Molecular phylogenetic analyses reveal multiple long-distance dispersal events and extensive cryptic speciation in Nervilia (Orchidaceae), an isolated basal Epidendroid genus

Frontiers in Plant Science, Journal Year: 2025, Volume and Issue: 15

Published: Feb. 20, 2025

Introduction The terrestrial orchid genus Nervilia is diagnosed by its hysteranthous pattern of emergence but nested among leafless myco-heterotrophic lineages in the lower Epidendroideae. Comprising ca. 80 species distributed across Africa, Asia and Oceania, remains poorly known plagued vague overlapping circumscriptions, especially within each a series taxonomically intractable complexes. Prior small-scale, exploratory molecular phylogenetic analyses have revealed existence cryptic species, little otherwise understood origin, scale timing biogeographic spread, or palaeoclimatic factors that shaped ecology given rise to contemporary patterns occurrence. Methods Here, we sample widely throughout generic range, including 45 named taxa multiple accessions referable several widespread ‘macrospecies’, as well material equivocal identity probable undescribed status, for first time enabling an evaluation taxonomic boundaries at both sectional level. Using nuclear ( ITS ) plastid matK , trnL-F sequence data, conduct (maximum parsimony Bayesian inference) ancestral area analysis infer relationships resolve origin colonisation routes. Results strongly supported monophyletic, are three sections. However, number flowers inflorescence other floral characters poor indicators affinity. Dated supports Africa Early Oligocene, with spread eastwards occurring Late Miocene, plausibly via Gomphotherium land bridge when it woodland savanna ecosystems. Discussion Taxonomic radiation last 8 million years ties dramatic Himalayan-Tibetan Plateau uplift associated intensification monsoon. Multiple long-range migrations appear occurred thereafter, colonised Malesia Oceania from Pliocene onwards. bulk diversity relatively recent, potentially explaining ubiquity speciation, which leaves numerous overlooked unnamed. Widespread disjunct pairs hint high mobility continents, extinction history climate-induced vicariance. Persistent challenges highlighted.

Language: Английский

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At the core of the endomycorrhizal symbioses: intracellular fungal structures in orchid and arbuscular mycorrhiza

New Phytologist, Journal Year: 2023, Volume and Issue: 242(4), P. 1408 - 1416

Published: Oct. 26, 2023

Summary Arbuscular (AM) and orchid (OrM) mycorrhiza are the most widespread mycorrhizal symbioses among flowering plants, formed by distinct fungal plant species. They both endosymbioses because hyphae can enter inside cell to develop intracellular structures that surrounded membrane. The symbiotic plant–fungus interface is considered be major site of nutrient transfer host plant. We summarize recent data on in OrM compare development function arbuscules AM pelotons order outline differences conserved traits. further describe unexpected similarities form observed orchids roots mycoheterotrophic plants forming AM. speculate these may result convergent evolution types highlight knowledge gaps new research directions explore this scenario.

Language: Английский

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Organelle Genomes of Epipogium roseum Provide Insight into the Evolution of Mycoheterotrophic Orchids

International Journal of Molecular Sciences, Journal Year: 2024, Volume and Issue: 25(3), P. 1578 - 1578

Published: Jan. 27, 2024

Epipogium roseum, commonly known as one of the ghost orchids due to its rarity and almost transparent color, is a non-photosynthetic fully mycoheterotrophic plant. Given special nutritional strategies evolutionary significance, mitogenome was first characterized, three plastomes sampled from Asia were assembled. The found be smallest among Orchidaceae, with lengths ranging 18,339 19,047 bp, exhibited high sequence variety. For mitogenome, total 414,552 bp in length, comprising 26 circular chromosomes, identified. A 54 genes, including 38 protein-coding 13 tRNA 3 rRNA annotated. Multiple repeat sequences spanning length 203,423 (45.47%) discovered. Intriguingly, six plastid regions via intracellular gene transfer four horizontal observed. phylogenomics, incorporating 90 56 mitogenomes, consistently revealed sister relationship Gastrodia, bootstrap percentage 100%. These findings shed light on organelle evolution Orchidaceae plants.

Language: Английский

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Diploid and tetraploid genomes of Acorus and the evolution of monocots

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: June 20, 2023

Abstract Monocots are a major taxon within flowering plants, have unique morphological traits, and show an extraordinary diversity in lifestyle. To improve our understanding of monocot origin evolution, we generate chromosome-level reference genomes the diploid Acorus gramineus tetraploid Ac. calamus , only two accepted species from family Acoraceae, which form sister lineage to all other monocots. Comparing suggest that is not potential progenitor allotetraploid with subgenomes A, B, presenting asymmetric evolution B subgenome dominance. Both genome A clear evidence whole-genome duplication (WGD), but Acoraceae does seem share older WGD shared by most We reconstruct ancestral karyotype gene toolkit, discuss scenarios explain complex history genome. Our analyses ancestors monocots exhibit mosaic genomic features, likely important for appeared early providing fundamental insights into origin, diversification

Language: Английский

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Genome of the early spider-orchid Ophrys sphegodes provides insights into sexual deception and pollinator adaptation

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: July 26, 2024

Abstract Pollinator-driven evolution of floral traits is thought to be a major driver angiosperm speciation and diversification. Ophrys orchids mimic female insects lure male pollinators into pseudocopulation. This strategy, called sexual deception, species-specific, thereby providing strong premating reproductive isolation. Identifying the genomic architecture underlying pollinator adaptation may shed light on mechanisms Here, we report 5.2 Gb chromosome-scale genome sequence sphegodes . We find evidence for transposable element expansion that preceded radiation O. group, gene duplication having contributed chemical mimicry. highly differentiated candidate region pollinator-mediated chromosome 2. The will prove useful investigations repeated architectures facilitate evolutionary radiations.

Language: Английский

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Probiotic model for studying rhizosphere interactions of root exudates and the functional microbiome

The ISME Journal, Journal Year: 2024, Volume and Issue: 18(1)

Published: Jan. 1, 2024

Abstract Root exudates are important mediators of plant–microbiome interactions. Recent pioneering studies on various aerial root plants, including cereals, have shown that carbohydrate-rich mucilage can enrich diazotrophs and increase host nitrogen utilization growth. Moreover, non-diazotrophic “gatekeeper” microorganisms in help defend against pathogenic environmental microbes. These findings highlight the active role mediating interactions to maintain microbial homeostasis rhizosphere. However, little is known about specific mechanisms by which modulate functional microbiome rhizosphere microhabitats. Here, we propose typical stable biointeractions four plant–specific mucilage–probiotic systems as a model for understanding exudate–functional interaction. We anticipate this provide fundamental biological insights into

Language: Английский

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Genome-wide identification and expression analysis of the GRAS gene family in Dendrobium chrysotoxum

Frontiers in Plant Science, Journal Year: 2022, Volume and Issue: 13

Published: Nov. 28, 2022

The GRAS gene family encodes transcription factors that participate in plant growth and development phases. They are crucial regulating light signal transduction, hormone (e.g. gibberellin) signaling, meristem growth, root radial development, response to abiotic stress, etc. However, little is known about the features functions of genes Orchidaceae, largest most diverse angiosperm lineage. In this study, genome-wide analysis was conducted Dendrobium chrysotoxum (Epidendroideae, Orchidaceae) investigate its physicochemical properties, phylogenetic relationships, structure, expression patterns under stress orchids. Forty-six DchGRAS were identified from D. genome divided into ten subfamilies according their relationships. Sequence showed proteins contained conserved VHIID SAW domains. Gene structure intronless accounted for approximately 70% genes, structures same subfamily same, motifs also similar. K a/ s ratios 12 pairs all less than 1, indicating underwent negative selection. results cis -acting element 46 a large number hormone-regulated light-responsive elements as well environmental stress-related elements. addition, real-time reverse quantitative PCR (RT−qPCR) experimental significant differences levels high temperature, drought salt treatment, among which two members LISCL ( DchGRAS13 DchGRAS15 ) sensitive stress. Taken together, paper provides insights regulatory roles

Language: Английский

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Genome-wide analysis of the TCP gene family and their expression pattern in Cymbidium goeringii

Frontiers in Plant Science, Journal Year: 2022, Volume and Issue: 13

Published: Dec. 8, 2022

TCP gene family are specific transcription factors for plant, and considered to play an important role in development growth. However, few related studies investigated the trait how it plays a growth of Orchidaceae. In this study, we obtained 14 genes ( CgTCPs ) from Spring Orchid Cymbidium goeringii genome. The classification results showed that were mainly divided into two clades as follows: four PCF (Class I), nine CIN one CYC II). sequence analysis proteins C. contain conserved regions (basic Helix-Loop-Helix) domain. exon−intron structure varied clade according comparative investigation structure, some had no introns. There fewer CgTCP homologous pairs compared with Dendrobium catenatum Phalaenopsis equestris , suggesting suffered more loss events. majority cis -elements revealed be enriched function light responsiveness, followed by MeJA ABA demonstrating their functions regulating phytohormones. collinearity study TCPs D. P. almost 1:1. transcriptomic data real-time reverse transcription-quantitative PCR (RT−qPCR) expression profiles flower-specific class II CgCIN2 CgCIN5 CgCIN6 may regulation florescence. Altogether, provides comprehensive uncovering underlying

Language: Английский

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Orchids acquire fungal carbon for seed germination: pathways and players

Trends in Plant Science, Journal Year: 2024, Volume and Issue: 29(7), P. 733 - 741

Published: Feb. 29, 2024

Language: Английский

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The road less taken: Dihydroflavonol 4‐reductase inactivation and delphinidin anthocyanin loss underpins a natural intraspecific flower colour variation

Molecular Ecology, Journal Year: 2024, Volume and Issue: unknown

Published: April 23, 2024

Abstract Visual cues are of critical importance for the attraction animal pollinators, however, little is known about 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 to investigate a bee‐pollinated orchid species, Glossodia major with common purple‐ infrequent white‐flowered morphs. We found uncommon previously unreported delphinidin‐based anthocyanins responsible conspicuous pollinator‐perceivable purple morph three genetic changes loss in white – (1) loss‐of‐function (LOF; frameshift) mutation affecting dihydroflavonol 4‐reductase ( DFR1 ) coding due unique 4‐bp insertion, (2) specific downregulation expression (3) unexpected discovery chimeric Gypsy transposable element (TE)‐gene DFR transcripts potential consequences genomic stability post‐transcriptional or epigenetic regulation . This one few cases where regulatory LOF an anthocyanin structural gene, rather than transcription factors, important. Furthermore, if TEs prove be frequent source mutation, interplay between environmental stress‐induced TE evolution pollinator‐mediated selection adaptive variation may overlooked mechanism maintaining polymorphism nature.

Language: Английский

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