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Veltman MA, Anthoons B, Schrøder-Nielsen A, Gravendeel B, de Boer HJ. Orchidinae-205: A new genome-wide custom bait set for studying the evolution, systematics, and trade of terrestrial orchids. Mol Ecol Resour 2024; 24:e13986. [PMID: 38899721 DOI: 10.1111/1755-0998.13986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 05/16/2024] [Accepted: 05/30/2024] [Indexed: 06/21/2024]
Abstract
Terrestrial orchids are a group of genetically understudied, yet culturally and economically important plants. The Orchidinae tribe contains many species that produce edible tubers that are used for the production of traditional delicacies collectively called 'salep'. Overexploitation of wild orchids in the Eastern Mediterranean and Western Asia threatens to drive many of these species to extinction, but cost-effective tools for monitoring their trade are currently lacking. Here we present a custom bait kit for target enrichment and sequencing of 205 novel genetic markers that are tailored to phylogenomic applications in Orchidinae s.l. A subset of 31 markers capture genes putatively involved in the production of glucomannan, a water-soluble polysaccharide that gives salep its distinctive properties. We tested the kit on 73 taxa native to the area, demonstrating universally high locus recovery irrespective of species identity, that exceeds the total sequence length obtained with alternative kits currently available. Phylogenetic inference with concatenation and coalescent approaches was robust and showed high levels of support for most clades, including some which were previously unresolved. Resolution for hybridizing and recently radiated lineages remains difficult, but could be further improved by analysing multiple haplotypes and the non-exonic sequences captured by our kit, with the promise to shed new light on the evolution of enigmatic taxa with a complex speciation history. Offering a step-up from traditional barcoding and universal markers, the genome-wide custom loci targeted by Orchidinae-205 are a valuable new resource to study the evolution, systematics and trade of terrestrial orchids.
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Affiliation(s)
- Margaretha A Veltman
- Natural History Museum, Oslo, Norway
- Naturalis Biodiversity Center, Leiden, Netherlands
| | | | | | - Barbara Gravendeel
- Naturalis Biodiversity Center, Leiden, Netherlands
- Radboud Institute for Biological and Environmental Sciences, Radboud University, Nijmegen, Netherlands
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Sidharthan VK, Reddy V, Kiran G, Rajeswari V, Baranwal VK, Kumar MK, Kumar KS. Probing of plant transcriptomes reveals the hidden genetic diversity of the family Secoviridae. Arch Virol 2024; 169:150. [PMID: 38898334 DOI: 10.1007/s00705-024-06076-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 05/07/2024] [Indexed: 06/21/2024]
Abstract
Secoviruses are single-stranded RNA viruses that infect plants. In the present study, we identified 61 putative novel secoviral genomes in various plant species by mining publicly available plant transcriptome data. These viral sequences represent the genomes of 13 monopartite and 48 bipartite secovirids. The genome sequences of 52 secovirids were coding-complete, and nine were partial. Except for small open reading frames (ORFs) determined in waikaviral genomes and RNA2 of torradoviruses, all of the recovered genomes/genome segments contained a large ORF encoding a polyprotein. Based on genome organization and phylogeny, all but three of the novel secoviruses were assigned to different genera. The genome organization of two identified waika-like viruses resembled that of the recently identified waika-like virus Triticum aestivum secovirus. Phylogenetic analysis revealed a pattern of host-virus co-evolution in a few waika- and waika-like viruses and increased phylogenetic diversity of nepoviruses. The study provides a basis for further investigation of the biological properties of these novel secoviruses.
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Affiliation(s)
- V Kavi Sidharthan
- Division of Genetics and Tree Improvement, ICFRE-Institute of Forest Biodiversity, Hyderabad, India.
| | - Vijayprakash Reddy
- Division of Genetics and Tree Improvement, ICFRE-Institute of Forest Biodiversity, Hyderabad, India
| | - G Kiran
- Division of Genetics and Tree Improvement, ICFRE-Institute of Forest Biodiversity, Hyderabad, India
| | - V Rajeswari
- School of Agricultural Sciences, Malla Reddy University, Hyderabad, India
| | - V K Baranwal
- Division of Plant Pathology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - M Kiran Kumar
- Division of Genetics and Tree Improvement, ICFRE-Institute of Forest Biodiversity, Hyderabad, India
| | - K Sudheer Kumar
- Division of Genetics and Tree Improvement, ICFRE-Institute of Forest Biodiversity, Hyderabad, India
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Wong DCJ, Wang Z, Perkins J, Jin X, Marsh GE, John EG, Peakall R. The road less taken: Dihydroflavonol 4-reductase inactivation and delphinidin anthocyanin loss underpins a natural intraspecific flower colour variation. Mol Ecol 2024:e17334. [PMID: 38651763 DOI: 10.1111/mec.17334] [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: 11/14/2023] [Revised: 02/22/2024] [Accepted: 03/20/2024] [Indexed: 04/25/2024]
Abstract
Visual cues are of critical importance for the attraction of animal pollinators, however, little is known about the molecular mechanisms underpinning intraspecific floral colour variation. Here, we combined comparative spectral analysis, targeted metabolite profiling, multi-tissue transcriptomics, differential gene expression, sequence analysis and functional analysis to investigate a bee-pollinated orchid species, Glossodia major with common purple- and infrequent white-flowered morphs. We found uncommon and previously unreported delphinidin-based anthocyanins responsible for the conspicuous and pollinator-perceivable colour of the purple morph and three genetic changes underpinning the loss of colour in the white morph - (1) a loss-of-function (LOF; frameshift) mutation affecting dihydroflavonol 4-reductase (DFR1) coding sequence due to a unique 4-bp insertion, (2) specific downregulation of functional DFR1 expression and (3) the unexpected discovery of chimeric Gypsy transposable element (TE)-gene (DFR) transcripts with potential consequences to the genomic stability and post-transcriptional or epigenetic regulation of DFR. This is one of few known cases where regulatory changes and LOF mutation in an anthocyanin structural gene, rather than transcription factors, are important. Furthermore, if TEs prove to be a frequent source of mutation, the interplay between environmental stress-induced TE evolution and pollinator-mediated selection for adaptive colour variation may be an overlooked mechanism maintaining floral colour polymorphism in nature.
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Affiliation(s)
- Darren C J Wong
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Zemin Wang
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, China
- College of Life Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - James Perkins
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Xin Jin
- State Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou, China
- College of Life Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Grace Emma Marsh
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Emma Grace John
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Rod Peakall
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
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Phillips RD, Bohman B, Peakall R, Reiter N. Sexual attraction with pollination during feeding behaviour: implications for transitions between specialized strategies. ANNALS OF BOTANY 2024; 133:273-286. [PMID: 37963103 PMCID: PMC11005785 DOI: 10.1093/aob/mcad178] [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: 08/27/2023] [Accepted: 11/13/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND AND AIMS Understanding the origin of pollination by sexual deception has proven challenging, as sexually deceptive flowers are often highly modified, making it hard to resolve how any intermediate forms between sexual deception and an ancestral strategy might have functioned. Here, we report the discovery in Caladenia (Orchidaceae) of sexual attraction with pollination during feeding behaviour, which may offer important clues for understanding shifts in pollination strategy. METHODS For Caladenia robinsonii, we observed the behaviour of its male wasp pollinator, Phymatothynnus aff. nitidus (Thynnidae), determined the site of release of the sexual attractant, and experimentally evaluated if the position of the attractant influences rates of attempted copulation and feeding behaviour. We applied GC-MS to test for surface sugar on the labellum. To establish if this pollination strategy is widespread in Caladenia, we conducted similar observations and experiments for four other Caladenia species. KEY RESULTS In C. robinsonii, long-range sexual attraction of the pollinator is via semiochemicals emitted from the glandular sepal tips. Of the wasps landing on the flower, 57 % attempted copulation with the sepal tips, while 27 % attempted to feed from the base of the labellum, the behaviour associated with pollen transfer. A similar proportion of wasps exhibited feeding behaviour when the site of odour release was manipulated. A comparable pollination strategy occurs in another phylogenetically distinct clade of Caladenia. CONCLUSIONS We document a previously overlooked type of sexual deception for orchids involving long-distance sexual attraction, but with pollination occurring during feeding behaviour at the labellum. We show this type of sexual deception operates in other Caladenia species and predict that it is widespread across the genus. Our findings may offer clues about how an intermediate transitional strategy from a food-rewarding or food-deceptive ancestor operated during the evolution of sexual deception.
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Affiliation(s)
- Ryan D Phillips
- Department of Environment and Genetics and the Research Centre for Future Landscapes, La Trobe University, Melbourne, Victoria 3086, Australia
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Royal Botanic Gardens Victoria, Science Division, Corner of Ballarto Road and Botanic Drive, Cranbourne, VIC 3977, Australia
- Kings Park and Botanic Garden, The Botanic Garden and Parks Authority, West Perth, WA 6005, Australia
| | - Björn Bohman
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Department of Plant Protection Biology, the Swedish University of Agricultural Sciences, Lomma 23422, Sweden
- School of Molecular Sciences, The University of Western Australia Crawley, WA 6009Australia
| | - Rod Peakall
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
| | - Noushka Reiter
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
- Royal Botanic Gardens Victoria, Science Division, Corner of Ballarto Road and Botanic Drive, Cranbourne, VIC 3977, Australia
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Arifin AR, Phillips RD, Linde CC. Strong phylogenetic congruence between Tulasnella fungi and their associated Drakaeinae orchids. J Evol Biol 2023; 36:221-237. [PMID: 36309962 PMCID: PMC10091943 DOI: 10.1111/jeb.14107] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 01/11/2023]
Abstract
The study of congruency between phylogenies of interacting species can provide a powerful approach for understanding the evolutionary history of symbiotic associations. Orchid mycorrhizal fungi can survive independently of orchids making cospeciation unlikely, leading us to predict that any congruence would arise from host-switches to closely related fungal species. The Australasian orchid subtribe Drakaeinae is an iconic group of sexually deceptive orchids that consists of approximately 66 species. In this study, we investigated the evolutionary relationships between representatives of all six Drakaeinae orchid genera (39 species) and their mycorrhizal fungi. We used an exome capture dataset to generate the first well-resolved phylogeny of the Drakaeinae genera. A total of 10 closely related Tulasnella Operational Taxonomic Units (OTUs) and previously described species were associated with the Drakaeinae orchids. Three of them were shared among orchid genera, with each genus associating with 1-6 Tulasnella lineages. Cophylogenetic analyses show Drakaeinae orchids and their Tulasnella associates exhibit significant congruence (p < 0.001) in the topology of their phylogenetic trees. An event-based method also revealed significant congruence in Drakaeinae-Tulasnella relationships, with duplications (35), losses (25), and failure to diverge (9) the most frequent events, with minimal evidence for cospeciation (1) and host-switches (2). The high number of duplications suggests that the orchids speciate independently from the fungi, and the fungal species association of the ancestral orchid species is typically maintained in the daughter species. For the Drakaeinae-Tulasnella interaction, a pattern of phylogenetic niche conservatism rather than coevolution likely explains the observed phylogenetic congruency in orchid and fungal phylogenies. Given that many orchid genera are characterized by sharing of fungal species between closely related orchid species, we predict that these findings may apply to a wide range of orchid lineages.
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Affiliation(s)
- Arild R Arifin
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.,Department of Plant Pathology, Washington State University Tree Fruit Research and Extension Center, Wenatchee, Washington, USA
| | - Ryan D Phillips
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia.,Department of Ecology, Environment & Evolution, La Trobe University, Bundoora, Victoria, Australia.,Department of Biodiversity, Conservation and Attractions, Kings Park Science, Perth, Western Australia, Australia.,Royal Botanic Gardens Victoria, Victoria, Australia
| | - Celeste C Linde
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
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Wong DCJ, Perkins J, Peakall R. Conserved pigment pathways underpin the dark insectiform floral structures of sexually deceptive Chiloglottis (Orchidaceae). FRONTIERS IN PLANT SCIENCE 2022; 13:976283. [PMID: 36275580 PMCID: PMC9581149 DOI: 10.3389/fpls.2022.976283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/24/2022] [Indexed: 06/10/2023]
Abstract
Sexually deceptive plants achieve pollination by enticing specific male insects as pollinators using a combination of olfactory, visual, and morphological mimicry. The sexually deceptive orchid genus Chiloglottis is comprised of some 30 species with predominantly dull green-red flowers except for the dark insectiform calli/callus structure from the labellum lamina. This unique structure mimics the female of the pollinator and potentially enhances the visibility of the mimic. However, the chemical and genetic basis for the color of these structures remains poorly understood across the genus. The goal of this study was to investigate the flower color biochemistry and patterns of gene expression across the anthocyanin and flavonol glycoside biosynthetic pathway within the calli structures across the three distinct clades of Chiloglottis (Formicifera, Reflexa, and Valida) using chemical and transcriptome analysis. Our phylogenomic analysis confirmed the close sister relationship between the Reflexa/Formicifera clades and reaffirms the basal position of the Valida clade. Additionally, the biochemical basis of the dark calli/callus structures is conserved across the genus. Nonetheless, the proportion of methoxylated anthocyanin and flavonol glycoside derivatives and the mean gene expression levels appear to differentiate the Reflexa and Formicifera clades from the Valida clade. In future studies, it will be of interest to tease apart the role of phylogeny, environment, pollinators, and other factors as potential drivers of the observed biochemistry and gene expression differences. It will also be important to characterize the function of candidate genes such as DFR, LDOX, and FLS in this fascinating case of flower color mimicry.
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Li J, Liang D, Zhang P. Simultaneously collecting coding and non-coding phylogenomic data using homemade full-length cDNA probes, tested by resolving the high-level relationships of Colubridae. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.969581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Resolving intractable phylogenetic relationships often requires simultaneously analyzing a large number of coding and non-coding orthologous loci. To gather both coding and non-coding data, traditional sequence capture methods require custom-designed commercial probes. Here, we present a cost-effective sequence capture method based on homemade probes, to capture thousands of coding and non-coding orthologous loci simultaneously, suitable for all organisms. This approach, called “FLc-Capture,” synthesizes biotinylated full-length cDNAs from mRNA as capture probes, eliminates the need for costly commercial probe design and synthesis. To demonstrate the utility of FLc-Capture, we prepared full-length cDNA probes from mRNA extracted from a common colubrid snake. We performed capture experiments with these homemade cDNA probes and successfully obtained thousands of coding and non-coding genomic loci from 24 Colubridae species and 12 distantly related snake species of other families. The average capture specificity of FLc-Capture across all tested snake species is 35%, similar to the previously published EecSeq method. We constructed two phylogenomic data sets, one including 1,075 coding loci (∼817,000 bp) and the other including 1,948 non-coding loci (∼1,114,000 bp), to study the phylogeny of Colubridae. Both data sets yielded highly similar and well-resolved trees, with 85% of nodes having >95% bootstrap support. Our experimental tests show that FLc-Capture is a flexible, fast, and cost-effective sequence capture approach for simultaneously gathering coding and non-coding phylogenomic data sets to study intractable phylogenetic questions. We hope that this method will serve as a new data collection tool for evolutionary biologists working in the era of phylogenomics.
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Wong DCJ, Peakall R. Orchid Phylotranscriptomics: The Prospects of Repurposing Multi-Tissue Transcriptomes for Phylogenetic Analysis and Beyond. FRONTIERS IN PLANT SCIENCE 2022; 13:910362. [PMID: 35712597 PMCID: PMC9196242 DOI: 10.3389/fpls.2022.910362] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 04/21/2022] [Indexed: 06/10/2023]
Abstract
The Orchidaceae is rivaled only by the Asteraceae as the largest plant family, with the estimated number of species exceeding 25,000 and encompassing more than 700 genera. To gain insights into the mechanisms driving species diversity across both global and local scales, well-supported phylogenies targeting different taxonomic groups and/or geographical regions will be crucial. High-throughput sequencing technologies have revolutionized the field of molecular phylogenetics by simplifying the process of obtaining genome-scale sequence data. Consequently, there has been an explosive growth of such data in public repositories. Here we took advantage of this unprecedented access to transcriptome data from predominantly non-phylogenetic studies to assess if it can be repurposed to gain rapid and accurate phylogenetic insights across the orchids. Exhaustive searches revealed transcriptomic data for more than 100 orchid species spanning 5 subfamilies, 13 tribes, 21 subtribes, and 50 genera that were amendable for exploratory phylotranscriptomic analysis. Next, we performed re-assembly of the transcriptomes before strategic selection of the final samples based on a gene completeness evaluation. Drawing on these data, we report phylogenetic analyses at both deep and shallow evolutionary scales via maximum likelihood and shortcut coalescent species tree methods. In this perspective, we discuss some key outcomes of this study and conclude by highlighting other complementary, albeit rarely explored, insights beyond phylogenetic analysis that repurposed multi-tissue transcriptome can offer.
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A target Capture Probe Set Useful for Deep- and Shallow-Level Phylogenetic Studies in Cactaceae. Genes (Basel) 2022; 13:genes13040707. [PMID: 35456513 PMCID: PMC9032687 DOI: 10.3390/genes13040707] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/10/2022] [Accepted: 04/15/2022] [Indexed: 02/05/2023] Open
Abstract
The molecular phylogenies of Cactaceae have enabled us to better understand their systematics, biogeography, and diversification ages. However, most of the phylogenetic relationships within Cactaceae major groups remain unclear, largely due to the lack of an appropriate set of molecular markers to resolve its contentious relationships. Here, we explored the genome and transcriptome assemblies available for Cactaceae and identified putative orthologous regions shared among lineages of the subfamily Cactoideae. Then we developed a probe set, named Cactaceae591, targeting both coding and noncoding nuclear regions for representatives from the subfamilies Pereskioideae, Opuntioideae, and Cactoideae. We also sampled inter- and intraspecific variation to evaluate the potential of this panel to be used in phylogeographic studies. We retrieved on average of 547 orthologous regions per sample. Targeting noncoding nuclear regions showed to be crucial to resolving inter- and intraspecific relationships. Cactaceae591 covers 13 orthologous genes shared with the Angiosperms353 kit and two plastid regions largely used in Cactaceae studies, enabling the phylogenies generated by our panel to be integrated with angiosperm and Cactaceae phylogenies, using these sequences. We highlighted the importance of using coalescent-based species tree approaches on the Cactaceae591 dataset to infer accurate phylogenetic trees in the presence of extensive incomplete lineage sorting in this family.
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Wong DCJ, Perkins J, Peakall R. Anthocyanin and Flavonol Glycoside Metabolic Pathways Underpin Floral Color Mimicry and Contrast in a Sexually Deceptive Orchid. FRONTIERS IN PLANT SCIENCE 2022; 13:860997. [PMID: 35401591 PMCID: PMC8983864 DOI: 10.3389/fpls.2022.860997] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/17/2022] [Indexed: 06/10/2023]
Abstract
Sexually deceptive plants secure pollination by luring specific male insects as pollinators using a combination of olfactory, visual, and morphological mimicry. Flower color is a key component to this attraction, but its chemical and genetic basis remains poorly understood. Chiloglottis trapeziformis is a sexually deceptive orchid which has predominantly dull green-red flowers except for the central black callus projecting from the labellum lamina. The callus mimics the female of the pollinator and the stark color contrast between the black callus and dull green or red lamina is thought to enhance the visibility of the mimic. The goal of this study was to investigate the chemical composition and genetic regulation of temporal and spatial color patterns leading to visual mimicry, by integrating targeted metabolite profiling and transcriptomic analysis. Even at the very young bud stage, high levels of anthocyanins were detected in the dark callus, with peak accumulation by the mature bud stage. In contrast, anthocyanin levels in the lamina peaked as the buds opened and became reddish-green. Coordinated upregulation of multiple genes, including dihydroflavonol reductase and leucoanthocyanidin dioxygenase, and the downregulation of flavonol synthase genes (FLS) in the callus at the very young bud stage underpins the initial high anthocyanin levels. Conversely, within the lamina, upregulated FLS genes promote flavonol glycoside over anthocyanin production, with the downstream upregulation of flavonoid O-methyltransferase genes further contributing to the accumulation of methylated flavonol glycosides, whose levels peaked in the mature bud stage. Finally, the peak anthocyanin content of the reddish-green lamina of the open flower is underpinned by small increases in gene expression levels and/or differential upregulation in the lamina in select anthocyanin genes while FLS patterns showed little change. Differential expression of candidate genes involved in specific transport, vacuolar acidification, and photosynthetic pathways may also assist in maintaining the distinct callus and contrasting lamina color from the earliest bud stage through to the mature flower. Our findings highlight that flower color in this sexually deceptive orchid is achieved by complex tissue-specific coordinated regulation of genes and biochemical pathways across multiple developmental stages.
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Arifin AR, Reiter NH, May TW, Linde CC. New species of Tulasnella associated with Australian terrestrial orchids in the subtribes Megastylidinae and Thelymitrinae. Mycologia 2022; 114:388-412. [PMID: 35316155 DOI: 10.1080/00275514.2021.2019547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Tulasnella (Tulasnellaceae) is a genus of fungus that can form mycorrhizal associations with orchids (Orchidaceae). Here we used molecular phylogenetic analyses and morphological characteristics of pure cultures across four different media to support the description of five new Tulasnella species associated with commonly occurring and endangered Australian orchids. Tulasnella nerrigaensis associates with Calochilus; T. subasymmetrica and T. kiataensis with Thelymitra; and T. korungensis and T. multinucleata with Pyrorchis and Rimacola respectively. The newly described species were primarily delimited by analyses of five loci: nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS), C14436 (adenosine triphosphate [ATP] synthase), C4102 (glutamate synthase), C3304 (ATP helicase), and mt large subunit 16S rDNA (mtLSU). Tulasnella subasymmetrica is introduced for some isolates previously identified as T. asymmetrica, and this latter species is characterized from multilocus sequencing of a new isolate that matches ITS sequences from the ex-type culture. Morphological differences between the new species are slight. Tulasnella multinucleata has 6-12 nuclei per hyphal compartment which is the first instance of multinucleate rather than binucleate or trinucleate hyphal compartments in Tulasnella. The formal description of these species of Tulasnella will aid in future evolutionary and ecological studies of orchid-fungal interactions.
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Affiliation(s)
- Arild R Arifin
- Ecology and Evolution, Research School of Biology, the Australian National University, ACT 2601, Canberra, Australia
| | - Noushka H Reiter
- Ecology and Evolution, Research School of Biology, the Australian National University, ACT 2601, Canberra, Australia.,Science Division, Royal Botanic Gardens Victoria, cnr Ballarto Road and Botanic Drive, Cranbourne, 3977, Australia
| | - Tom W May
- Science Division, Royal Botanic Gardens Victoria, Melbourne, 3004, Australia
| | - Celeste C Linde
- Ecology and Evolution, Research School of Biology, the Australian National University, ACT 2601, Canberra, Australia
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