A revision ofTaraxacum sect.Piesis (Compositae)

On the basis of allozyme and cultivation data, and of additional herbarium material, a taxonomic and nomenclatural revision ofTaraxacum sect.Piesis A.J. Richards exKirschner et?těpánek is provided. The section is made up of halophilous, sexually reproducing taxa. InT. stenocephalum Boiss. etKotschy,T. pindicum Kirschner et?těpánek, sp. nov., andT. perenne Kirschner et?těpánek, sp. nov., a tetraploid chromosome number has been recorded, representing the only known case of sexuality at the tetraploid level in the genus. The complex ofT. stenocephalum, includes some geographically and morphologically extreme populations treated as subspecies: subsp.gumusanicum (Soest)Kirschner et?těpánek, comb. nov., subsp.magnum Kirschner et?těpánek, subsp. nov., and subsp.daralagesicum (Schischk.)Kirschner et?těpánek, comb. nov. In addition toT. bessarabicum (Hornem.)Hand.-Mazz., a widely distributed Eurasian species,T. stenocephalum, a complex centred in Transcaucasia and Anatolia, andT. pachypodum H. Lindb., a North African endemic, four new species are described:T. salsum Kirschner et?těpánek, sp. nov., a diploid endemic confined to E Crimea,T. perenne Kirschner et?těpánek, sp. nov., a tetraploid sexual species known only from SW Crimea,T. pindicum Kirschner et?těpánek, sp. nov., a remarkable tetraploid endemic to the Pindos Mts., Greece, andT. salsitatis Kirschner, ?těpänek etYirdirimli, sp. nov., an Anatolian diploid species. Furthermore, a hybrid betweenT. salsum andT. bessarabicum from Crimea (documented on the basis of allozyme data elsewhere) is given a binomial,T. xmesohalobium Kirschner et?těpánek, nothosp. nov.     

Holocene anthropogenic landscapes in the Balkans: the palaeobotanical evidence from southwestern Bulgaria

Palaeoecological reconstructions from the region of southwestern Bulgaria were used for inferring the human impact on the vegetation and landscape during the last 8 millennia. They are based on data from pollen analyses of lakes and peat-bogs, plant macrofossils, archaeobotanical finds and radiocarbon dating. During the early Holocene, after 7900?cal. b.p. (5950?cal. b.c.) the climate changed to cooler summers, milder winters and higher precipitation resulting in the formation of a coniferous belt dominated by Pinus sp. and Abies alba. These favorable environmental pre-conditions had a positive influence on the Neolithisation of the Balkans after the 8200?cal. b.p. (6250?cal. b.c.) cold event, which caused drought in the Eastern Mediterranean. Direct evidence from wood charcoal records from the Neolithic settlement layers in the study area shows a slight modification of the surrounding woodlands and an increase of the light-demanding components, probably expressed through larger forest border zones and thinning out of the wood stands. The increase in the number of settlements in the valleys of southwestern Bulgaria intensified the human activity visible in the palaeobotanical record from 6950?cal. b.p. (5000?cal. b.c.) onwards. Between ca. 5700–5100?cal. b.p. (3800–3200?cal. b.c.) signs of anthropogenic influence on the vegetation are virtually absent. The intensity of human impact increased notably after 3200?cal. b.p. (1400–1250?cal. b.c., approx. Late Bronze Age), documented by a rise of pollen anthropogenic indicators. The final transformations in the natural forest cover after 2750?cal. b.p. (800?cal. b.c. onset of the Iron Age) marked the reduction of the coniferous forests dominated by Abies alba and Pinus sp. and the expansion of Fagus sylvatica and Picea abies. These vegetation changes are contemporaneous with increase of the palaeofire activities and the next peak of anthropogenic indicators. The changes in the landscape during the Roman period and the medieval period reflect regional environmental features and were forced by the diversification of anthropogenic activity.     

Coleanthus subtilis (Tratt.)Seidl. in the Amur Basin

The history of the discovery and results of authentic investigations ofColeanthus subtilis (Tratt.)Seidl. in the Amur Basin are presented. Distrubution, ecological requirements, morphology of particular organs, dispersal on the riverbanks, and associated vascular plants ofColeanthus subtilis are described in detail.     

l-Arabinose/d-galactose 1-dehydrogenase of Rhizobium leguminosarum bv. trifolii characterised and applied for bioconversion of l-arabinose to l-arabonate with Saccharomyces cerevisiae

Four potential dehydrogenases identified through literature and bioinformatic searches were tested for l-arabonate production from l-arabinose in the yeast Saccharomyces cerevisiae. The most efficient enzyme, annotated as a d-galactose 1-dehydrogenase from the pea root nodule bacterium Rhizobium leguminosarum bv. trifolii, was purified from S. cerevisiae as a homodimeric protein and characterised. We named the enzyme as a l-arabinose/d-galactose 1-dehydrogenase (EC 1.1.1.-), Rl AraDH. It belongs to the Gfo/Idh/MocA protein family, prefers NADP⁺ but uses also NAD⁺ as a cofactor, and showed highest catalytic efficiency (k _cat/K _m) towards l-arabinose, d-galactose and d-fucose. Based on nuclear magnetic resonance (NMR) and modelling studies, the enzyme prefers the α-pyranose form of l-arabinose, and the stable oxidation product detected is l-arabino-1,4-lactone which can, however, open slowly at neutral pH to a linear l-arabonate form. The pH optimum for the enzyme was pH 9, but use of a yeast-in-vivo-like buffer at pH 6.8 indicated that good catalytic efficiency could still be expected in vivo. Expression of the Rl AraDH dehydrogenase in S. cerevisiae, together with the galactose permease Gal2 for l-arabinose uptake, resulted in production of 18 g of l-arabonate per litre, at a rate of 248 mg of l-arabonate per litre per hour, with 86 % of the provided l-arabinose converted to l-arabonate. Expression of a lactonase-encoding gene from Caulobacter crescentus was not necessary for l-arabonate production in yeast.     

LignicolousHyphomycetes from Czechoslovakia 1.Brachysporium

Four species of the genusBrachysporium Sacc. emend.Mason etHughes are treated in this paper from Czechoslovakia:B. nigrum (Link)Hughes,B. obovatum (Berk.)Sacc. and two new species,B. abietinum Hol.-Jech. andB. brevius Hol.-Jech.     

Chromosome counts of some Cuban Angiosperms

Chromosome numbers are reported for 14 species collected in Cuba. The first chromosome records are reported forAlbizzia cubana Britton etWilson (2n=26),Atkinsia cubensis (Britton etWilson)Howard (2n=26),Caesalpinia violacea (Mill.)Standl. (2n=24),Colubrina ferruginosa Brongn. (2n=24). Chromosome numbers of the following species were confirmed:Albizzia lebbeck (L.)Benth. (2n=26),Canavalia maritima (Aubl.)Thouars (2n=22),Casuarina equisetifolia Forst. (2n=18),Cedrela mexicana M.J. Roem. (2n=56),Delonix regia (Bojer)Raf. (2n=28),Guazuma tomentosa H.B.K. (2n=16),Lysiloma bahamense Benth. (2n=26),L. latisiliqua (L.)Benth. (2n=26),Samanea saman (Jacq.)Merrill (2n=26),Thespesia populnea (L.)Soland (2n=26).     

Effects of Dietary Zinc and l-Arginine Supplementation on Total Antioxidants Capacity, Lipid Peroxidation, Nitric Oxide, Egg Weight, and Blood Biochemical Values in Japanase Quails

The aim of this study was to evaluate effects of dietary zinc and l-arginine supplementation on blood total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), some blood chemistry parameters, and egg weights of laying quails. Three groups of Japanese quails were fed with a diet containing l-arginine (5 mg/kg), zinc (60 mg/kg), and normal basal diet (control) for 30 days. TAC, lipid peroxidation, and biochemical analysis were performed in the blood of animals. l-Arginine and zinc supplementation improved TAC and reduced MDA concentrations compared to the control (P?<?0.05). In comparison to the control, blood NO concentrations were increased by l-arginine (P?<?0.01) and zinc treatment (P?<?0.05). Both zinc (P?<?0.001) and l-arginine (P?<?0.01) supplementation significantly increased egg weight in laying quails. Some of the blood chemistry parameters were also altered by the treatment of l-arginine and zinc supplementation. No difference was found in blood albumin and creatinine levels among the groups. Blood glucose (P?=?0.833) and total protein (P?=?0.264) levels in control and l-arginine-treated groups were found to be similar. Glucose and total protein levels were decreased in zinc-supplemented animals compared to the control and l-arginine groups (P?<?0.05). No difference was found in triglyceride levels between control and zinc-applied groups (P?=?0.197). However, l-arginine treatment reduced the blood triglyceride levels compared to the control (P?<?0.05). In conclusion, l-arginine and zinc supplementation could be beneficial and effective for decreasing oxidative stress, boosting antioxidant capacity, and improving egg weight in the blood of the animals.     

Backbone and side-chain 1H, 15N and 13C assignment of apo- and imipenem-acylated l,d-transpeptidase from Bacillus subtilis

The d,d-transpeptidase activity of Penicillin Binding Proteins (PBPs) is essential to maintain cell wall integrity. PBPs catalyze the final step of the peptidoglycan synthesis by forming 4 → 3 cross-links between two peptide stems. Recently, a novel β-lactam resistance mechanism involving l,d-transpeptidases has been identified in Enterococcus faecium and Mycobacterium tuberculosis. In this resistance pathway, the classical 4 → 3 cross-links are replaced by 3 → 3 cross-links, whose formation are catalyzed by the l,d-transpeptidases. To date, only one class of the entire β-lactam family, the carbapenems, is able to inhibit the l,d-transpeptidase activity. Nevertheless, the specificity of this inactivation is still not understood. Hence, the study of this new transpeptidase family is of considerable interest in order to understand the mechanism of the l,d-transpeptidases inhibition by carbapenems. In this context, we present herein the backbone and side-chain ¹H, ¹⁵N and ¹³C NMR assignment of the l,d-transpeptidase from Bacillus subtilis (Ldt_Bs) in the apo and in the acylated form with a carbapenem, the imipenem.     

Characterization of uptake and release processes ford- andl-aspartate in primary cultures of astrocytes and cerebellar granule cells

The uptake ofl-andd-aspartate was studied in astrocytes cultured from prefrontal cortex and in granule cells cultured from cerebellum. A high affinity uptake system forl- andd-aspartate was found in both cell types, and the two stereoisomers exhibited essentially the sameK _m - andV _max -values in bouth astrocytes (l-aspartate:K _m 77 μM;V _max 11.8 nmol×min^?1×mg^?1;d-aspartate:K _m 83 μM;V _max 14.0 nmol×min^?1×mg^?1) and granule cells (l-aspartate:K _m 32 μM;V _max 2.8 nmol ×min^?1×mg^?1;d-aspartate:K _m 26 μM;V _max 3.0 nmol×min^?1×mg^?1). To investigate whetherl-glutamate,l-aspartate andd-aspartate use the same uptake system a detailed kenetic analysis was performed. The uptake kinetics of each one of the three amino acids was studied in the presence of the two other amino acids, and no essential differences between the uptake characteristics of the amino acids were found. In addition to the uptake studies the release ofD-aspartate from cerebellar granule cells was investigated and compared withl-glutamate release. A Ca²⁺-dependent, K⁺-induced release was found for both amino acids.     

New internally structured decapod microcoprolites from Germany (Late Triassic/Early Miocene), Southern Spain (Early/Middle Jurassic) and Portugal (Late Jurassic): Taxonomy, palaeoecology and evolutionary implications

Fossil faecal pellets with internal structures are described from non-marine environments for the first time. In the Late Triassic Lehrberg Beds (Middle Keuper, Carnian) of Germany, the oldest stratigraphic record of the form genusHelicerina Brönnimann &Masse,Helicerina keuperina Seegis n. sp., occurs.Favreina kalankyra Ebli from the Norian Hauptdolomit Formation is also attributed to this genus. Another new speciesof Helicerina, H. ruttei Schweigert n. sp., is described from the Early Miocene calcareous freshwater tufas of Southern Germany. It is attributed to the brachyuran freshwater crabProballaya quenstedti (Zittel) which occurs abundantly at the same locality. Hence, the coprolite genusHelicerina is the product of brachyuran decapods or their Triassic ancestors, and not of anomuran decapods as thought before. From younger Early to Middle Jurassic pelagic ferrugineous limestones of the Subbetic area (Southern Spain), the new speciesFavreina belandoi Fels n. sp. is described besidesHelicerina siciliana Senowbari-Daryan, Schäfer &Catalano, and the better known speciesPalaxius salataensis Brönnimann, Cros &Zaninetti. The number of canals withinFavreina belandoi varies but is clearly correlated with different ontogenetic stages of the same producer. From the Late Jurassic of Portugal, the new speciesPetalina hexalunulata Leinfelder n. gen. n. sp. is reported. It co-occurs withFavreina prusensis (Paréjas). The new genusPetalina is distinct fromFavreina by its hemispherical cross sections of the canals. In Portugal, both species are restricted to intrajurassic marine karstic fissures of the reefal Ota Limestone.     

l-leucine, l-methionine, and l-phenylalanine share a Na+/K+-dependent amino acid transporter in shrimp hepatopancreas

Hepatopancreatic brush border membrane vesicles (BBMV), made from Atlantic White shrimp (Litopenaeus setiferus), were used to characterize the transport properties of ³H-l-leucine influx by these membrane systems and how other essential amino acids and the cations, sodium and potassium, interact with this transport system. ³H-l-leucine uptake by BBMV was pH-sensitive and occurred against transient transmembrane concentration gradients in both Na⁺- and K⁺-containing incubation media, suggesting that either cation was capable of providing a driving force for amino acid accumulation. ³H-l-leucine uptake in NaCl or KCl media were each three times greater in acidic pH (pH 5.5) than in alkaline pH (pH 8.5). The essential amino acid, l-methionine, at 20 mM significantly (p < 0.0001) inhibited the 2-min uptakes of 1 mM ³H-l-leucine in both Na⁺- and K⁺-containing incubation media. The residual ³H-l-leucine uptake in the two media were significantly greater than zero (p < 0.001), but not significantly different from each other (p > 0.05) and may represent an l-methionine- and cation-independent transport system. ³H-l-leucine influxes in both NaCl and KCl incubation media were hyperbolic functions of [l-leucine], following the carrier-mediated Michaelis–Menten equation. In NaCl, ³H-l-leucine influx displayed a low apparent K _M (high affinity) and low apparent J _max, while in KCl the transport exhibited a high apparent K _M (low affinity) and high apparent J _max. l-methionine or l-phenylalanine (7 and 20 mM) were competitive inhibitors of ³H-l-leucine influxes in both NaCl and KCl media, producing a significant (p < 0.01) increase in ³H-l-leucine influx K _M, but no significant response in ³H-l-leucine influx J _max. Potassium was a competitive inhibitor of sodium co-transport with ³H-l-leucine, significantly (p < 0.01) increasing ³H-l-leucine influx K _M in the presence of sodium, but having negligible effect on ³H-l-leucine influx J _max in the same medium. These results suggest that shrimp BBMV transport ³H-l-leucine by a single l-methionine- and l-phenylalanine-shared carrier system that is enhanced by acidic pH and can be stimulated by either Na⁺ or K⁺ acting as co-transport drivers binding to shared activator sites.     

New chromosome numbers inTaraxacum with reference to SAT-chromosomes

Chromosome numbers of eight agamospermousTaraxacum microspecies are reported for the first time:T hypanicum Tzvel. [sect.Dioszegia (Heuff.) Heuff.,T. neosivaschicum Tzvel. [sect.Palustria (Lindb, fil.)Dahlst.],T. pseudohoppeanum Kirschner et?těpánek (sect.Erythrocarpa Dahlst.),T. schroeterianum H.-M. (sect.Rhodocarpa Van Soest),T. marmottae C.E. Sonck,T. lambinonii Van Soest [sect.Erythrosperma (Lindb. fil.)Dahlst.],T. zermattense Dahlst, andT. magnoobliquum Van Soest (taxa of uncertain classification). All these polyploid microspecies have satellite chromosomes in their karyotypes. Advanced karyological characters were found in sect.Dioszegia, hitherto regarded as a primitive section ofTaraxacum: triploidy in agamospermousT. hypanicum Tzvel. and satellite chromosomes as in this taxon, as in two diploid sexualsT. serotinum (W. et K.)Poiret andT. haussknechtii Uechtr. The results presented are compared to the literature data.     

Scanning electron microscopic study of anamorphs of someBasidiomycetes in culture

The anamorphs in cultures ofLepista nuda (Bull.:Fr.)Cooke,Coprinus comatus (Müll.:Fr.)S.F. Gray,Fistulina hepatica Sohaeff.:Fr.,Pholiota adiposa (Fr.)Kumm. andAsterophora lycoperdoides (Bull.)S.F. Gray, an imperfect state ofNyctalis lycoperdoides (Bull.)Schroet., were studied by scanning electron microscopy. Arthroconidia were described inLepista nuda for the first time. Examination of the fine structure of dendroid forms inCoprinus comatus revealed why those structures were not propagative.     

Verbeitung einiger seltenen und subendemischen Arten der griechischen Flora mit taxonomischen und chorologischen Betrachtungen

The taxa very rare in Greece,Gentianella bulgarica (Velen.)J. Holub andPrimula elatior (L.)Hill subsp.intricata (Gren. etGodron)Lüdi Balkan-South Carpathian and mountain subendemic taxon of South and South-Central Europe also the oreophytesGentiana asclepidaea L. andAndrosace villosa L. rare in Greece at high altitudes endemic species of Central Europe and arcto-alpic element both extending South as far as Central Italy and Central Greece as well as the relatively rare species in Greece,Crocus biflorus Mill. which exists in South Europe from Sicily and eastwards and finally four otherIridaceae, i.e.: the South Balkan Asia-Minor subendemic speciesCrocus olivieri Gay andC. pulchellus Herbert, the South Balkan endemic speciesC. veluchensis Herbert and the Mediterranean and mostly East-para-mediterranean subendemic speciesHermodactylus tuberosus (L.)Miller are reported and investigated. However new habitats and records in the Greek area of the investigated species are given, their distribution is discussed, while the existence of the taxa most rare in GreecePrimula elatior (L.)Hill subsp.intricata (Gren. etGodron)Lüdi inHegi,Gentianella bulgarica (Velen.)J. Holub,Gentiana asclepiadea L.,Androsace villosa L. andCrocus biflorus Mill. are presented in the form of a dot map and thus the southernmost limits of their spreading in the Balkan peninsula or in S.E. Europe are elucidated.     

ClassAsteretea tripolium on the territory of the former USSR and Mongolia

Higher syntaxa of the classAsteretea tripolium are reviewed. This class covers plant communities of the Euro-Asian continent on low- and medium-salinized soils with medium moisture conditions where perennial herbaceous plants (hemicryptophytes) of non-succulent character prevail. On the territory of the former USSR and Mongolia, the classAsteretea tripolium is represented by the following orders:Glauco-Puccinellietalia Beeftink etWesthoff inBeeftink 1962,Cirsietalia esculenti Mirkin etV. Golub exV. Golub ord. novus,Scorzonero-Juncetalia gerardii Vicherek 1973,Halerpestetalia Mirkin et al. exV. Golub ord. novus,Artemisio santonicae-Limonietalia gmelinii V. Golub etV. Solomakha 1988,Suaedetalia corniculatae V. Golub ord. novus. Superspecies and aggregations of species are used for the diagnosis of higher syntaxa.     

d-Amino Acid-Induced Expression of d-Amino Acid Oxidase in the Yeast Schizosaccharomyces pombe

We investigated d-amino acid oxidase (DAO) induction in the popular model yeast Schizosaccharomyces pombe. The product of the putative DAO gene of the yeast expressed in E.?coli displayed oxidase activity to neutral and basic d-amino acids, but not to an l-amino acid or acidic d-amino acids, showing that the putative DAO gene encodes catalytically active DAO. DAO activity was weakly detected in yeast cells grown on a culture medium without d-amino acid, and was approximately doubled by adding d-alanine. The elimination of ammonium chloride from culture medium induced activity by up to eight-fold. l-Alanine also induced the activity, but only by about half of that induced by d-alanine. The induction by d-alanine reached a maximum level at 2?h cultivation; it remained roughly constant until cell growth reached a stationary phase. The best inducer was d-alanine, followed by d-proline and then d-serine. Not effective were N-carbamoyl-d,l-alanine (a better inducer of DAO than d-alanine in the yeast Trigonopsis variabilis), and both basic and acidic d-amino acids. These results showed that S. pombe DAO could be a suitable model for analyzing the regulation of DAO expression in eukaryotic organisms.     

Chromosome numbers in selectedHieracium species in the Krkonoše Mts. (the West Sudeten)

Chromosome numbers are given of 15 species of the genusHieracium L. s. str., representing seven species groups (in the sense of Flora Europaea, roughly corresponding to Zahn's “species principales”) from the Krkono?e Mts., N. Bohemia and SW Poland. For the first time chromosome numbers are reported forH. melanocephalum Tausch (2n=27),H. tubulosum Tausch (2n=36),H. schustleri Zlatník (2n=36),H. fritzei F. Schultz (2n=27),H. rohlenae Zlatník (2n=27),H. nigrescens Willd. (2n=36),H. decipiens Tausch (2n=36),H. atrellum Juxip inSchischkin etBobrov (2n=27),H. subnigrescens (Fries exNorrlin)Dahlst. (2n=36),H. sudeticum Sternberg (2n=36),H. pedunculare Tausch (2n=36),H. glandulosodentatum Uechtr. (2n=36),H. wimmeri Uechtr. (2n=27). InHieracium alpinum L. s. str. the number 2n=27 has been confirmed. The results show a high proportion of tetraploid taxa; no diploids have been found.