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PubMed2003

Removal of copper ions from aqueous solution by tree fern.

Tree fern, an agricultural by-product, was used for the sorptive removal of copper ions from aqueous solution. The experimental data was analysed by Langmuir, Freundlich and Redlich-Peterson isotherms. The equilibrium sorption capacity of copper ions was determined from the Langmuir equation and found to be 11.7 mg/g. A batch sorption model, based on the assumption of the pseudo-second-order mechanism, was developed to predict the rate constant of sorption, the equilibrium sorption capacity and the initial sorption rate with the effect of initial copper ion concentration and the tree fern dose. Various thermodynamic parameters, such as Delta G(0), Delta H(0) and Delta S(0), have been calculated. The thermodynamics of copper ion/tree fern system indicates spontaneous and endothermic nature of the process.

Adsorption↗

PubMed2003

Arsenic biomonitoring using a hyperaccumulator fern (Pteris vittata).

Samples of Pteris vittata L. (brake fern or ladder brake) collected in Genova and in areas outside urban centres, have been analysed for arsenic content in order to assess if hyper accumulating plants are suitable for monitoring purposes. Hyper accumulation ability of the Ligurian fern populations was evaluated by analysing specimens grown with hydroponic media added with As(v). Arsenic concentrations in the range 2-310 microg g(-1) dry weight have been measured in samples collected in different sites along the Ligurian coast. Arsenic concentrations in fern fronds correlate with the estimated arsenic emission in the area, verifying the applicability of P. vittata as an arsenic biomonitor.

Arsenic↗

PubMed2002

Ultrasonographic evaluation of urinary bladder in normal, fern fed and enzootic bovine haematuria-affected cattle.

A total of 19 adult hill cattle of both sexes were subjected to trans-rectal ultrasound scanning of urinary bladder to evaluate bladder wall thickness and the presence of space-occupying lesions. The animals were divided into four groups. Eight apparently healthy hill cattle maintained under standard ration served as control (group I) and the remaining II animals were divided into three groups (II, III and IV). Group II animals (n = 8) were fed with different type of ferns which were further divided into subgroups II-P, -D and -B and fed with Polystichum squarrosom (n = 2). Dryopteris juxtaposita (n = 2) and Pteridium aquilinum (n = 4) ferns, respectively. The one animal in group III was a natural case of enzootic bovine haematuria (EBH) and the two animals in group IV were natural cases of microscopic EBH fed with Polystichum squarrosum fern. In group I animals, the average bladder wall thickness was 1.45 mm. The delineation of the bladder wall was uniformly smooth and the echo pattern of the bladder was homogeneously black, which was suggestive of clear urine content. In group II (P, D and B) the average bladder wall thickness of the six animals was 1.87 mm and the sonographic features were within normal limit when compared with controls. In two of the animals of group II-B, the bladder wall was apparently thick (4.36 mm) and there was no intraluminal mass except at one or two focal elevated points. Animals of groups III and IV showed the average bladder wall thickness of 4.86 mm and were characterized by the presence of irregular sessile masses extending into the bladder lumen. The homogeneous anechoic area was reduced centrally due to the presence of a hypoechoic soft tissue mass all around the bladder wall. Post-sonographic urinalysis, biopsy and necropsy of selected cases further confirmed the sonographic findings.

Animal Feed↗

PubMed2003

Arsenic uptake by native fern species in Thailand: effect of chelating agents on hyperaccumulation of arsenic by Pityrogramma calomelanos.

Nineteen native fern species collected from an area in Thailand with high arsenic concentration in soil and in ground water as a result of tin mining was screened for elevated arsenic concentration in fronds. Two species of fern were found to contain elevated arsenic in their fronds in nature: Pityrogramma calomelanos (108-1156 microg g(-1) dried weight) and Pteris vittata (79 microg g(-1) dried weight). Under hydroponic culture Pityrogramma calomelanos (a silver back fern) accumulated arsenic in its shoot at rate of 4616 microg(-1) (dried weight). The accumulation of arsenic in Pityrogramma calomelanos shoot doubled with the addition of an EDTA (Ethelenediamine tetraacetic acid) chelating agent. The highest accumulation occurred 6 weeks after exposure to 10 mg L(-1) arsenic as disodium hydrogen arsenate. The addition of another chelating agent, DMS (Dimercaptosuccinic acid), resulted in a 5-fold decrease in arsenic concentration in the Pityrogramma calomelanos shoot compared to control after 6 weeks of exposure to arsenic. The contrasting effect of the EDTA and DMSA chelating agent was attributed to the strong binding of the thiol group to arsenic ion. This study indicated that Pityrogramma calomelanos uptake and translocate arsenic in the form of arsenate and arsenite rather than the As-DMSA complex. Using phytoextraction efficiency calculations, it was determined that Pityrogramma calomelanos gave the highest arsenic phytoextraction efficiency at 6 weeks after exposure to arsenic in the EDTA treatment, with an efficiency of 77.8 mg As based on whole plant biomass.

Arsenic↗

PubMed2006

Conserved features of germination and polarized cell growth: a few insights from a pollen-fern spore comparison.

BACKGROUND: The germination of both pollen and fern spores results in the emergence of a cell-pollen tube from pollen, rhizoid from spore-that grows in a polar fashion, primarily at its apical end. In both of these tip-growing cells, the delivery of secretory vesicles to the growing end is guided in part by a calcium gradient, with calcium entering at the tip where it is most highly concentrated. The similarities between the two systems extend beyond tip-focused calcium gradients to encompass signalling pathways and elements including calmodulin, nitric oxide, annexins and Rop-GTPases. SCOPE AND AIMS: This review is limited to those pathways and elements that function similarly in fern and pollen systems based on currently available evidence. The aim is to illustrate the common mechanisms by which tip growth occurs, facilitate further investigations into this area, and examine the implications for the evolutionarily conserved control of tip growth. CONCLUSIONS: The interplay of calcium, nitric oxide and other effectors in both pollen and fern spores suggests certain signalling pathways became important regulators of germination and growth early in the evolution of land plants. Both large- and small-scale comparative genomic methods have shown to be promising in their ability to find new and relevant comparisons for further research. Cross-species comparisons may serve to speed up this process by highlighting both basic pathways and system-specific deviations.

Arabidopsis↗

PubMed2005

Gene transfer from a parasitic flowering plant to a fern.

The rattlesnake fern (Botrychium virginianum (L.) Sw.) is obligately mycotrophic and widely distributed across the northern hemisphere. Three mitochondrial gene regions place this species with other ferns in Ophioglossaceae, while two regions place it as a member of the largely parasitic angiosperm order Santalales (sandalwoods and mistletoes). These discordant phylogenetic placements suggest that part of the genome in B. virginianum was acquired by horizontal gene transfer (HGT), perhaps from root-parasitic Loranthaceae. These transgenes are restricted to B. virginianum and occur across the range of the species. Molecular and life-history traits indicate that the transfer preceded the global expansion of B. virginianum, and that the latter may have happened very rapidly. This is the first report of HGT from an angiosperm to a fern, through either direct parasitism or the mediation of interconnecting fungal symbionts.

Ferns↗

PubMed2026

Co-option of stomata in the convergent evolution of fern nectaries.

Understanding the origin of new structures is a central goal of evolutionary biology. In many instances, novel phenotypes arise through heterotopy: the expression of a structure in a new location. Using bracken fern (Pteridium aquilinum) as a model, we combine genomics, transcriptomics and metabolomics to begin to explore the origin and developmental routes in the convergent evolution of ant-enticing nectaries. We observe that P. aquilinum does not exclusively express flowering plant 'nectary genes' during nectary development. Rather, this fern builds nectaries through co-option of stomata. Specifically, P. aquilinum heterotopically expresses canonical angiosperm stomatal regulatory genes, leading to stomatal development in novel positions along the petiole. These non-laminar stomata were co-opted for nectar secretion through the expression of putative sugar transport genes, forming secretory nectarostomata. This work provides two advances in our understanding of nectary evolution and the origin of complex structures. First, heterotopic expression of stomata, and later exaptation, represents one realized developmental mechanism for the evolution of nectar glands. Second, while there are many routes to nectary evolution, nectarostomata development is a repeatable path that has evolved in ferns and flowering plants, representing an impressive case of convergent evolution through the same developmental mechanism, despite over 400 million years of divergent history.

Plant Stomata↗

PubMed2007

Are correlations among foliar traits in ferns consistent with those in the seed plants?

Broad-based studies of gymnosperms and angiosperms reveal consistent and functionally significant correlations among foliar traits such as leaf mass per area (LMA), maximum photosynthetic rate (A(area)), foliar nitrogen (N(area)), foliar chlorophyll (Chl) and leaf longevity. To assess the generality of these relationships, we studied 20 fern species growing in the understorey of a temperate deciduous forest. We found that foliar N(area) increases with LMA, and that foliar N(area) and A(area) are positively correlated with one another, as are foliar N(area) and Chl. The ferns in general have very low LMA compared with most seed plants; A(area), N(area) and Chl are below median values for seed plants but are not extreme. Species with overwintering fronds have significantly higher LMA than species with fronds that senesce at the end of the growing season, as well as a significantly higher C : N ratio in frond tissue and relatively high foliar N on an areal basis. Correlations among foliar traits associated with gas exchange in these forest understorey ferns are in accordance with patterns reported for seed plants, suggesting a high degree of functional constraint on the interrelationships among key elements in foliar design.

Carbon↗

PubMed2001

Indication of global deforestation at the Cretaceous-Tertiary boundary by New Zealand fern spike.

The devastating effect on terrestrial plant communities of a bolide impact at the Cretaceous-Tertiary boundary is shown in fossil pollen and spore assemblages by a diverse flora being abruptly replaced by one dominated by a few species of fern. Well documented in North America, this fern spike signals widespread deforestation due to an impact winter or massive wildfires. A Southern Hemisphere record of a fern spike, together with a large iridium anomaly, indicates that the devastation was truly global. Recovery of New Zealand plant communities followed a pattern consistent with major climatic perturbations occurring after an impact winter that was possibly preceded by global wildfires.

Animals↗

PubMed2001

Occurrence of polygodial and 1-(2,4,6-trimethoxyphenyl)-but-2-en-1-one from some ferns and liverworts: role of pungent components in bryophytes and pteridophytes evolution.

The New Zealand fern Blechnum fluviatile and liverwort, Hymenophyton flabellatum produce the characteristic pungent compounds, (-)-polygodial, a sesquiterpene dialdehyde, and 1-(2,4,6-trimethoxyphenyl)-but-2-en-1-one, respectively. The former compound has been isolated from the Japanese liverwort, Porella vernicosa complex and the latter one from the Japanese fern, Arachinoides standishii. The occurrence of both compounds in both pteridophytes and bryophytes provides another important link between bryophytes and ferns.

Alkenes↗

PubMed2001

Pathological evaluation of Polystichum squarrosum (D. Don) fern in laboratory rats.

Polystichum squarrosum fern fed (30% w/w) rats showed moderate mortality, decrease in body weight, less body fat and splenomegaly. On post-mortem examination, significant gross lesions were not seen in sacrificed animals. Histopathologically, Polystichum fed rats showed dilated Virchow Robin's space in brain, mild to moderate vascular changes likeoedema, engorgement of blood vessels and haemorrhages in most of the visceral organs, interstitial pneumonia in lungs, focal necrosis and generalised vacuolative degenerative changes in liver, more haemosiderin deposition and presence of higher number of megakaryocytes in spleen, shrunken glomeruli, more peri-glomerular space and more number of glomeruli per microscopic field in kidneys, focal hyperplasia of urinary bladder and moderate to marked depletion of germinal epithelium and spermatids in seminiferous tubules of testes. Pathologically, progressive changes were observed only in liver, urinary bladder and testes on 180 days post feeding (DPF). One fern fed rat sacrificed on 135 DPF showed hepatic tumour which was diagnosed as hepatocellular carcinoma. The results showed that P. squarrosum produced almost comparable pathological changes/preneoplastic lesions as reported in bracken fern fed animals. Long term exposure studies (i.e. 2 yrs) are desired.

Animals↗

PubMed1988

Chromosome aberrations in cattle raised on bracken fern pasture.

Thirteen cows maintained on natural bracken fern (Pteridium aquilinum) were analyzed cytogenetically. The frequency of structural chromosome aberrations detected in peripheral blood cells was significantly higher when compared to that detected in animals raised on pasture containing no bracken fern. We discuss the clastogenic action of fern and its synergistic action with infection by type 2 and 4 papilloma virus in the same animals.

Animal Feed↗

PubMed1996

Tear and saliva ferning tests in Sjögren's syndrome (SS).

The purpose of this study was to evaluate the tear ferning test (TFT) and the saliva ferning test (SFT) as diagnostic tests for xerophthalmia and xerostomia respectively in patients with SS. Dried samples of freshly produced tears and saliva from: (A) 36 healthy controls without sicca symptoms, (B) 61 patients with primary SS, (C) 53 patients with secondary SS and (D) 22 patients with psychiatric disorders receiving antidepressants, were examined by polarizing light microscopy. All individuals included in the study were postmenopausal women. The crystallization was classified into 4 types according to the ferning phenomenon: uniformity, branching, spreading and integrity (type I normal and II, III, IV abnormal). Abnormal TFT was found in tear samples of: (A) 8/72 normal control eyes, (B) 110/122 prim SS eyes, (C) 86/106 sec SS eyes and (D) 30/44 psychiatric patients' eyes. Abnormal SFT was found in: (A) 6/36 of normal controls, (B) 59/61 of prim SS, (C) 51/53 of sec SS patients and (D) 16/22 of psychiatric patients. The differences of both TFT and SFT of patients with prim SS and sec SS versus controls were significant (p < 0.001). The sensitivity of TFT was found to be high both in prim SS (90%) and in sec SS (81%). In addition the specificities of TFT and SFT were high 89% and 83% respectively. On the other hand the differences of TFT and SFT in psychiatric patients receiving antidepressants versus normal controls were also significant (p < 0.05 and p < 0.025 respectively). According to our data TFT and SFT are simple, sensitive and specific tests to evaluate xerophthalmia and xerostomia in SS and probably in other conditions characterized by mucous membrane dryness.

Crystallization↗

PubMed1990

The ferning test for detection of amniotic fluid contamination in umbilical blood samples.

There is currently no standard means of detecting amniotic fluid contamination in fetal blood obtained by percutaneous umbilical blood sampling. The ferning test is proposed for this purpose. An in vitro model, using centrifuged serial dilutions of neonatal cord blood and amniotic fluid, showed that ferning of the supernatant occurs in proportion to the degree of contamination. A system for grading ferning was devised, and tested in a blind trial. For the detection of amniotic fluid contamination of 10% or more, the method showed a sensitivity of 98% and a specificity of 81%. The method may be useful in percutaneous umbilical blood sampling, and in the diagnosis of spontaneous rupture of membranes with vaginal bleeding.

Amniotic Fluid↗

PubMed1989

Influence of the carcinogenic pollutant benzo[a]pyrene on plant development: fern gametophytes.

Polycyclic aromatic hydrocarbons (PAHs), ubiquitous environmental pollutants, are known to be biologically active in mammalian systems and are accumulated by plants. A few reports suggest that PAHs stimulate growth in plants and induce morphogenesis in plant tissue in culture. To investigate the growth altering abilities of PAHs in plants, polypodiaceous fern gametophytes were grown under sterile conditions on media containing a biologically active PAH, benzo[a]pyrene (BaP), at doses ranging from 0.1 to 10.0 micrograms/ml. The growth pattern of polypodiaceous fern gametophytes enables alterations in growth and morphogenesis to be observed at the cellular level in an intact plant. Doses of BaP in the range 0.1--3.2 micrograms/ml enhanced the onset of the morphological transitions from 1-dimensional (1D) to 2-dimensional (2D) growth. This transition for BaP treated plants occurred after fewer cell divisions than the corresponding solvent and untreated controls. The low (0.1 and 0.32 micrograms) and high (1.0 and 3.2 micrograms) doses of BaP were found to accelerate and inhibit cell proliferation, respectively. The 10.0 microgram dose was toxic and resulted in decreased germination of spores and reduced survival of plants. A slight but significant decrease in survival was also observed in ferns treated with 3.2 micrograms. This is the first example of PAH influencing cell differentiation in a whole plant system.

Benzo(a)pyrene↗

PubMed2006

Bracken-fern extracts can be clastogenic or aneugenic depending on the tissue cell assay.

The consumption of bracken fern (Pteridium aquilinum) as food is associated with a high incidence of cancer in humans and animals. We investigated the cytogenetic effects of bracken-fern extracts (hexane extract-HE, ethanol extract-EE, hot water extract-HWE and cold water extract-CWE) on chromosomes of peritoneal and bone-marrow cells of Swiss mice. In peritoneal cells, all four treatments (HE, EE, HWE and CWE) induced structural chromosome aberrations, but the EE also induced numerical chromosome aberrations. In bone-marrow cells both HE and CWE induced structural chromosome aberrations; additionally, the number of abnormal metaphases was higher in peritoneum than in bone marrow. We suggest that bracken fern induces cytogenetic damage through DNA strand breaks and affects chromosome segregation.

Aneuploidy↗

PubMed2002

Bracken fern-induced malignant tumors in rats: absence of mutations in p53, H-ras and K-ras and no microsatellite instability.

Bracken fern (genus Pteridium) has been shown to induce tumors in domestic and experimental animals. Epidemiological studies have also shown an association between human exposure to bracken toxins and increased risk for the development of upper gastrointestinal tract tumors. Our aim in this study was to investigate possible genomic alterations in bracken fern-induced tumors of experimental animals searching for molecular markers that might be used for human epidemiological studies. Using human colorectal carcinogenesis as a molecular model, we examined eight malignant bracken fern-induced tumors of rats for mutations in the genes associated with the "classic pathway" of colorectal cancer, i.e. p53 and ras, and also in the "mutator pathway" by evaluating microsatellite instability. Exons 5-9 of the p53 gene and exons 1 and 2 of the K-ras and H-ras genes were examined by DNA sequencing and no mutations were found in any of the eight tumors. Amplification of five previously validated microsatellite loci (one with mono-, three with di- and one with tetra-nucleotide repeat motifs) in the malignant tumors and in the surrounding normal tissue did not reveal any instability. The involvement of epigenetic alterations or of mutations in other tumor suppressor genes or oncogenes should be further investigated in the search for human epidemiological markers.

Animals↗

PubMed2001

Evaluation of the fern Azolla for growth, nitrogen and phosphorus removal from wastewater.

Water fern (Azolla filiculoides Lam.) has been assessed for nitrogen and phosphorus removal in outdoor experiments comparing sewage water (S) from an experimental aquaculture plant, well water (W) and mineral growth medium Hoagland (H). The experiments were undertaken during the spring and the summer. The yield of fern biomass and nitrogenase activity was higher in H than in W and S waters. The enzyme activity had a decreasing trend with significant differences (p < 0.05) in the three waters. Peroxidase (POD) activity in April decreased with significative differences in W and S waters (p < 0.05). The electrical conductivity and the concentrations of NO3- in the three waters decreased significantly (p < 0.05). The highest removal of nitrate from the media was obtained in July. In S water, NO2- concentration decreased, while it increased in W water. PO(4)3- concentration was very low in W and S waters and decreased in H medium. The results obtained confirm the ability of the fern to grow in sewage water.

Nitrogen↗