Morphological and molecular characterization of two ITS groups of <Emphasis Type="Italic">Erysiphe</Emphasis> (Erysiphales) occurring on <Emphasis Type="Italic">Syringa</Emphasis> and <Emphasis Type="Italic">Ligustrum</Emphasis> (Oleaceae)

ITS sequences determined for 53 Erysiphe specimens on Syringa and Ligustrum collected in Europe, East Asia, and North and South America were divided into two ITS groups, S and K types. Phylogenetic analysis showed that these two ITS types do not share a common ancestor and form separate clades. The K type on Ligustrum was identified as Erysiphe ligustri based on the three-dimensional branching pattern of appendages. Morphological observations showed that there are some morphological differences—pigmentation of appendages and number of ascospores per ascus—between the S and K types on Syringa. Based on these morphological observations, the S and K types on Syringa were identified as E. syringae and E. syringae-japonicae, respectively. The recent abundant production of chasmothecia by lilac powdery mildew in Europe was caused by E. syringae-japonicae introduced from East Asia. DNA sequence analyses of the rDNA ITS region and the 28S rDNA, tub2, CYP51, and Chs1 genes did not support an interspecific hybrid origin for E. syringae-japonicae. Haplotype analysis suggested that E. syringae originated in North America and independently migrated to East Asia and Europe/South America.     

Xylanase of the micromycete <Emphasis Type="Italic">Rhizopus</Emphasis> var. <Emphasis Type="Italic">microsporus</Emphasis> 595: Preparation,structural and functional characteristics,and application

Procedures for the production of endo-1,4-β-xylanase have been developed. An active producer—Rhizopus var. microsporus BKMF-595—has been chosen, and the conditions of surface and submerged cultivation, as well as the composition of the culture medium for this strain, have been optimized to ensure maximum yield of the target enzyme. Activity of xylomicrosporin Px equaled 123 U/g, while the activity of xylomicrosporin Gx equaled 25 U/cm³. Homogeneous enzyme preparations, purified 59.44-fold and 72.6-fold, have been obtained. The dependence of endo-1,4-β-xylanase catalytic activity on temperature and pH of the reaction medium has been studied. The enzyme has been shown to be most stable in the pH range 5.0–6.0 and to be thermostable. Amino acid composition and subunit structure of the enzyme were determined; the molecular masses of the subunits equaled 50 and 56 kDa. Carboxyl groups of glutamic and aspartic acid residues of the active center were experimentally shown to play an important role in catalysis. The potential of this enzyme for beer production has been demonstrated.     

Effect of organic and inorganic toxic compounds on luminescence of luminous fungi

The possibility of the development of the solid phase bioluminescent biotest using aerial mycelium of luminous fungi was investigated. Effect of organic and inorganic toxic compounds (TC) at concentrations from 10⁻⁶ to 1 mg/ml on luminescence of aerial mycelia of four species of luminous fungi—Armillaria borealis (Culture Collection of the Institute of Forest, Siberian Branch, Russian Academy of Sciences), A. mellea, A. gallica, and Lampteromyces japonicus (Fungi Collection of the Botanical Institute, Russian Academy of Sciences)—has been studied. Culture of A. mellea was shown to be most sensitive to solutions of the model TC. It was demonstrated that the sensitivity of the luminous fungi is comparable with the sensitivity of the bacteria that are used for environmental monitoring. Use of the aerial mycelium of luminous fungi on the solid support as a test object is a promising approach in biotesting for the development of continuous biosensors for air monitoring.     

<Emphasis Type="Italic">Hox</Emphasis> cluster duplication in the basal teleost <Emphasis Type="Italic">Hiodon alosoides</Emphasis> (Osteoglossomorpha)

Large-scale—even genome-wide—duplications have repeatedly been invoked as an explanation for major radiations. Teleosts, the most species-rich vertebrate clade, underwent a “fish-specific genome duplication” (FSGD) that is shared by most ray-finned fish lineages. We investigate here the Hox complement of the goldeye (Hiodon alosoides), a representative of Osteoglossomorpha, the most basal teleostean clade. An extensive PCR survey reveals that goldeye has at least eight Hox clusters, indicating a duplicated genome compared to basal actinopterygians. The possession of duplicated Hox clusters is uncoupled to species richness. The Hox system of the goldeye is substantially different from that of other teleost lineages, having retained several duplicates of Hox genes for which crown teleosts have lost at least one copy. A detailed analysis of the PCR fragments as well as full length sequences of two HoxA13 paralogs, and HoxA10 and HoxC4 genes places the duplication event close in time to the divergence of Osteoglossomorpha and crown teleosts. The data are consistent with—but do not conclusively prove—that Osteoglossomorpha shares the FSGD. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

A latex lectin from <Emphasis Type="Italic">Euphorbia trigona</Emphasis> is a potent inhibitor of fungal growth

In this study we identified and characterized a major latex lectin — designated as EtLLH — with antimicrobial activity from the succulent African milk tree Euphorbia trigona. The lectin is highly concentrated in the latex of E. trigona and appears to be composed of at least two subunits with a molecular mass of 32 kDa. EtLLH shares significant similarities to known plant lectins — ricin from Ricinus communis and agglutinin from Viscum album coloratum — which specifically bind D-galactose and N-acetyl-D-glucosamine, the major building blocks of many fungal cell walls. Antimicrobial activity assays revealed an impact of EtLLH on three phytopathogenic filamentous ascomycetes. The germination of the conidiospores and the hyphal growth of Aspergillus niger and Fusarium graminearum were severely inhibited by EtLLH already at concentrations below 0.1 mg cm⁻³, while the effect on germination of the melanized conidiospores of Botrytis cinerea was less significant.     

The olfactory pathway mediates sheltering behavior of Caribbean spiny lobsters, <Emphasis Type="Italic">Panulirus </Emphasis><Emphasis Type="Italic">argus</Emphasis>, to conspecific urine signals

The “noses” of diverse taxa are organized into different subsystems whose functions are often not well understood. The “nose” of decapod crustaceans is organized into two parallel pathways that originate in different populations of antennular sensilla and project to specific neuropils in the brain—the aesthetasc/olfactory lobe pathway and the non-aesthetasc/lateral antennular neuropil pathway. In this study, we investigated the role of these pathways in mediating shelter selection of Caribbean spiny lobsters, Panulirus argus, in response to conspecific urine signals. We compared the behavior of ablated animals and intact controls. Our results show that control and non-aesthetasc ablated lobsters have a significant overall preference for shelters emanating urine over control shelters. Thus the non-aesthetasc pathway does not play a critical role in shelter selection. In contrast, spiny lobsters with aesthetascs ablated did not show a preference for either shelter, suggesting that the aesthetasc/olfactory pathway is important for processing social odors. Our results show a difference in the function of these dual chemosensory pathways in responding to social cues, with the aesthetasc/olfactory lobe pathway playing a major role. We discuss our results in the context of why the noses of many animals contain multiple parallel chemosensory systems.     

Direct evidence of <Emphasis Type="Italic">O</Emphasis>-GlcNAcylation in the apicomplexan <Emphasis Type="Italic">Toxoplasma gondii</Emphasis>: a biochemical and bioinformatic study

Toxoplasma gondii and Plasmodium falciparum are apicomplexan parasites responsible for serious diseases in humans. Many studies have focused on the post-translational modifications (PTMs) found in the two protists including phosphorylation, acetylation or SUMOylation but only a few of these are concerned with the nuclear and cytosolic-specific glycosylation O-GlcNAcylation. O-GlcNAcylation is a highly dynamic PTM—regulated by the ON and OFF enzymes: O-GlcNAc transferase and O-GlcNAcase—that can compete with phosphorylation but its function remains unclear. In this work, we directly prove the O-GlcNAcylation in T. gondii using antibodies specifically directed against the modification and we strongly suggest its occurrence in P. falciparum. We found that the inducible 70 kDa-Heat Shock Protein is O-GlcNAcylated, or associated with an O-GlcNAc-partner, in T. gondii. Using anti-OGT antibodies we were able to detect the expression of the glycosyltransferase in T. gondii cultured both in human foreskin fibroblast and in Vero cells and report its putative sequence. For the first time the presence of O-GlcNAcylation is unequivocally shown in T. gondii and suspected in P. falciparum. Since the O-GlcNAcylation is implicated in many biological fundamental processes this study opens a new research track in the knowledge of apicomplexans’ life cycle and pathogenic potential.     

Comparative analysis of respiratory activity in the wild type strain of <Emphasis Type="Italic">Neurospora crassa</Emphasis> and its photoreceptor complex mutants

Cell respiratory activity of protoplasts obtained from the wild type of Neurospora crassa and photoreceptor complex WCC—white collar 1 (wc-1) and white collar 2 (wc-2)—mutants of Neurospora crassa strains was investigated. Respiration inhibition by KCN in the presence of 25 mM succinate was similar in all strains and did not exceed 83–85% against control. The significant induction of KCN-resistant respiratory pathway occurred under 1% glucose oxidation in wc-1 and wc-2 mutants if compared with the wild type strains. The inhibitors of the main (cytochrome) pathway of electron transfer in mitochondria—1 mM KCN and antimycin A (4 μg/ml)—blocked the respiration rate of the protoplasts from N. crassa wild type by 75%, while the cell respiration of wc-1 and wc-2 strains was suppressed by approximately 50%. The specific inhibitor of alternative oxidase—10 mM salicylhydroxamic acid (SHAM)—in combination with the blockers of mitochondrial electron transfer chain caused the total suppression of respiratory activity of protoplasts in all studied strains. It is supposed that an increase of KCN-resistance in WCC mutants under glucose oxidation is connected with alternative oxidase activation as the result of failure in reception and signal transduction of active oxygen species.     

Overexpression and Inactivation of <Emphasis Type="Italic">UGT73B2</Emphasis> Modulate Tolerance to Oxidative Stress in <Emphasis Type="Italic">Arabidopsis</Emphasis>

Glycosyltransferases (GTs) play an important role in modulating solubility, stability, bioavailability, and bioactivity of secondary metabolites, such as flavonoids. In Arabidopsis thaliana, at least 120 family 1 uridine diphosphate (UDP)-glycosyltransferases (UGTs) have been predicted. However, little is known about their substrates or their physiological roles in planta. To define the role of UGT73B2 in planta, we first characterized its expression pattern using transgenic Arabidopsis plants carrying the cis-elements of UGT73B2 fused to the GUS reporter. During vegetative phase, its expression was high in embryonic and postembryonic roots, where it may play a physiological role in the glycosylation of flavonoids. Loss of function of UGT73B2 alone or in conjunction with its closest homologs, UGT73B1 and UGT73B3, confers greater tolerance to oxidative stress, whereas overexpression of UGT73B2 increases sensitivity to oxidative stress. In addition, growth phenotypes of mutant and transgenic seedlings correlate well with ROS levels in planta. Our results suggest that the glycosylation of flavonoids by UGT73B2—and/or its closest homologs—modulate the response of plants to oxidative stress.     

A Multi-Forest Comparison of Dietary Preferences and Seed Dispersal by <Emphasis Type="BoldItalic">Ateles</Emphasis> spp

Investigations of coevolutionary relationships between plants and the animals that disperse their seeds suggest that disperser-plant interactions are likely shaped by diffuse, rather than species-to-species, coevolution. We studied the role of dietary plasticity in shaping the potential for diffuse coevolution by comparing dietary fruit preferences and seed dispersal by 3 species of spider monkeys (Ateles spp.) in 4 moist forests in Colombia, Ecuador, Panama, and Surinam. In all forests, spider monkeys were highly frugivorous and preyed upon seeds of few species. We estimated dietary use of fruiting taxa based on absolute consumption and preference, which accounts for resource availability. Of the 59 genera that comprised the 20 most frequently consumed genera summed in each forest, only 3—Brosimum (Moraceae), Cecropia (Cecropiaceae) and Virola (Myristicaceae)—ranked within the top 20 at every forest. Most genera were within the 20 most frequently consumed at only 1 or 2 forests. Based on preferences, only 4 genera ranked in the 20 most-preferred in all 4 forests: Brosimum, Cecropia, Ficus (Moracae), and Virola. Patterns in fruit consumption and preference at the familial level were similar in that only 2 families—Myristicaceae and Moraceae—were in the 10 most-consumed or most-preferred in all 4 forests. Interforest variation in plant specific composition and abundances and supra-annual fruiting phenologies, combined with dietary flexibility of Ateles spp., may partly explain these patterns. Our results suggest that variation in plant community structure strongly influences dietary preferences, and hence, seed dispersal by spider monkeys. Thus, diffuse coevolution in spider monkey-plant relationships may be limited to few taxa at the generic and familial levels.     

Chitinases of <Emphasis Type="Italic">Coffea arabica</Emphasis> genotypes resistant to orange rust <Emphasis Type="Italic">Hemileia vastatrix</Emphasis>

Two Coffea arabica — Hemileia vastatrix incompatible interactions (I₁: coffee cv. Caturra — rust race VI and I₂: coffee cv S4 Agaro — rust race II) and a compatible interaction (coffee cv. Caturra — rust race II) were compared in relation to the infection process and chitinase activity. In the two incompatible interactions the fungus ceased growth in the early infection stages, while in the compatible interaction no fungus growth inhibition was observed. A high constitutive level of chitinase activity was detected in the intercellular fluid of healthy leaves. Upon infection, chitinase isoforms were more abundant in incompatible interactions than in the compatible interaction. Immunodetection showed that class I chitinases are particularly relevant in the incompatible interactions and might participate in the defence response of the coffee plants.     

Allopolyploid speciation of <Emphasis Type="Italic">Calypogeia sphagnicola</Emphasis> (Jungermanniopsida,Calypogeiaceae) based on isozyme and DNA markers

Calypogeia sphagnicola is one of nine species of the genus Calypogeia known in Europe. Occurrence of the species is closely connected with peat bogs. Nowadays, two forms of this species are distinguished—C. sphagnicola f. sphagnicola and C. sphagnicola f. paludosa. The results of the present study, based on two classes of markers—isozymes and sequences of chloroplast genom (trnH-psbA, rpoC1)—unanimously support the genetic differentiation within the taxon and show that the present-day forms represent genetically distinct species. Phylogenetic analysis resolved two lineages that correspond with the present-day forms with high bootstrap support, which differ in ploidy level: C. sphagnicola f. sphagnicola is haploid, whereas C. sphagnicola f. paludosa is a diploid form. Allopolyploid origin of the diploid form was revealed by the isozyme pattern. Nei’s genetic distance between the two present-day forms of C. sphagnicola was 0.472. The forms in Poland have an allopatric pattern of geographic distribution: C. sphagnicola f. sphagnicola occurs exclusively in the lowlands of the northern part of the country on raised peat bogs, whereas C. sphagnicola f. paludosa is found only in the mountains of southern Poland, mainly in the subalpine zone, where it grows on Sphagnum-Polytrichum hummocks on the upper part of north-facing slopes. Plants regarded in this study as C. sphagnicola f. sphagnicola morphologically correspond to the syntype specimen of C. sphagnicola.     

Social Aspects of Fur-rubbing in <Emphasis Type="Italic">Cebus capucinus</Emphasis> and <Emphasis Type="Italic">C. apella</Emphasis>

Capuchins rub particular plant materials into their pelage, a behavior for which most authors have proposed a medicinal function (Baker in American Journal of Primatology 38:263–270, 1996, Baker, M. (1998). Fur Rubbing as Evidence for Medicinal Plant Use by Capuchin Monkeys (Cebus capucinus): Ecological, Social, and Cognitive Aspects of the Behavior. Dissertation thesis. University of California Riverside; DeJoseph et al. in Journal of the American Academy of Dermatology 46:924–925, 2002). Individuals fur-rub solitarily or in groups, but researchers have not conducted studies to understand the differences. We investigated the link between the form of fur-rubbing and other social variables in 2 capuchin species. We supplied 2 captive groups —white-faced capuchins and tufted capuchins— with citrus fruit and onions and explored the behavioral processes and social aspects underlying the activity. We documented the occurrence, number of participants, and effect of recruitment behaviors in fur-rubbing subgroups. We investigated the role of kinship, affiliation, and dominance relationships in accounting for fur-rubbing groups. There is a significant difference in the form of fur-rubbing between white-faced and tufted capuchins. White-faced capuchins fur-rubbed mainly in subgroups and performed a particular behavior to recruit prospective participants, whereas tufted capuchins fur-rubbed mainly alone, and showed no particular motivation to be joined by other group members. White-faced capuchins could fur-rub together frequently, whatever their degree of kinship, affiliation, or dominance interval. In tufted capuchins, fur-rubbing appeared to be significantly affected by kinship and dominance.     

Vision as a third sensory modality to elicit attack behavior in a nocturnal spider

Cupiennius salei (Ctenidae) has been extensively studied for many years and is probably the only spider that presently can be considered a model organism for neuro-ethology. The night-active spiders have been shown to predominantly rely on their excellent mechano-sensory systems for courtship and prey capture, whereas vision was assumed to play a minor role, if any, in these behavioral contexts. Using slowly moving discs presented on a computer screen it could be shown for the first time that visual stimuli alone can elicit attack behavior (abrupt approaching reactions) in these spiders as well. These observations suggest that visual information could be used by the spiders to elicit and guide predatory behavior. Attack behavior in Cupiennius salei can thus be triggered independently by three sensory modalities—substrate vibrations, airflow stimuli, and visual cues—and offers an interesting model system to study the interactions of multimodal sensory channels in complex behavior.     

Aeration strategy: a need for very high ethanol performance in<Emphasis Type="Italic"> Saccharomyces cerevisiae</Emphasis> fed-batch process

In order to identify an optimal aeration strategy for intensifying bio-fuel ethanol production in fermentation processes where growth and production have to be managed simultaneously, we quantified the effect of aeration conditions—oxygen limited vs non limited culture (micro-aerobic vs aerobic culture)—on the dynamic behaviour of Saccharomyces cerevisiae cultivated in very high ethanol performance fed-batch cultures. Fermentation parameters and kinetics were established within a range of ethanol concentrations (up to 147 g l^–1), which very few studies have addressed. Higher ethanol titres (147 vs 131 g l^–1 in 45 h) and average productivity (3.3 vs 2.6 g l^–1 h^–1) were obtained in cultures without oxygen limitation. Compared to micro-aerobic culture, full aeration led to a 23% increase in the viable cell mass as a result of the concomitant increase in growth rate and yield, with lower ethanol inhibition. The second beneficial effect of aeration was better management of by-product production, with production of glycerol, the main by-product, being strongly reduced from 12 to 4 g l^–1. We demonstrate that aeration strategy is as much a determining factor as vitamin feeding (Alfenore et al. 2002) in very high ethanol performance (147 g l^–1 in 45 h) in order to achieve a highly competitive dynamic process.     

Modulation of biocidal activity of <Emphasis Type="Italic">Calothrix</Emphasis> sp. and <Emphasis Type="Italic">Anabaena</Emphasis> sp. by environmental factors

An investigation was undertaken to evaluate a set of cyanobacterial strains in terms of production of biocidal compounds exhibiting allelochemical and fungicidal properties. Two cyanobacterial strains — Anabaena sp. and Calothrix sp. were selected for further investigation, on the basis of their larger inhibition zones on the lawn of Synechocystis and Synechococcus sp. and two phytopathogenic fungi — Rhizoctonia bataticola and Pythium debaryanum. The diameter of the inhibition zone was largest when extracellular filtrates of the two cultures incubated at high light intensity (90–100 μmol photons m⁻² s⁻¹) and temperature (40 ± 2 °C) or grown in medium containing two-folds higher P (1.4 mg/L, as compared to 0.7 mg/L in BG 11 medium) were taken. A pH of 8 was the most optimal for both strains, in terms of growth and biocidal activity. Partial purification of ethyl acetate extract using TLC, followed by GLC revealed a single peak. This study highlights the importance of environmental factors in aggravating or reducing the toxic effects of these harmful cyanobacteria and their potential as a biocontrol agent.     

The Social Impacts of Nanotechnology: an Ethical and Political Analysis

This paper attempts some predictions about the social consequences of nanotechnology and the ethical issues they raise. I set out four features of nanotechnology that are likely to be important in determining its impact and argue that nanotechnology will have significant social impacts in—at least—the areas of health and medicine, the balance of power between citizens and governments, and the balance of power between citizens and corporations. More importantly, responding to the challenge of nanotechnology will require confronting “philosophical” questions about the sort of society we wish to create and the role that technology might play in creating it. This in turn will require developing institutions and processes that allow the public to wield real power in relation to technological trajectories. My ultimate contention is that the immediate task established by the likely social impacts of nanotechnology is not so much to develop an ethics of nanotechnology as to facilitate an ethical conversation about nanotechnology.

Comparison of <Emphasis Type="Italic">Claviceps purpurea</Emphasis> populations originated from experimental plots or fields of rye

Background  

The phytopathogenic ascomycete Claviceps purpurea causes the ergot — serious disease of rye and grasses. Its sclerotia containing toxic ergot alkaloids decrease a quality of cereal grain. The fungus infects young, unfertilized ovaries of the hosts. Due to the very short time in which infection can occur, growth rate of mycelium can play some role in the infection process. Resistance genes to C. purpurea have not been found so far.