| enzymatic isolation and structural characterisation of polymeric suberin of cork from quercus suber l. | an enzymatic method has been used to isolate, for the first time, polymeric suberin from the bark of quercus suber l. or cork. this was achieved by solvent extraction (dichloromethane, ethanol and water), followed by a step-by-step enzymatic treatment with cellulase, hemicellulase and pectinase, and a final extraction with dioxane/water. the progress of suberin isolation was monitored by fourier transform infrared spectroscopy using a photoacoustic cell (ftir-pas). the material obtained (polymer ... | 2001 | 11164227 |
| influence of weather on cork-ring width. | ring-width series of cork from quercus suber l. trees growing at two sites in extremadura (southwestern spain) were analyzed in relation to monthly precipitation and temperature, and to climatic indices combining both variables. ring width of cork showed strong positive correlations with precipitation, especially during the fall and winter. moderately low temperatures were favorable for cork growth, except in winter and during the onset of phellogen activity. we conclude that drought or temperat ... | 2000 | 11303579 |
| frequent cytoplasmic exchanges between oak species that are not closely related: quercus suber and q. ilex in morocco. | chloroplast (cp) and mitochondrial (mt) dna variation were studied in 97 populations of cork oak (quercus suber) in morocco; in 31 of these populations, holm oak (quercus ilex), a clearly distinct species, also occurred and was compared with q. suber. three cpdna and one mtdna primer pairs were used in the survey, each in combination with one restriction enzyme. six haplotypes belonging to two very divergent lineages were detected; one lineage predominates in each species, and is probably ancest ... | 2001 | 11555243 |
| cryopreservation of quercus suber and quercus ilex embryonic axes: in vitro culture, desiccation and cooling factors. | this study examines different factors included in the cryopreservation protocols for quercus ilex and q. suber embryonic axes. in vitro incubation temperature played an important role in the appropriate development of q. ilex axes, as 15 degrees c was superior to 25 degrees c. q. suber axes proved to be more sensitive to desiccation and cooling. poor survival (35%) was observed when axes were included into cryovials and then in liquid nitrogen, and none when immersed in sub-cooled liquid nitroge ... | 2002 | 12447487 |
| effect of tannins from quercus suber and quercus coccifera leaves on ethanol-induced gastric lesions in mice. | the gastroprotective effects of 70% acetone extracts of quercus suber and quercus coccifera leaves and of tannins (pedunculagin, castalagin, phillyraeoidin a, and acutissimin b) purified from these extracts were examined in the mouse using the ethanol-induced gastric ulcer model. both extracts (25, 50, and 100 mg/kg), given orally, prevented the formation of ethanol-induced lesions in the stomach. the percent protection varied between 68 and 91%. purified tannins (50 mg/kg) were also effective i ... | 2003 | 12590500 |
| diplopyrone, a new phytotoxic tetrahydropyranpyran-2-one produced by diplodia mutila, a fungus pathogen of cork oak. | a new phytotoxic monosubstituted tetrahydropyranpyran-2-one, named diplopyrone (1), was isolated from the liquid culture filtrates of diplodia mutila, a plant pathogenic fungus causing a form of canker disease of cork oak (quercus suber). diplopyrone was characterized, using spectroscopic and chemical methods, as 6-[(1s)-1-hydroxyethyl]-2,4a,6,8a-tetrahydropyran[3,2-b]pyran-2-one. the absolute stereochemistry of the chiral secondary hydroxylated carbon (c-9), determined by application of mosher' ... | 2003 | 12608876 |
| a 10-kda class-ci shsp protects e. coli from oxidative and high-temperature stress. | we report on a new cdna clone (qshsp10.4-ci) of a quercus suber l. class-ci small heat-shock protein (shsp) obtained from cork (phellem), a highly oxidatively stressed plant tissue. the deduced gene product lacks the c-terminal extension and the consensus i region of the alpha-crystallin domain, being the most c-terminally truncated shsp reported to date. in an attempt to prove that a protective function is possible for such a truncated shsp, we overexpressed in escherichia coli three recombinan ... | 2003 | 12743825 |
| runoff erosion and nutrient depletion in five mediterranean soils of ne spain under different land use. | we investigated the influence of agricultural management and various plant covers related to the period of abandonment on soil properties, erosion and nutrient depletion in a typical mediterranean area with sandy loam shallow soils. cultivated soils (cs) with insufficient management, 5 year abandoned soils covered with meadow (a5), 25 year abandoned soils covered with dense scrubs (a25), 50 year abandoned soils covered with cork trees (a50) and soils in a 50 year pine reforested area (p50) were ... | 2003 | 12798105 |
| phenolic compounds and fatty acids from acorns (quercus spp.), the main dietary constituent of free-ranged iberian pigs. | the aim of the present work was to identify and quantify the phenolic compounds and fatty acids in acorns from quercus ilex, quercus rotundifolia, and quercus suber. the concentration of oleic acid was >63% of total fatty acids in all cases, followed by palmitic and linoleic acids at similar concentrations (12-20%). the concentrations of alpha-tocopherol in q. rotundifolia, q. ilex, and q. suber were 19, 31, and 38 mg/kg of dry matter (dm), respectively, whereas the concentrations of gamma-tocop ... | 2003 | 14518951 |
| genetic transformation of selected mature cork oak (quercus suber l.) trees. | a transformation system for selected mature cork oak (quercus suber l.) trees using agrobacterium tumefaciens has been established. embryos obtained from recurrent proliferating embryogenic masses were inoculated with a. tumefaciens strains eha105, lba4404 or agl1 harbouring the plasmid pbinubigusint [carrying the neomycin phosphotransferase ii (nptii) and beta-glucuronidase (uida) genes]. the highest transformation efficiency (4%) was obtained when freshly isolated explants were inoculated with ... | 2004 | 15185122 |
| a plant type 2 metallothionein (mt) from cork tissue responds to oxidative stress. | expression of plant metallothionein genes has been reported in a variety of senescing tissues, such as leaves and stems, ripening fruits, and wounded tissues, and has been proposed to function in both metal chaperoning and scavenging of reactive oxygen species. in this work, it is shown that mt is also associated with suberization, after identifying a gene actively transcribed in quercus suber cork cells as a novel mt. this cdna, isolated from a phellem cdna library, encodes a mt that belongs to ... | 2004 | 15448172 |
| quercus suber cork extract displays a tensor and smoothing effect on human skin: an in vivo study. | recently, it has become indispensable for anti-aging active ingredients to provide a visible and immediate smoothing antiwrinkle effect. in quercus suber, suberin is the most important structural component of cork cell walls. studies have shown that suberin is made up mostly of hydroxycarboxylic acids and that it is endowed with many special mechanical and chemical properties that evoke a possible smoothing effect on the surface of the skin. therefore, we were interested in investigating the eff ... | 2005 | 16033247 |
| phylogeographical variation of chloroplast dna in cork oak (quercus suber). | in the last decades, the geographical location of the centre of origin of quercus suber (cork oak), a strictly western mediterranean oak species, has been the subject of controversy. | 2005 | 16103038 |
| effect of carbon and nitrogen sources, ph and temperature on in vitro culture of several isolates of amanita caesarea (scop.:fr.) pers. | several isolates were obtained from sporocarps of amanita caesarea (scop.: fr.) pers. associated with quercus suber and castanea sativa coming from the southwest of spain. culture conditions were optimized for these isolates. the largest radial growth was obtained at ph 6-7, and optimal growth temperature was 24-28 degrees c depending on the isolate. albumin bovine and nitrate produced the largest patch size diameters, but the greatest mycelium dry weight yields were obtained with ammonium. mann ... | 2006 | 16292570 |
| diplobifuranylones a and b, 5'-monosubstituted tetrahydro-2h-bifuranyl-5-ones produced by diplodia corticola, a fungus pathogen of cork oak. | two new 5'-monosubstituted tetrahydro-2h-bifuranyl-5-ones, named diplobifuranylones a and b (1 and 2), were isolated from the culture filtrates of diplodia corticola, the causal agent of a canker of cork oak (quercus suber). the same fungus also produced eight known metabolites, namely, the diplopyrone, (3s,4r)-trans- and (3r,4r)-cis-4-hydroxymellein, sapinofuranone b and its (s,s)-enantiomer, and sphaeropsidins a-c. diplobifuranylones a and b (1 and 2) were characterized, using spectroscopic an ... | 2006 | 16643050 |
| cork oak trees (quercus suber l.). | a transformation system for selected mature quercus suber l. trees using agrobacterium tumefaciens has been established. embryos obtained from recurrent proliferating embryogenic masses are inoculated with agl1 strain harbouring the plasmid pbinubigusint, which carries the nptii and uida genes. evidence of stable transgene integration is obtained by polymerase chain reaction for nptii and uida genes, southern blotting and expression of the uida gene. the transgenic embryos are germinated and suc ... | 2006 | 17033056 |
| sewage sludge effects on mesofauna and cork oak (quercus suber l.) leaves decomposition in a mediterranean forest firebreak. | effects of sewage sludge on litter mesofauna communities (collembola and acari) and cork oak (quercus suber l.) leaf litter decomposition have been studied during 18 mo using litterbags in an in situ experimental forest firebreak in southeastern france. the sludge (2.74 t dm ha(-1) yr(-1)) was applied to fertilize and maintain a pasture created on the firebreak. litterbag colonization had similar dynamics on both the control and fertilized plots and followed a typical mediterranean pattern showi ... | 2006 | 17071899 |
| water-use strategies in two co-occurring mediterranean evergreen oaks: surviving the summer drought. | in the mediterranean evergreen oak woodlands of southern portugal, the main tree species are quercus ilex ssp. rotundifolia lam. (holm oak) and quercus suber l. (cork oak). we studied a savannah-type woodland where these species coexist, with the aim of better understanding the mechanisms of tree adaptation to seasonal drought. in both species, seasonal variations in transpiration and predawn leaf water potential showed a maximum in spring followed by a decline through the rainless summer and a ... | 2007 | 17331898 |
| pre-exposure to ozone predisposes oak leaves to attacks by diplodia corticola and biscogniauxia mediterranea. | one-year-old cork oak (quercus suber) and turkey oak (q. cerris) seedlings were exposed to ozone (110 ppb, 5 h day(-1), for 30 days) and were inoculated with diplodia corticola and biscogniauxia mediterranea, respectively, by spraying a suspension of spores on the leaves. both fungi are endophytic and may act as weak parasites, contributing to oak decline. ozone exposure stimulated leaf attacks after inoculation, although the physiological, visible, and structural responses of both oaks to o3 ex ... | 2007 | 17450300 |
| regulation of transpirational water loss in quercus suber trees in a mediterranean-type ecosystem. | sap flux density in branches, leaf transpiration, stomatal conductance and leaf water potentials were measured in 16-year-old quercus suber l. trees growing in a plantation in southern portugal to understand how evergreen mediterranean trees regulate water loss during summer drought. leaf specific hydraulic conductance and leaf gas exchange were monitored during the progressive summer drought to establish how changes along the hydraulic pathway influence shoot responses. as soil water became lim ... | 2007 | 17472943 |
| the cd(ii)-binding abilities of recombinant quercus suber metallothionein: bridging the gap between phytochelatins and metallothioneins. | in this work, we have analyzed both at stoichiometric and at conformational level the cd(ii)-binding features of a type 2 plant metallothionein (mt) (the cork oak, quercus suber, qsmt). to this end four peptides, the wild-type qsmt and three constructs previously engineered to characterize its zn(ii)- and cu(i)-binding behaviour, were heterologously produced in escherichia coli cultures supplemented with cd(ii), and the corresponding complexes were purified up to homogeneity. the cd(ii)-binding ... | 2007 | 17503092 |
| rhodotorula subericola sp. nov., an anamorphic basidiomycetous yeast species isolated from bark of quercus suber (cork oak). | two yeasts strains, y-31(t) and y-20b, pertaining to a previously unknown yeast species were isolated from bark of cork oak in spain. physiological characterization revealed a pattern of assimilation of carbon and nitrogen compounds compatible with members of the genus rhodotorula. from sequence analysis of the d1/d2 region of the 26s rrna gene, rhodotorula cycloclastica and rhodotorula philyla were related to the unknown species. phylogenetic reconstruction based on the d1/d2 region of the 26s ... | 2007 | 17625214 |
| differences in fine-scale genetic structure and dispersal in quercus ilex l. and q. suber l.: consequences for regeneration of mediterranean open woods. | cork oak (quercus suber l.) and holm oak (q. ilex l.) are among the most important tree species (economically and ecologically) in the western mediterranean region, where they define unique open woods (created and maintained by man) known as 'dehesas' in spain. however, these formations are under increasing threat due to the lack of regeneration. we have analysed spatial genetic structure in a mixed parkland; inferences about gene dispersal have also been performed, according to the isolation by ... | 2007 | 17971829 |
| the distribution of quercus suber chloroplast haplotypes matches the palaeogeographical history of the western mediterranean. | combining molecular analyses with geological and palaeontological data may reveal timing and modes for the divergence of lineages within species. the mediterranean basin is particularly appropriate for this kind of multidisciplinary studies, because of its complex geological history and biological diversity. here, we investigated chloroplast dna of quercus suber populations in order to detect possible relationships between their geographical distribution and the palaeogeographical history of the ... | 2007 | 17995923 |
| foraging activity and dietary spectrum of the argentine ant (hymenoptera: formicidae) in invaded natural areas of the northeast iberian peninsula. | we analyzed the foraging activity and the dietary spectrum of the argentine ant (linepithema humile mayr) and select native ants on cork oaks from mediterranean open cork oak (quercus suber) secondary forests. the study areas included invaded and noninvaded zones in close proximity. the argentine ant's daily foraging activity was correlated to the abiotic factors studied, whereas the seasonal foraging activity was related not only to the variations in the average air temperature, but also to the ... | 2007 | 18284742 |
| contrasting nuclear and cytoplasmic exchanges between phylogenetically distant oak species (quercus suber l. and q. ilex l.) in southern france: inferring crosses and dynamics. | gene flow is particularly frequent in the genus quercus (oaks), especially between closely related species. we focus here on quercus ilex and the cork-producing quercus suber, which occasionally hybridize although they are phylogenetically markedly separated. morphological observations were combined with both allozymic and chloroplastic diagnostic markers to characterize hybridization and introgression and to infer their dynamics in two french regions (french catalonia and provence), which are s ... | 2009 | 19228328 |
| detection of hybrids in nature: application to oaks (quercus suber and q. ilex). | powerful and accurate detection of first-generation (f1) hybrids and backcrosses in nature is needed to achieve a better understanding of the function and dynamics of introgression. to document the frequency of ongoing interspecific gene exchange between two mediterranean evergreen oaks, the cork oak (quercus suber) and the holm oak (q. ilex), we analyzed 1487 individuals originating from across the range of the two species using eight microsatellite loci and two bayesian clustering approaches ( ... | 2009 | 19240752 |
| genetic transformation of cork oak (quercus suber l.) for herbicide resistance. | the bar gene was introduced into the cork oak genome. cork oak embryogenic masses were transformed using the agrobacterium strain agl1 which carried the plasmid pbinubibar. this vector harbours the genes, nptii and bar, the latter under control of the maize ubiquitin promoter. the transgenic embryogenic lines were cryopreserved. varying activities of phosphinothricin acetyl transferase were detected among the lines, which carried 1-4 copies of the insert. molecular and biochemical assays confirm ... | 2009 | 19543858 |
| ancient and current gene flow between two distantly related mediterranean oak species, quercus suber and q. ilex. | quercus suber and q. ilex are distantly related and their distributions partially overlap. they hybridize occasionally, but the complete replacement of q. suber chloroplast dna (cpdna) by that of q. ilex was identified in two specific geographical areas. the objective of this study was to determine whether the contrasting situation reflected current or recent geographical interspecies gene flow variation or was the result of ancient introgression. | 2009 | 19556263 |
| land use practices and ectomycorrhizal fungal communities from oak woodlands dominated by quercus suber l. considering drought scenarios. | oak woodlands in the mediterranean basin have been traditionally converted into agro-silvo-pastoral systems and exemplified sustainable land use in europe. in portugal, in line with the trend of other european countries, profound changes in management options during the twentieth century have led to landscape simplification. landscapes are dynamic and the knowledge of future management planning combining biological conservation and soil productivity is needed, especially under the actual scenari ... | 2010 | 19575241 |
| relevance of genetics for conservation policies: the case of minorcan cork oaks. | marginal populations of widely distributed species can be of high conservation interest when they hold a significant or unique portion of the genetic diversity of the species. however, such genetic information is frequently lacking. here the relevance of genetic surveys to develop efficient conservation strategies for such populations is illustrated using cork oak (quercus suber) from minorca (balearic islands, spain) as a case study. cork oak is highly endangered on the island, where no more th ... | 2009 | 19671575 |
| antioxidant and biological properties of bioactive phenolic compounds from quercus suber l. | phenolic compounds, namely, hydrolyzable tannins and low molecular weight phenolic compounds, were isolated and purified from portuguese cork from quercus suber l. some of these compounds were studied to evaluate their antioxidant activity, including free-radical scavenging capacity (dpph method) and reducing capacity (frap method). all compounds tested showed significant antioxidant activity, namely, antiradical and reducing properties. the antiradical capacity seemed to increase with the prese ... | 2009 | 19888728 |
| transfer of 238u, 230th, 226ra, and 210pb from soils to tree and shrub species in a mediterranean area. | the soil-to-plant transfer factors of natural uranium isotopes ((238)u and (234)u), (230)th, (226)ra, and (210)pb were studied in a disused uranium mine located in the extremadura region in the south-west of spain. the plant samples included trees (quercus ilex, quercus suber, and eucalyptus cameldulensis) and one shrub (cytisus multiflorus). all of them are characteristic of mediterranean environments. the activity concentrations in leaves and fruit were determined for the tree species at diffe ... | 2010 | 20153657 |
| sensitivity to zinc of mediterranean woody species important for restoration. | heavy metals have increased in natural woodlands and shrublands over the last several decades as a consequence of anthropogenic activities. however, our knowledge of the effects of these elements on woody species is scarce. in this study, we examined the responses of six mediterranean woody species to increasing levels of zinc in hydroponic culture and discussed the possible implications for the restoration of contaminated sites. the species used, pinus pinea l., pinus pinaster ait., pinus halep ... | 2010 | 20189221 |
| drought-induced photosynthetic inhibition and autumn recovery in two mediterranean oak species (quercus ilex and quercus suber). | responses of leaf water relations and photosynthesis to summer drought and autumn rewetting were studied in two evergreen mediterranean oak species, quercus ilex spp. rotundifolia and quercus suber. the predawn leaf water potential (ψ(lpd)), stomatal conductance (gs) and photosynthetic rate (a) at ambient conditions were measured seasonally over a 3-year period. we also measured the photosynthetic response to light and to intercellular co₂ (a/ppfd and a/c(i) response curves) under water stress ( ... | 2010 | 20571151 |
| impact of wildfire return interval on the ectomycorrhizal resistant propagules communities of a mediterranean open forest. | ectomycorrhizal (ecm) fungi, in particular their spores and other resistant propagules, play an important role in secondary succession processes that facilitate regeneration after disturbance events. in this study, the effects of high and low wildfire frequencies (respectively short and long fire return intervals) on the resistant propagules communities (rpcs) of a mediterranean open pine forest were compared. soil samples were collected in four mountain sites with different fire return interval ... | 2010 | 20943174 |
| [pollen analysis from two littoral marshes (bourdim and garaat el-ouez) in the el-kala wet complex (north-east algeria). lateglacial and holocene history of algerian vegetation]. | the study of two pollen sequences from el-kala marshes allowed the reconstruction of the regional vegetation history supported by eight radiocarbon dates. pollen assemblages from bourdim site were dominated by local input of alnus and salix, while regional vegetation was characterized by scattered quercus suber forests with a well-developed erica arborea matorral. while the vegetation dynamics recorded at bourdim is recent (late holocene), the majority of the pollen diagram from garaat el-ouez i ... | 2010 | 20965444 |
| Emission factors from residential combustion appliances burning Portuguese biomass fuels. | Smoke from residential wood burning has been identified as a major contributor to air pollution, motivating detailed emission measurements under controlled conditions. A series of experiments were performed to compare the emission levels from two types of wood-stoves to those of fireplaces. Eight types of biomass were burned in the laboratory: wood from seven species of trees grown in the Portuguese forest (Pinus pinaster, Eucalyptus globulus, Quercus suber, Acacia longifolia, Quercus faginea, O ... | 2011 | 22027805 |
| investigating aspergillus nidulans secretome during colonisation of cork cell walls. | cork, the outer bark of quercus suber, shows a unique compositional structure, a set of remarkable properties, including high recalcitrance. cork colonisation by ascomycota remains largely overlooked. herein, aspergillus nidulans secretome on cork was analysed (2de). proteomic data were further complemented by microscopic (sem) and spectroscopic (atr-ftir) evaluation of the colonised substrate and by targeted analysis of lignin degradation compounds (uplc-hrms). data showed that the fungus forme ... | 2014 | 24316358 |
| fungal biodegradation of anthracene-polluted cork: a comparative study. | the efficiency of cork waste in adsorbing aqueous polycyclic aromatic hydrocarbons (pahs) has been previously reported. biodegradation of contaminated cork using filamentous fungi could be a good alternative for detoxifying cork to facilitate its final processing. for this purpose, the degradation efficiency of anthracene by three ligninolytic white-rot fungi (phanerochaete chrysosporium, irpex lacteus and pleurotus ostreatus) and three non-ligninolytic fungi which are found in the cork itself ( ... | 2016 | 26540209 |
| antifungal activity of acetone extracts from punica granatum l., quercus suber l. and vicia faba l. | human and animal mycoses become more frequent and more resistant to traditional treatments. in this work, we tested the in vitro antifungal activity of acetonic extracts of punica granatum l., quercus suber l. and vicia faba l. against seven pathogen fungi and the in vivo antifungal activity against candida albicans and trichophyton mentagrophytes. the phytochemical screening was also carried out and showed that the extracts contained mainly proanthocyanidins. other polyphenols were also present ... | 2017 | 27856170 |
| a novel metallothionein gene from a mangrove plant kandelia candel. | a new metallothionein (mt) gene was cloned from kandelia candel, a mangrove plant with constitutional tolerance to heavy metals, by rapid amplification of cdna ends and named kmt, which is composed of two exons and one intron. the full length of kmt cdna was 728 bp including 121 bp 5' noncoding domain, 240 bp open reading frame and 384 bp 3' termination. the coding region of kmt represented a putative 79 amino acid protein with a molecular weight of 7.75 kda. at each of the amino- and carboxy-te ... | 2012 | 22711547 |
| quantitative rt-pcr analysis of differentially expressed genes in quercus suber in response to phytophthora cinnamomi infection. | cdna-aflp methodology was used to gain insight into gene fragments differentially present in the mrna profiles of quercus suber roots infected with zoospores of phytophthora cinnamomi at different post challenge time points. fifty-three transcript-derived fragments (tdfs) were identified and sequenced. six candidate genes were selected based on their expression patterns and homology to genes known to play a role in defence. they encode a cinnamyl alcohol dehydrogenase2 (qscad2), a protein disulp ... | 2014 | 25392784 |
| anatomy and development of the endodermis and phellem of quercus suber l. roots. | quercus suber l. has been investigated with special attention to the stem bark and its cork formation layer, but excluding the roots. roots are the location of infection by pathogens such as phytophthora cinnamomi responsible for the tree's sudden death. it is widely accepted that suberin establishes boundaries within tissues, serves as a barrier against free water and ion passage, and works as a shield against pathogen attacks. we followed the suberization of young secondary roots of cork oak. ... | 2013 | 23551860 |
| impact of leaf traits on temporal dynamics of transpired oxygen isotope signatures and its impact on atmospheric vapor. | oxygen isotope signatures of transpiration (δ e ) are powerful tracers of water movement from plant to global scale. however, a mechanistic understanding of how leaf morphological/physiological traits effect δ e is missing. a laser spectrometer was coupled to a leaf-level gas-exchange system to measure fluxes and isotopic signatures of plant transpiration under controlled conditions in seven distinct species (fagus sylvatica, pinus sylvestris, acacia longifolia, quercus suber, coffea arabica, pl ... | 2017 | 28149303 |
| mutagenicity assessment of aerosols in emissions from wood combustion in portugal. | polycyclic aromatic hydrocarbon (pah) extracts of fine particles (pm(2.5)) collected from combustion of seven wood species and briquettes were tested for mutagenic activities using ames test with salmonella typhimurium ta98 and ta100. the woods were pinus pinaster (maritime pine), eucalyptus globulus (eucalypt), quercus suber (cork oak), acacia longifolia (golden wattle), quercus faginea (portuguese oak), olea europea (olive), and quercus ilex rotundifolia (holm oak). burning experiments were do ... | 2012 | 22512998 |
| rna-seq and gene network analysis uncover activation of an aba-dependent signalosome during the cork oak root response to drought. | quercus suber (cork oak) is a west mediterranean species of key economic interest, being extensively explored for its ability to generate cork. like other mediterranean plants, q. suber is significantly threatened by climatic changes, imposing the need to quickly understand its physiological and molecular adaptability to drought stress imposition. in the present report, we uncovered the differential transcriptome of q. suber roots exposed to long-term drought, using an rna-seq approach. 454-sequ ... | 2015 | 26793200 |
| evaluation of the presence of arabinogalactan proteins and pectins during quercus suber male gametogenesis. | quercus suber (cork oak) is a dominant tree of the fagaceae in forests of the south-west iberian peninsula. it is monoecious with a long progamic phase that provides a comprehensive system for comparative studies in development and sexual reproduction. in this study the distribution of arabinogalactan protein (agps) and pectin epitopes in anthers of q. suber was assessed to map these hydroxyproline-rich glycoproteins and the galacturonate-rich acidic polysaccharides during pollen development. me ... | 2015 | 25452249 |
| mycorrhizal synthesis between lactarius deliciosus and arbutus unedo l. | arbutoid mycorrhizae were synthesized in vitro between arbutus unedo l. and two isolates of lactarius deliciosus. the fungal isolates were obtained from sporocarps collected under pinus sylvestris and in a mixed forest stand of quercus suber and pinus pinea. synthesis tubes filled with a mixture of sterilized peat, vermiculite, and perlite imbibed with nutrient solution were used. two inoculation methods using solid and liquid media were tested. shoots from an adult selected clone of a. unedo we ... | 2016 | 26215114 |
| stomatal patchiness in mediterranean evergreen sclerophylls : phenomenology and consequences for the interpretation of the midday depression in photosynthesis and transpiration. | midday depression of net photosynthesis and transpiration in the mediterranean sclerophylls arbutus unedo l. and quercus suber l. occurs with a depression of mesophyll photosynthetic activity as indicated by calculated carboxylation efficiency (ce) and constant diurnal calculated leaf intercellular partial pressure of co2 (ci). this work examines the hypothesis that this midday depression can be explained by the distribution of patches of either wide-open or closed stomata on the leaf surface, i ... | 1992 | 24178151 |
| effects of temperature at constant air dew point on leaf carboxylation efficiency and co2 compensation point of different leaf types. | the effect of temperature on photosynthesis at constant water-vapor pressure in the air was investigated using two sclerophyll species, arbutus unedo and quercus suber, and one mesophytic species, spinacia oleracea. photosynthesis and transpiration were measured over a range of temperatures, 20-39° c. the external concentration of co2 was varied from 340 μbar to near co2 compensation. the initial slope (carboxylation efficiency, ce) of the photosynthetic response to intercellular co2 concentrati ... | 1985 | 24241315 |
| unravelling the distinct crystallinity and thermal properties of suberin compounds from quercus suber and betula pendula outer barks. | the main purpose of this study was to investigate the potential of suberin (a naturally occurring aromatic-aliphatic polyester ubiquitous to the vegetable realm) as a renewable source of chemicals and, in particular, to assess their physical properties. a comparison between cork and birch suberin fragments obtained by conventional depolymerisation processes (hydrolysis or methanolysis) is provided, focusing essentially on their thermal and crystallinity properties. it was found that suberin frag ... | 2016 | 27632951 |
| photosynthesis of quercus suber is affected by atmospheric nh3 generated by multifunctional agrosystems. | montados are evergreen oak woodlands dominated by quercus species, which are considered to be key to biodiversity conservation and ecosystem services. this ecosystem is often used for cattle breeding in most regions of the iberian peninsula, which causes plants to receive extra nitrogen as ammonia (nh(3)) through the atmosphere. the effect of this atmospheric nh(3) (nh(3atm)) on ecosystems is still under discussion. this study aimed to evaluate the effects of an nh(3atm) concentration gradient d ... | 2013 | 24150034 |
| suberized cell walls of cork from cork oak differ from other species. | plants have suberized cells that act as protective interfaces with the environment or between different plant tissues. a lamellar structure of alternating dark and light bands has been found upon transmission electron microscopy (tem) observation of cork cells and considered a typical feature of the suberized secondary wall. we observed cork cells from periderms of quercus suber, quercus cerris, solanum tuberosum, and calotropis procera by tem after uranyl acetate and lead citrate staining. a la ... | 2010 | 20804640 |
| ultrastructural observations reveal the presence of channels between cork cells. | the ultrastructure of phellem cells of quercus suber l. (cork oak) and calotropis procera (ait) r. br. were analyzed using electron transmission microscopy to determine the presence or absence of plasmodesmata (pd). different types of q. suber cork samples were studied: one year shoots; virgin cork (first periderm), reproduction cork (traumatic periderm), and wet cork. the channel structures of pd were found in all the samples crossing adjacent cell walls through the suberin layer of the seconda ... | 2009 | 19811698 |
| cryphonectria naterciae: a new species in the cryphonectria-endothia complex and diagnostic molecular markers based on microsatellite-primed pcr. | in a recent study intended to assess the distribution of cryphonectria parasitica in portugal, 22 morphologically atypical orange isolates were collected in the midwestern regions. eleven isolates were recovered from castanea sativa, in areas severely affected by chestnut blight and eleven isolates from quercus suber in areas with cork oak decline. these isolates were compared with known c. parasitica and cryphonectria radicalis isolates using an integrated approach comprising morphological and ... | 2011 | 21872182 |
| molecular organization of the 25s-18s rdna igs of fagus sylvatica and quercus suber: a comparative analysis. | the 35s ribosomal dna (rdna) units, repeated in tandem at one or more chromosomal loci, are separated by an intergenic spacer (igs) containing functional elements involved in the regulation of transcription of downstream rrna genes. in the present work, we have compared the igs molecular organizations in two divergent species of fagaceae, fagus sylvatica and quercus suber, aiming to comprehend the evolution of the igs sequences within the family. self- and cross-hybridization fish was done on re ... | 2014 | 24893289 |
| three new species of collembola from soils of mediterranean cork-oak forests of sicily (italy). | three new species of soil collembola from cork-oak (quercus suber) forests located in eastern sicily (italy) are described neonaphorura alicatai sp. nov., friesea guarinoi sp. nov. and arrhopalites antonioi sp. nov.. | 2013 | 26266301 |