang
- Department of Plant Pathology, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung, Taiwan
| | - Yung-I Lee
- Botany Department, National Museum of Natural Science, No. 1, Kuan-Chien Road, Taichung, Taiwan
| | - Marc A. Cubeta
- Department of Plant Pathology, Center for Integrated Fungal Research, North Carolina State University, Raleigh, NC 27695 USA
| | - Lung-Chung Chen
- Department of Plant Pathology, National Chung Hsing University, No. 250, Kuo-Kuang Road, Taichung, Taiwan
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McKENDRICK SL, Leake JR, Taylor DL, Read DJ. Symbiotic germination and development of myco-heterotrophic plants in nature: ontogeny of Corallorhiza trifida and characterization of its mycorrhizal fungi. New Phytol 2000; 145:523-537. [PMID: 33862904 DOI: 10.1046/j.1469-8137.2000.00603.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The processes of symbiotic germination and seedling development were analysed in the myco-heterotrophic orchid Corallorhiza trifida, seeds of which were buried in 'packets' either adjacent to or at varying distances from adult plants in defined communities of ectomycorrhizal tree species. Germination occurred within eight months of burial under Betula-Alnus and within seven months under Salix repens. It was always associated with penetration of the suspensor by a clamp-forming mycorrhizal fungus. Four distinct developmental stages were defined and the rates of transition through these stages were plotted. There was no evidence of a relationship between extent of germination or rate of development and the presence of naturally distributed plants of C. trifida at the spatial scale of 1 m. The best germination and the most rapid rate of development of C. trifida seedlings occurred in a Salix repens community located at a considerable distance from any extant C. trifida population. Determination of internal transcribed spacer (ITS) RFLPs and of gene sequences of the fungi involved in symbiotic germination and growth of C. trifida, revealed them to belong exclusively to the Thelephora-Tomentella complex of the Thelephoraceae. These fungi are known also to be ectomycorrhizal associates of trees. It is hypothesized that the rate of growth of the C. trifida seedlings is determined by the ability of the fungal symbionts to transfer carbon from their ectomycorrhizal co-associates.
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Affiliation(s)
- S L McKENDRICK
- 1 Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - J R Leake
- 1 Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - D L Taylor
- 1 Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - D J Read
- 1 Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
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