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At least 19 recordsLinked to original sources
PubMed1994

Characterization and molecular cloning of mannose-binding lectins from the Orchidaceae species Listera ovata, Epipactis helleborine and Cymbidium hybrid.

Mannose-binding lectins were purified from the leaves of three Orchidaceae species, namely Listera ovata (twayblade), Epipactis helleborine (broad-leaved helleborine) and Cymbidium hybrid, using affinity chromatography on Mannose - Sepharose-4B. Apparently, the Orchidaceae lectins are dimeric proteins composed of lectin subunits of 12-13 kDa. All of the isolated lectins exhibit exclusive specificity towards mannose. A cDNA library constructed from poly(A) rich RNA isolated from leaves of L. ovata was screened for cDNA clones encoding the lectin using colony hybridization. Since N-terminal sequence analysis of the twayblade lectin revealed some sequence similarity to the previously cloned mannose-binding lectin Hippeastrum hybrid (amaryllis) ovaries, the amaryllis lectin cDNA clone was used as a probe to screen the L. ovata library. Subsequently, the cDNA clone encoding the L. ovata lectin was used to screen the cDNA libraries from the taxonomically related orchid species Cymbidium hybrid and E. helleborine. Sequence analysis of the lectin cDNA clones from different Orchidaceae species revealed approximately 50% sequence similarity both at the nucleotide and amino acid level. The Orchidaceae lectins are apparently translated from mRNAs consisting of approximately 800 nucleotides. The primary translation products are preproproteins which are converted into the mature lectins following post-translational modifications. Southern blot analysis of genomic DNA has shown that the lectins are most probably encoded by a family of closely related genes which is in good agreement with the sequence heterogeneity found between different lectin cDNA clones of one species.

Agglutination Tests↗
PubMed2004

Utility of plastid psaB gene sequences for investigating intrafamilial relationships within Orchidaceae.

DNA sequences of the plastid gene psaB were completed for 182 species of Orchidaceae (representing 150 different genera) and outgroup families in Asparagales. These data were analyzed using parsimony, and resulting trees were compared to a rbcL phylogeny of Orchidaceae for the same set of taxa after an additional 30 new rbcL sequences were added to a previously published matrix. The psaB tree topology is similar to the rbcL tree, although the psaB data contain less homoplasy and provide greater bootstrap support than rbcL alone. In combination, the two-gene tree recovers the five monophyletic subfamilial clades currently recognized in Orchidaceae, but fails to resolve the positions of Cypripedioideae and Vanilloideae. These new topologies help to clarify some of the anomalous results recovered when rbcL is analyzed alone. Both genes appear to be absent from the plastid genome of several achlorophyllous orchids, but are present in the form of presumably non-functional pseudogenes in Cyrtosia. This study is the first to document the utility of psaB sequences for phylogenetic studies of plants below the family level.

Base Sequence↗
PubMed2004

Molecular identification of mycorrhizal fungi in Neuwiedia veratrifolia (Orchidaceae).

We here apply a previously described method for identification of single peloton orchid mycorrhiza to a key orchid group and extend the usefulness in the heterobasidiomycetes of an existing fungal database for identification of mycorrhizal fungi. We amplified and sequenced mitochondrial ribosomal large subunit DNA from fungi in roots of Neuwiedia veratrifolia (Orchidaceae), a member of the small subfamily Apostasioideae that is sister to the remainder of Orchidaceae, and used the extended database to identify the mycorrhizal fungi. Sequences from fungi cultured from Neuwiedia roots and from direct peloton amplifications were analyzed cladistically with sequences determined from reference fungal collections and published sequences. The fungi from Neuwiedia are referred to the heterobasidiomycetous orders Tulasnellales and Ceratobasidiales, indicating that apostasioids utilize the same fungi as other photosynthetic orchids. The majority of Neuwiedia mycobionts came together in a clade with Tulasnella species, but some were most closely related to Thanatephorus. In some cases members of these two clades were isolated from the same orchid plant, providing another example of multiple mycobionts occurring in a single plant.

Basidiomycota↗
PubMed2005

[Studies on chemical components and pharmacological activities of geobiontic type medicinal plants in Orchidaceae family].

Geobiontic type medicinal plants subjected to Orchidaceae family are used as important traditional Chinese medicine. Scientists are paying more attentions to their chemical components and pharmacology recently. This paper reviewed their chemical components involved in phenanthrene, bibenzene, flavone, sterol, terpenes, alkoloids and pharmacology such as antibacterium, cytotoxic activity, antihyperliposis effects. All these information are beneficial to reveal the relative among these medicinal plants in Orchidaceae family and are helpful to develop new drugs.

Alkaloids↗
PubMed2001

Fly-pollinated Pleurothallis (Orchidaceae) species have high genetic variability: evidence from isozyme markers.

We conducted an isozyme study in 22 populations of five Pleurothallis (Orchidaceae) species (12 loci in nine enzymatic systems). The genetic variability in all populations is surprisingly high (P = 58-83%, A = 2.1-3.8, H(e) = 0.25-0.43) in spite of the fact that the five species are pollinated by small flies whose behavior enables self-pollination. We suggest that self-incompatibility, inbreeding depression, and mechanical barriers that prevent self-pollination in these species are responsible for the maintainance of the high genetic variability. These traits are uncommon in Orchidaceae, but have been observed in these and some other species pollinated by flies or other pollinators with behavior that facilitates self-pollination. The genetic similarity among conspecific populations is also high for species with very short-range flying pollinators. Only one population of P. teres presented values of genetic similarity lower than usually observed in allopatric conspecific populations. Morphology, however, does not support its segregation as a new taxon. All species can be recognized by their enzymatic patterns, and the results agree with recently proposed taxonomic realignments. Conversely, the supposed affinities among these species based on floral morphology are not supported, and we hypothesize that it may be due to convergence in species with similar pollinators.

Journal Article↗
PubMed2002

Notes on the pollination biology of Notylia nemorosa (Orchidaceae): do pollinators necessarily promote cross pollination?

The pollination biology of Notylia nemorosa was elucidated from field and ex situ observations. Field observations were carried out in Minas Gerais, southeastern Brazil, where this orchid is pollinated by males of Eulaema nigrita(Euglossini). Plants cultivated in Campinas (São Paulo State, southeastern Brazil) were eventually pollinated by males of Eulaema nigrita and Euglossa melanothricha(Euglossini). In both cases, Euglossini males collect aromatic compounds produced on the surface of the lip, fix the pollinaria on the dorsal surface of the labrum and perform pollination. This species is protandrous. Recently opened flowers present their stigmatic surfaces blocked and thus flowers act only as pollen donors. After 2-3 days the viscidium dries out and pollinaria cannot be removed anymore. Then, a narrow slit opens in the stigmatic cavity, allowing pollen deposition. Experiments performed with cultivated plants suggest that this orchid species is strongly, though not completely self-incompatible. Pollination experiments showed that bees tend to stay several minutes in each inflorescence. This behavior may promote some degree of geitonogamous pollination because flowers in male and female phases coexist in the same inflorescence. The combination of self-incompatibility with this specific pollinator behavior may explain the rarity of fruits in several neotropical reward-offering Orchidaceae.

Animals↗
PubMed2005

Molecular phylogenetics of subtribe Aeridinae (Orchidaceae): insights from plastid matK and nuclear ribosomal ITS sequences.

We conducted phylogenetic analyses using two DNA sequence data sets derived from matK, the maturase-coding gene located in an intron of the plastid gene trnK, and the internal transcribed spacer region of 18S-26S nuclear ribosomal DNA to examine relationships in subtribe Aeridinae (Orchidaceae). Specifically, we investigated (1) phylogenetic relationships among genera in the subtribe, (2) the congruence between previous classifications of the subtribe and the phylogenetic relationships inferred from the molecular data, and (3) evolutionary trends of taxonomically important characters of the subtribe, such as pollinia, a spurred lip, and a column foot. In all, 75 species representing 62 genera in subtribe Aeridinae were examined. Our analyses provided the following insights: (1) monophyly of subtribe Aeridinae was tentatively supported in which 14 subclades reflecting phylogenetic relationships can be recognized, (2) results are inconsistent with previous classifications of the subtribe, and (3) repeated evolution of previously emphasized characters such as pollinia number and apertures, length of spur, and column foot was confirmed. It was found that the inconsistencies are mainly caused by homoplasy of these characters. At the genus level, Phalaenopsis, Cleisostoma, and Sarcochilus are shown to be non-monophyletic.

Base Sequence↗
PubMed2003

Plastid DNA variation in the Dactylorhiza incarnata/maculata polyploid complex and the origin of allotetraploid D. sphagnicola (Orchidaceae).

To obtain further information on the polyploid dynamics of the the Dactylorhiza incarnata/maculata polyploid complex and the origin of the allotetraploid D. sphagnicola (Orchidaceae), plastid DNA variation was studied in 400 plants from from Sweden and elsewhere in Europe and Asia Minor by means of polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) and sequencing. Allotetraploid taxa in Europe are known have evolved by multiple independent polyploidization events following hybridization between the same set of two distinct ancestral lineages. Most allotetraploids have inherited the plastid genome from parents similar to D. maculata sensu lato, which includes, e.g. the diploid D. fuchsii and the autotetraploid D. maculata sensu stricto. D. sphagnicola carries a separate plastid haplotype different from the one found in other allotetraploid taxa, which is in agreement with an independent origin from the parental lineages. Some of the remaining allotetraploids have local distributions and appear to be of postglacial origin, whereas still other allotetraploids may be of higher age, carrying plastid haplotypes that have not been encountered in present day representatives of the parental lineages. Introgression and hybridization between diploids and allotetraploids, and between different independently derived allotetraploids may further have contributed to genetic diversity at the tetraploid level. Overall, the Dactylorhiza polyploid complex illustrates how taxon diversity and genetic diversity may be replenished rapidly in a recently glaciated area.

Base Sequence↗
PubMed2003

Fine-scale phylogeographical analysis of Mediterranean Anacamptis palustris (Orchidaceae) populations based on chloroplast minisatellite and microsatellite variation.

The phylogeographical history of the rare marsh orchid Anacamptis palustris (Orchidaceae) was reconstructed using highly polymorphic chloroplast minisatellite and microsatellite loci. Allelic variation at chloroplast microsatellite loci was due to length variation in poly(A/T) repeats and was informative on a regional scale, but was not sufficient to unravel relationships among populations on a local geographical scale. The minisatellite locus, however, was found to be highly variable. Nine distinct repeat types were found and variation in repeat number occurred in five repeat types. The distribution of chloroplast haplotypes, combining microsatellite and minisatellite repeat type variation, provided a clear phylogeographical picture on a large geographical scale, whereas length variation in one highly polymorphic minisatellite repeat type provided fine-scale phylogeographical information. Mediterranean populations could be divided into four main lineages, a western European lineage, a northern and central Italian lineage, a well-isolated southern Italian (Apulian) lineage, and an eastern European lineage. Variation at the most variable minisatellite repeat type N revealed 19 alleles and allowed the study of seed-mediated gene flow and an estimation of the ratio of pollen to seed flow among neighbouring populations.

Base Sequence↗
PubMed2002

Floral and vegetative morphometrics of five Pleurothallis (Orchidaceae) species: correlation with taxonomy, phylogeny, genetic variability and pollination systems.

Morphometric analyses of vegetative and floral characters were conducted in 21 populations of five Pleurothallis (Orchidaceae) species occurring in Brazilian 'campo rupestre' vegetation. A phylogenetic analysis of this species group was also carried out using nuclear ribosomal DNA internal transcribed spacers (ITS1 and ITS2). Results of the ordination and cluster analyses agree with species' delimitation revealed by taxonomic and allozyme studies. The groups formed in ordination analysis correspond to the pollinator groups determined in a previous pollination study. Relationships among the species in the cluster analysis using only vegetative characters are similar to those found in a previous allozyme study, but those indicated by cluster analysis using only floral characters differ. These results support the hypothesis that floral similarities are due to convergence driven by similar pollination mechanisms, and therefore floral traits may not be good indicators of phylogenetic relationships in this group. The results of the phylogenetic analysis support this conclusion to some extent. There is no correlation between genetic (allozyme) and morphological variability in the populations nor in the way this variability is distributed among conspecific populations. We describe a new subspecies of Pleurothallis ochreata based on differences in vegetative and chemical characters as well as geographic distribution. Absence of differentiation in floral characters, attraction of the same pollinator species, interfertility and genetic similarity support the argument for subspecific rather than specific status.

Brazil↗
PubMed2005

Life history evolution and genome size in subtribe Oncidiinae (Orchidaceae).

BACKGROUND AND AIMS: Within Oncidiinae, there are several groups of species that are effectively annuals, and we wished to see if these species had smaller genome sizes than average for the subtribe. METHODS: Fifty-four genome size estimates (50 of which are new) for species in subtribe Oncidiinae (Orchidaceae) were examined for the first time in a phylogenetic context to evaluate hypotheses concerning genome sizes and life history traits. RESULTS AND CONCLUSIONS: Within the limits of still relatively sparse sampling, the species that are effectively annuals do appear to have smaller genome sizes than average. However, the genome sizes of their immediate sister group are also small, indicating that changes in genome size preceded the change in life history traits. Genome sizes and chromosome numbers also do not correlate; some slowly growing species have lower chromosome numbers but large genomes and vice versa. Based on a survey of the literature on orchids, it is also clear that epiphytic species have smaller genome sizes than do terrestrial species, which could be an effect of different water relations or the fact that most terrestrial orchids are geophytic or have distinct growth and dormancy phases.

Evolution, Molecular↗
PubMed2006

Low genetic structure in an epiphytic Orchidaceae (Oncidium hookeri) in the Atlantic rainforest of South-eastern Brazil.

BACKGROUND AND AIMS: Oncidium hookeri is a neotropical species of epiphytic Orchidaceae found in the Brazilian Atlantic rainforest at the top of the Mantiqueira Range of mountains. The genetic variation of O. hookeri was studied to assess the distribution of genetic variability within and among six populations localized in Atlantic rainforest remnants. Gene flow among populations and the occurrence of recent bottlenecks were investigated in order to infer the degree of isolation of these populations. METHODS: Thirteen polymorphic loci were used for allozyme electrophoresis. The data were analysed by means of standard statistical approaches, to estimate gene diversity and the genetic structure of the populations. KEY RESULTS: The mean gene diversity and allelic richness were H(e) = 0.099 and A = 1.75, respectively. F-statistics revealed high heterozygote deficiencies in all populations (F(IS) = 0.43-0.82). Several rare alleles were found in all the populations, and three populations presented private alleles. Low genetic differentiation among O. hookeri populations was detected (F(ST) = 0.029); natural selection may be involved in PGM locus differentiation among populations. The genetic differentiation between paired populations was low, bearing no correlation with geographic distance (Mantel test: r = -0.34, P = 0.72). Only two populations showed signs of recent bottlenecks. CONCLUSIONS: The heterozygote deficiency found seems to be caused by pollinator behaviour; the low frequencies of several alleles of different loci can be maintained due to clonal propagation. Despite the stochastic nature of the wind-dispersal of seeds to long distances, this process may promote an effective gene flow among populations, thus avoiding genetic differentiation.

Brazil↗
PubMed2025

Unequally Abundant Chromosomes and Unusual Collections of Transferred Sequences Characterize Mitochondrial Genomes of Gastrodia (Orchidaceae), One of the Largest Mycoheterotrophic Plant Genera.

The mystery of genomic alternations in heterotrophic plants is among the most intriguing in evolutionary biology. Compared to plastid genomes (plastomes) with parallel size reduction and gene loss, mitochondrial genome (mitogenome) variation in heterotrophic plants remains underexplored in many aspects. To further unravel the evolutionary outcomes of heterotrophy, we present a comparative mitogenomic study with 13 de novo assemblies of Gastrodia (Orchidaceae), one of the largest fully mycoheterotrophic plant genera, and its relatives. Analyzed Gastrodia mitogenomes range from 0.56 to 2.1 Mb, each consisting of numerous, unequally abundant chromosomes or contigs. Size variation might have evolved through chromosome rearrangements followed by stochastic loss of "dispensable" chromosomes, with deletion-biased mutations. The discovery of a hyper-abundant (∼15 times intragenomic average) chromosome in two assemblies represents the hitherto most extreme copy number variation in any mitogenomes, with similar architectures discovered in two metazoan lineages. Transferred sequence contents highlight asymmetric evolutionary consequences of heterotrophy: despite drastically reduced intracellular plastome transfers convergent across heterotrophic plants, their rarity of horizontally acquired sequences sharply contrasts parasitic plants, where massive transfers from their hosts prevail. Rates of sequence evolution are markedly elevated but not explained by copy number variation, extending prior findings of accelerated molecular evolution from parasitic to heterotrophic plants. Putative evolutionary scenarios for these mitogenomic convergence and divergence fit well with the common (e.g. plastome contraction) and specific (e.g. host identity) aspects of the two heterotrophic types. These idiosyncratic mycoheterotrophs expand known architectural variability of plant mitogenomes and provide mechanistic insights into their content and size variation.

Genome, Mitochondrial↗
PubMed2003

Gene flow across species boundaries in sympatric, sexually deceptive Ophrys (Orchidaceae) species.

Orchids of the genus Ophrys (Orchidaceae) are pollinated by male bees and wasps through sexual deception. The Ophrys sphegodes group encompasses several closely related species that differ slightly in floral morphology and are pollinated by different solitary bee species. Populations representing different species of the O. sphegodes group often flower simultaneously in sympatry. To test whether gene flow across the species boundaries occurs in these sympatric populations, or whether they are reproductively isolated, we examined the distribution of genetic variation within and among populations and species of this group. We collected at each of five different localities in southern France and Italy two sympatric, co-flowering Ophrys populations, representing six Ophrys species in total. The six microsatellite loci surveyed were highly variable. Genetic differentiation among geographically distant populations of the same species was lower than differentiation among sympatric populations of different species. However, the strength of genetic differentiation among species was among the lowest reported for orchids. Genotype assignment tests and marker-based estimates of gene flow revealed that gene flow across species boundaries occurred and may account for the low observed differentiation among species. These results suggest that sexual deceit pollination in Ophrys may be less specific than thought, or that rare mistakes occur.

Cluster Analysis↗
PubMed2005

Phylogeography of pollinator-specific sexually deceptive Chiloglottis taxa (Orchidaceae): evidence for sympatric divergence?

Divergence in sexually deceptive orchids is thought to occur through shifts in the attraction of specific pollinators, a process that is mediated by changes in the floral odours that lure sexually excited male insects. We investigated the origin of reproductive isolation in a sexually deceptive species complex of Chiloglottis R.Br. (Orchidaceae: Diurideae). Two geographically separated montane regions in eastern Australia were sampled, each containing sympatric pairs of orchid taxa presently found under the name, Chiloglottis pluricallata. Behavioural tests confirmed at least three distinct orchid taxa that specifically attract different pollinators. An artificial crossing experiment among two taxa from one region demonstrated their interfertility, and confirmed isolation to be a function of pollinator attraction. A phylogeographic analysis using amplified fragment length polymorphisms (AFLPs) indicated that samples from each geographical region are most closely related, a pattern consistent with in situ or sympatric divergence. However, an extensive population genetic study on two taxa from one region failed to entirely reject the possibility of intertaxon gene flow. Although clear genetic differentiation of the taxa is evident in two out of three sites where both grow in direct sympatry, overall, the two taxa are not strongly distinguished by AFLP markers. The reconstruction of a simple bifurcating pattern of divergence may be confounded by a combination of contemporary population-level processes operating within each taxon, the retention of ancestral polymorphism or intertaxon gene flow.

Alleles↗
PubMed2004

Systemic endopolyploidy in Spathoglottis plicata (Orchidaceae) development.

BACKGROUND: Endopolyploidy is developmentally regulated. Presence of endopolyploidy as a result of endoreduplication has been characterized in insects, mammals and plants. The family Orchidaceae is the largest among the flowering plants. Many of the members of the orchid family are commercially micropropagated. Very little has been done to characterize the ploidy variation in different tissues of the orchid plants during development. RESULTS: The DNA contents and ploidy level of nuclei extracted from various tissues of a tropical terrestrial orchid Spathoglottis plicata were examined by flow cytometry. Sepals, petals and ovary tissues were found to have only a 2C (C, DNA content of the unreplicated haploid chromosome complement) peak. Columns, floral pedicels of newly open flowers and growing flower stems were observed to have an endopolyploid 8C peak in addition to 2C and 4C peaks. In developing floral pedicels, four peaks were observed for 2C, 4C, 8C and 16C. In root tips, there were 2C, 4C and 8C peaks. But in the root tissues at the region with root hairs, only a 2C peak was observed. Nuclei extracted from young leaves shown three peaks for 2C, 4C and 8C. A similar pattern was found in the vegetative tissues of both greenhouse-grown plants and tissue-cultured plantlets. In mature leaves, a different pattern of ploidy level was found at different parts of the leaves. In the leaf tips and middle parts, there were 2C and 4C peaks. Only at the basal part of the leaves, there were three peaks for 2C, 4C and 8C. CONCLUSIONS: Systemic variation of cellular endopolyploidy in different tissues during growth and development of Spathoglottis plicata from field-grown plants and in vitro cultures was identified. The implication of the findings was discussed.

Cell Nucleus↗
PubMed2004

Ants visit nectaries of Epidendrum denticulatum (Orchidaceae) in a Brazilian rainforest: effects on herbivory and pollination.

Epidendrum denticulatum (Orchidaceae) produces nectar on the petioles of buds, flowers, and fruits (extrafloral nectaries) but no nectar is found on its flowers, and it is probably a deceptive species. In the Brazilian Atlantic rainforest, some aspects of both the ecology and behavior of Camponotus sericeiventris (Formicinae) and Ectatomma tuberculatum (Ponerinae), two ant species foraging on E. denticulatum extrafloral nectaries, were investigated. Both experiments, using termites as baits and field observations, suggest that these ant species are able to prevent reproductive organ herbivory, without affecting pollinator behaviour. Since a low fruit set is often cited as a characteristic of the family, especially for deceptive species, ants attracted to orchid inflorescences protect reproductive structures and increase the probability of pollination success. Epidendrum denticulatum flowers were visited and probably pollinated by Heliconius erato (Nymphalidae) and Euphyes leptosema (Hesperiidae).

Animals↗
PubMed1999

[Studies on the plant hormones produced by 5 species of endophytic fungi isolated from medicinal plants (Orchidacea)].

OBJECTIVE: To study the plant hormones produced by 5 species of endophytic fungi isolated from medicinal plants and to illustrate the mechanism on endophytic fungi stimulating the growth of plants. METHODS: Extracting plant hormones from mycelia and its culture solution with organic solvent, and detecting them by HPLC. RESULTS: One or more plant hormones [GA3 (Gibberellin), IAA (Indoleacetic acid), ABA (Abscisic acid), Z (Zeatin), ZR (Zeatin riboside)] were detected from the mycelia and its culture solution. CONCLUSIONS: The plant hormones produced by the endophytic fungi are important materials that may be used to reveal the mechanism of endophytic fungi stimulating the growth of medicinal plants (Orchidacea).

Abscisic Acid↗