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At least 19 recordsLinked to original sources
PubMed1999

Effect of bracken (Pteridium a quilinum) and dryopteris (Dryopteris juxtaposita) fern toxicity in laboratory rabbits.

Experimental studies with Bracken and Dryopteris ferns @ 25% concentrate ration mixture were conducted in rabbits. Fern fed rabbits showed progressive anaemia, leukopaenia, lymphopaenia and relative heterophilia. Significant elevations in serum enzymes like serum glutamate oxaloactate transminase (SGOT), serum glutamate pyruvate transminase (SGPT), alkaline phosphatase (ALP), urea and creatinine levels were seen. Histopathologically, rabbits showed mild to moderate vascular changes in most of visceral organs, vacuolar degenerative changes in hepatocytes, hypersecretory activity in intestine, presence of casts in renal tubules and degenerative changes in renal tubular lining epithelial cells. Dryopteris fed rabbits showed somewhat more severe degenerative and vascular changes in different intervals. A low level of toxic principle ptaquiloside was detected in Bracken and Dryopteris ferns by thin layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) methods.

Animals↗
PubMed2006

Phylogenetics of Chinese Dryopteris (Dryopteridaceae) based on the chloroplast rps4-trnS sequence data.

Dryopteris is one of the largest and most taxonomically complex fern genera in the Dryopteridaceae, with 127 species occurring throughout temperate, sub-temperate, subtropical, and tropical China. Investigations of the evolutionary relationships of a subset of these Chinese Dryopteris species, using DNA sequence-based methods, specifically tested the monophyly of the genus and the validity of the previous subgeneric classifications. Sixty species of Dryopteris, four closely related non-Dryopteris and three species of Arachniodes, were used as outgroup taxa. The rps4-trnS region of the chloroplast genome was sequenced in these species for the first time. Both maximum parsimony (MP) and neighbor-joining (NJ) analyses identified six polyphyletic clades that contained Dryopteris species. These results were supported by a Bayesian analysis of the same data set. The phylogenetic patterns strongly suggest the polyphyletic status of Dryopteris; the monophyletic groupings of the species do not correspond with either Fraser-Jenkins [In: Bull Brit Mus (Nat Hist) Bot 14(3):183-218, 1986} or Wu (In: Flora Reipublica Popularis Sinicae Tomus 5 (1) pp 1-241, 2000] subgeneric classification of Dryopteris, except in a few specific cases. This work represents the first molecular systematic analyses of Chinese Dryopteris, and we propose the next steps necessary to recognize new subgenera of the genus.

Base Sequence↗
PubMed1999

The structure and unusual pH dependence of plastocyanin from the fern Dryopteris crassirhizoma. The protonation of an active site histidine is hindered by pi-pi interactions.

Spectroscopic properties, amino acid sequence, electron transfer kinetics, and crystal structures of the oxidized (at 1.7 A resolution) and reduced form (at 1.8 A resolution) of a novel plastocyanin from the fern Dryopteris crassirhizoma are presented. Kinetic studies show that the reduced form of Dryopteris plastocyanin remains redox-active at low pH, under conditions where the oxidation of the reduced form of other plastocyanins is inhibited by the protonation of a solvent-exposed active site residue, His87 (equivalent to His90 in Dryopteris plastocyanin). The x-ray crystal structure analysis of Dryopteris plastocyanin reveals pi-pi stacking between Phe12 and His90, suggesting that the active site is uniquely protected against inactivation. Like higher plant plastocyanins, Dryopteris plastocyanin has an acidic patch, but this patch is located closer to the solvent-exposed active site His residue, and the total number of acidic residues is smaller. In the reactions of Dryopteris plastocyanin with inorganic redox reagents, the acidic patch (the "remote" site) and the hydrophobic patch surrounding His90 (the "adjacent" site) are equally efficient for electron transfer. These results indicate the significance of the lack of protonation at the active site of Dryopteris plastocyanin, the equivalence of the two electron transfer sites in this protein, and a possibility of obtaining a novel insight into the photosynthetic electron transfer system of the first vascular plant fern, including its molecular evolutionary aspects. This is the first report on the characterization of plastocyanin and the first three-dimensional protein structure from fern plant.

Amino Acid Sequence↗
PubMed2004

Molecular phylogenetics and historical biogeography of Hawaiian Dryopteris (Dryopteridaceae).

The fern genus Dryopteris (Dryopteridaceae) is represented in the Hawaiian Islands by 18 endemic taxa and one non-endemic, native species. The goals of this study were to determine whether Dryopteris in Hawai'i is monophyletic and to infer the biogeographical origins of Hawaiian Dryopteris by determining the geographical distributions of their closest living relatives. We sequenced two chloroplast DNA fragments, rbcL and the trnL-F intergenic spacer (IGS), for 18 Hawaiian taxa, 45 non-Hawaiian taxa, and two outgroup species. For individual fragments, we estimated phylogenetic relationships using Bayesian inference and maximum parsimony. We performed a combined analysis of both cpDNA fragments employing Bayesian inference, maximum parsimony, and maximum likelihood. These analyses indicate that Hawaiian Dryopteris is not monophyletic, and that there were at least five separate colonizations of the Hawaiian Islands by different species of dryopteroid ferns, with most of the five groups having closest relatives in SE Asia. The results suggest that one colonizing ancestor, perhaps from SE Asia, gave rise to eight endemic taxa (the glabra group). Another colonizing ancestor, also possibly from SE Asia, gave rise to a group of five endemic taxa (the exindusiate group). Dryopteris fusco-atra and its two varieties, which are endemic to Hawai'i, most likely diversified from a SE Asian ancestor. The Hawaiian endemic Nothoperanema rubiginosum has its closest relatives in SE Asia, and while the remaining two species, D. wallichiana and D. subbipinnata, are sister species, their biogeographical origins could not be determined from these analyses due to the widespread distributions of D. wallichiana and its closest non-Hawaiian relative.

Bayes Theorem↗
PubMed2005

A new flavanone from Dryopteris sublaeta.

AIM: To study the chemical constituents of Dryopteris sublaeta Ching et Hsu. METHODS: Fresh plant of Dryopteris sublaeta Ching et Hsu was extracted twice with boiling water, the extract was concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate, and n-butanol. The fraction of ether extract was chromatographed over silica gel column. The compounds were identified on the basis of their physiochemical and spectral data. RESULTS: Four compounds were obtained and identified as 2 (S)-5, 7, 3'-trihydroxy-6, 8-dimethyl-5'-methoxyflavanone (1), matteucinol (2), desmethoxymatteucinol (3) and 5, 7, 2'-trihydroxy-6, 8-dimethylflavanone (4). CONCLUSION: Compound 1 is a new one, the others were isolated from Dryopteris for the first time.

Chromones↗
PubMed2005

A new stilbene glycoside from Dryopteris sublaeta.

AIM: To study the chemical constituents of Dryopteris sublaeta Ching et Hsu. METHODS: Fresh plant of Dryopteris sublaeta ching et hsu was extracted twice with boiling water, concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate, and n-butanol. The fraction of ethyl acetate extract was chromatographed over macroporous adsorption resin (Diaion HP-20) eluted with a mixture of H2O and MeOH in increasing MeOH content. Their fractions from resin were repeatedly chromatographed over Toyopearl HW-40, Sephadex LH-20 and silica gel column chromatography. The compounds were identified on the basis of their physiochemical and spectral data. RESULTS: Four compounds were obtained and identified as 3,5-dihydroxy-stilbene-3-O-neohesperidoside (1), 3,5-dihydroxy-stilbene-3-O-beta-D-glucoside (2), polydotin peceid (3) and 3,5,4'-trihydroxy-bibenzyl-3-O-beta-D-glucoside (4). CONCLUSION: Compound 1 is a new compound, the others were isolated from Dryopteris for the first time.

Dryopteris↗
PubMed2002

Seasonal changes in polar lipids in fronds of the ferns Dryopteris filix-mas and Matteuccia struthiopteris.

The distribution pattern of total lipids, glyco- and phospholipids, and one betaine lipid (DGTS) in the fronds ofthe ferns Dryopteris filix-mas and Matteuccia struthiopteris was studied. The lipid composition of the embryo leaflets forming a bud, or "treble clef", and that of fully opened leaves changed throughout the growth season. The maximum amount of DGTS in clefs and mature leaves was detected at the beginning of the season. By midsummer, the DGTS content decreased, dropping to zero in the fully opened leaves, and then increased again. The amount of DGTS in the clefs collected in October versus those collected in May was somewhat higher in the case of Dryopteris filix-mas and almost twofold lower in the case of Matteuccia struthiopteris. The ratio between polar lipids contained in the clefs and mature leaves throughout the growth season was determined.

Betaine↗
PubMed2006

Phenolic constituents from the rhizomes of Dryopteris crassirhizoma.

A new phenolic glycoside, dryopteroside (1), was isolated from the rhizomes of Dryopteris crassirhizoma (Dryopteridaceae), together with five known compounds, 4beta-carboxymethyl-(-)-epicatechin (2), isobiflorin (3), biflorin (4), 1-beta-D-glucopyranosyloxy-3-methoxy-5-hydroxybenzene (5) and (+)-catechin-6-C-beta-D-glucopyranoside (6). The new compound was elucidated to be 1-butanoyl-3-C-beta-D-glucopyranosyl-5-methyl-phloroglucinyl-6-O-beta-D-glucopyranoside (1) by chemical and various spectroscopic analyses. The known compounds 2-6 were first reported from the genus Dryopteris.

Carbohydrate Sequence↗
PubMed1988

Early quantitative method for measuring germination in non-green spores of Dryopteris paleacea using an epifluorescence-microscope technique.

A method is described to determine germination by blue-light excited red fluorescence in the positively photoblastic spores of Dryopteris paleacea Sw. This fluorescence is due to chlorophyll as evidenced from 1) a fluorescence-emission spectrum in vivo, where a bright fluorescence around 675 nm is obtained only in red light (R)-irradiated spores and 2) in vitro measurements with acetone extracts prepared from homogenized spores. Significant amounts of chlorophyll can be found only in R-treated spores; this chlorophyll exhibits an emission band around 668 nm, when irradiated with 430 nm light at 21 degrees C. Compared to other criteria for germination, such as swelling of the cell, coat splitting, greening, and rhizoid formation, which require longer periods after induction for their expression, chlorophyll fluorescence can be used to quantify germination after two days. This result is confirmed by fluence-response curves for R-induced spore germination; the same relationship between applied R and germination is obtained by the evaluation with the epifluorescence method 2 days after the light treatment as compared with the evaluation with bright-field microscopy 5 days after the inducing R. Using this technique we show for the first time that Ca2+ contributes to the signal-transduction chain in phytochrome-mediated chlorophyll synthesis in spores of Dryopteris paleacea.

Calcium↗
PubMed2000

Population-specific gender-biased hybridization between Dryopteris intermedia and D. carthusiana: evidence from chloroplast DNA.

As has been shown for many kinds of organisms, barriers to interspecific hybridization may differ in strength between reciprocal crosses, resulting in a bias in the probability that one or the other species may be the maternal or paternal parent of hybrids. The fern Dryopteris Xtriploidea, the "backcross" hybrid between the diploid D. intermedia and the tetraploid D. carthusiana, occurs in large numbers in nature, providing an opportunity to investigate whether such a bias exists. Differences in the chloroplast genome distinguishing the two parental species were discovered in the sequence of the trnL region following amplification by polymerase chain reaction (PCR), including a Mse I restriction site. This allowed rapid identification of the donor of the chloroplast genome, and therefore the maternal parent of each hybrid, assuming chloroplast DNA to be maternally inherited in Dryopteris. Analysis was carried out on 127 hybrids, shown to be of independent origin using allozymes, occurring at three localities in Virginia and West Virginia. When samples from all localities were pooled, 91 possessed the D. carthusiana trnL genotype and 36 possessed the D. intermedia genotype, a ratio that is significantly different (P < 0.001) from the null hypothesis of no gender bias. The strength of the bias differed significantly among the three sites, however, with bias at the West Virginia site much stronger (5.6:1 carthusiana:intermedia; P < 0.001) than at either Virginia site (1.55:1 and 1.43:1 carthusiana:intermedia, respectively; P > 0.05 in both cases). The cause of the strong bias in the West Virginia sample is unknown, as is the cause of the population differences. Causes of bias could include differences between the parental species related to their ploidy difference, including sizes of gametes and/or gametangia, sperm motility, breeding system (D. intermedia is outcrossing while D. carthusiana is selfing), or the nature and strength of interspecific isolating mechanisms.

Journal Article↗
PubMed2001

[Morphogenesis of the sexual phase of six Mexican species of the Dryopteris (Dryopteridaceae), Part II].

The development of the sexual phase of six Mexican species of Dryopteris is described and compared. Spores of all studied species are monolete, ellipsoid and have a rugose surface; the perine is folded, brown to dark brown, with a tubercled outline. Germination pattern is of the Vittaria-type and the development pattern of the prothallia is of the Aspidium-type. Gametangia are of the common type for the leptosporangiate advanced ferns. First leaves of the sporophytes appear 258-265 after sowing and apparently in Dryopteris pseudo-filix-mas the sporophyte have an apogamic origin (80 days). To make a comparative analysis of gametophytic characteristics in the twelve Mexican species and conclude of germination is of the Vittaria-type and development pattern prothallial is of the Aspidium-type, and unicelular trichomes on margin and superficial gametophytic to yield irregular aspect are characteristics to yield unit and characteristic to genera to conform Dryopteridaceae family (sensu Moran 1995) with the exception of Didymochlaena genus.

Germination↗
PubMed1996

[Correlative study on the storage time and quality of rhizoma Dryopteris crassirhizomae].

The contents of dryocrassin in Rhizoma Dryopteris Crassirhizomae were determined by TLC-scanning in a period of two years of storage. Phloroglucinol content was calculated by area normalization method. The results show that in contrast with the fresh crude drugs of Rhizoma Dryopteris Crassirhizomae, the contents of dryocrassin in the crude drugs of one year and two years of storage have reduced by 22% and 27% respectively, and phloroglucinol contents have reduced by 2% and 8% respectively.

Benzylidene Compounds↗
PubMed2006

Exogenous and endogenous growth regulators on apogamy in Dryopteris affinis (Lowe) Fraser-Jenkins sp. affinis.

This work showed for the first time the relationship between the effect of exogenous auxins and gibberellins on apogamy in Dryopteris affinis (Lowe) Fraser-Jenkins sp. affinis and its endogenous contents during early apogamic events. The addition of NAA (0.53 and 5.37 microM) or GA(3) 2.8 microM to an MS solid medium significantly increased apogamous sporophyte formation. BA induced brown callus that regenerated sporophytes in a hormone-free medium. The endogenous contents of GA(1), GA(3), GA(4), GA(7), GA(9) and IAA were determined by GC-MS in gametophytes cultured on MS solid medium, before and during early stages of apogamous embryo development. The accumulation of both GA(9) and IAA before embryo development was evident as high levels of GA(4) in the earliest analysed stage of embryo development and high levels of GA(3) in elongating shoots were found. The role of gibberellins on apogamy was also supported by data showing a decrease in the percentage of gametophytes developing embryos because of the addition of flurprimidol to the culture medium.

Dryopteris↗
PubMed2006

Fatty acid synthase inhibitory activity of acylphloroglucinols isolated from Dryopteris crassirhizoma.

Fatty acid synthase (FAS) is emerging as a potential therapeutic target to treat cancer and obesity. Bioassay-guided fractionation of a MeOH extract of the rhizomes of Dryopteris crassirhizoma (Dryopteridaceae), using an in vitro FAS inhibitory assay, resulted in the isolation of a series of acylphloroglucinols, as the active principles. The isolates 1-10 inhibited FAS with IC50 values ranging from 23.1+/-1.4 to 71.7+/-3.9 microM. The results of the present study indicate that the acylphloroglucinol derivatives could be considered to be a promising class of FAS inhibitors.

Acylation↗
PubMed2004

Overwintering leaves of a forest-floor fern, Dryopteris crassirhizoma (Dryopteridaceae): a small contribution to the resource storage and photosynthetic carbon gain.

BACKGROUND AND AIMS: Dryopteris crassirhizoma is a semi-evergreen fern growing on the floor of deciduous forests. The present study aimed to clarify the photosynthetic and storage functions of overwintering leaves in this species. METHODS: A 2-year experiment with defoliation and shading of overwintering leaves was conducted. Photosynthetic light response was measured in early spring (for overwintering leaves) and summer (for current-year leaves). KEY RESULTS: No nitrogen limitation of growth was detected in plants subjected to defoliation. The number of leaves, their size, reproductive activity (production of sori) and total leaf mass were not affected by the treatment. The defoliation of overwintering leaves significantly reduced the bulk density of rhizomes and the root weight. The carbohydrates consumed by the rhizomes were assumed to be translocated for leaf production. Photosynthetic products of overwintering leaves were estimated to be small. CONCLUSION: Overwintering leaves served very little as nutrient-storage and photosynthetic organs. They partly functioned as a carbon-storage organ but by contrast to previous studies, their physiological contribution to growth was found to be modest, probably because this species has a large rhizome system. The small contribution of overwintering leaves during the short-term period of this study may be explained by the significant storage ability of rhizomes in this long-living species. Other ecological functions of overwintering leaves, such as suppression of neighbouring plants in spring, are suggested.

Carbon↗