Endogenous Auxin Profile in the Christmas Rose (Helleborus niger L.) Flower and Fruit: Free and Amide Conjugated IAA

The reproductive development of the Christmas rose (Helleborus niger L.) is characterized by an uncommon feature in the world of flowering plants: after fertilization the white perianth becomes green and photosynthetically active and persists during fruit development. In the flowers in which fertilization was prevented by emasculation (unfertilized) or entire reproductive organs were removed (depistillated), the elongation of the peduncle was reduced by 20?C30%, and vascular development, particularly lignin deposition in sclerenchyma, was arrested. Chlorophyll accumulation in sepals and their photosynthetic efficacy were up to 80% lower in comparison to fertilized flowers. Endogenous auxins were investigated in floral and fruit tissues and their potential roles in these processes are discussed. Analytical data of free indole-3-acetic acid, indole-3-ethanol (IEt), and seven amino acid conjugates were afforded by LC-MS/MS in floral tissues of fertilized as well as unfertilized and depistillated flowers. Among amino acid conjugates, novel ones with Val, Gly, and Phe were identified and quantified in the anthers, and in the fruit during development. Reproductive organs before fertilization followed by developing fruit at post-anthesis were the main source of auxin. Tissues of unfertilized and depistillated flowers accumulated significantly lower levels of auxin. Upon depistillation, auxin content in the peduncle and sepal was decreased to 4 and 45%, respectively, in comparison to fruit-bearing flowers. This study suggests that auxin arising in developing fruit may participate, in part, in the coordination of the Christmas rose peduncle elongation and its vascular development.     

Diversity of Fusarium Species Isolated from Weeds and Plant Debris in Croatia

Weeds are alternative hosts of plant pathogens and when colonized may not exhibit disease symptoms. In 2008 and 2009, samples of weeds and plant debris were collected from 12 locations in eastern Croatia, and 300 Fusarium isolates colonizing them were identified. Strains were grouped and identified based on morphology and amplified fragment length polymorphism (AFLP) patterns. Portions of the β‐tubulin and translocation elongation factor 1‐α genes were sequenced from representative strains of each group to confirm the identifications. Fourteen Fusarium species were identified with F. graminearum (20%), F. verticillioides (18%), F. oxysporum (16%), F. subglutinans (13%) and F. proliferatum (11%) all present as more than 10% of the population. Fusarium acuminatum, F. avenaceum, F. concolor, F. crookwellense (F. cerealis), F. equiseti, F. semitectum, F. solani, F. sporotrichioides and F. venenatum, were all present at frequencies < 8%. Our results indicate that economically important Fusarium spp. may be isolated from numerous alternative hosts during the off season and that weeds and plant debris can serve as a reservoir of genetically diverse inoculum.     

Serum immunoglobulins IgG, IgA and IgM in patients with oral lichen ruber

The aim of this study was to determine level of serum IgA, IgG and IgM in patients with OLR as indicators of humoral immunity which might reflect cell-mediated immunity. This study was conducted on 30 patients (age 60.17 +/- 11.75) with clinically and histopathologically confirmed diagnosis of OLR and 30 healthy controls (age 56.16 +/- 11.82) Determination of serum IgA, IgG and IgM was performed by use of standard laser nephelometry in both patients and controls. Statistical analysis was done using Mann-Whitney U test and the level of significance was determined as p values lower than 0.05. Serum IgA and IgM in patients with OLR were significantly increased in comparison to the control group, while serum IgG levels were higher in patients with OLR but they did not reach significance. We might conclude that elevated levels of serum IgA and IgM show that humoral immunity is implicated in the pathogenesis of OLR.     

Structural characterization of extracellular lipase from Streptomyces rimosus: assignment of disulfide bridge pattern by mass spectrometry

The cloning, sequencing and high-level expression of the gene encoding extracellular lipase from Streptomyces rimosus R6-554W have been recently described, and the primary structure of this gene product was deduced using a bioinformatic approach. In this study, capillary electrophoresis-on-the-chip and mass spectrometry were used to characterize native and overexpressed extracellular lipase protein from S. rimosus . The exact molecular mass of the wild-type and the overexpressed lipase, determined by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry, were in excellent agreement (Deltam=0.11 Da and Deltam=0.26 Da, respectively) with a value of 24165.76 Da calculated from the structure deduced from the nucleotide sequence, considering the mature enzyme with all six cysteines forming disulfide bridges. The primary structure derived from the nucleotide sequence was completely verified using a combination of tryptic digestion and formic acid cleavage of the protein, followed by peptide mass fingerprinting. Selected peptides were further investigated by MALDI low-energy collision-induced dissociation hybrid tandem mass spectrometry, allowing the unambiguous determination of their predicted amino acid sequence. No post-translational modifications of mature S. rimosus lipase were detected. Comparison of the peptide mass fingerprints from the reduced and non-reduced overexpressed enzyme unequivocally revealed three intramolecular disulfide bonds with the following linkages: C27-C52, C93-C101 and C151-C198.     

Microbiological analysis of a mummy from the archeological museum in Zagreb

In this paper we report the results of the microbiological analysis of the samples taken from the mummy from the collection of the Archaeological museum in Zagreb, Croatia. Samples were taken from specific places such as oral, orbital, abdominal cavity and bandages surrounding the mummy, and analyzed in Department of Microbiology and Hospital Infections in University Hospital "Dubrava" in Zagreb and in National Reference Laboratory for systemic mycoses of Croatian National Institute of Public Health in Zagreb. The analysis indicated that all of the found organisms were non-primary pathogenic and are not harmful for healthy humans. Isolated microorganisms mainly belonged to the group of saprophytic fungi as listed: Monilia spp., Penicillium spp., Alternaria spp., Aspergillus fumigatus, Aspergillus nidulans, Rhizopus spp. and Chrysosporium spp. and to the genus of saprophytic bacteria, Bacillus spp.     

Julije Klovi?: the first colour drawing of Greater Bird of Paradise Paradisaea apoda in Europe and its model

The prayer book The Hours of the Blessed Virgin Mary, known as The Farnese Hours, was illustrated by the Croatian miniaturist, Julije Klović, between 1539 and 1546 in Rome. In this masterpiece of Renaissance miniature art, Klović drew in colour a bird of paradise. In 2001, the pictured bird was determined to be a Raggiana Bird of Paradise, Paradisaea raggiana P. L. Sclater 1873. Our later determination shows that it is actually a Greater Bird of Paradise Paradisaea apoda (Linnaeus 1758) and the first drawing of this species in colour in Europe. Klović’s model for the Greater Bird of Paradise was one of the first trade skins of birds of paradise that, from 1522, had been arriving in Europe. Revision of the early drawings of the birds of paradise species in Europe, relevant to the Klović drawing model, has also been carried out and is discussed.     

Multiple forms of metallothionein from the digestive gland of naturally occurring and cadmium-exposed mussels, Mytilus galloprovincialis

Polymorphism of metallothioneins in the digestive gland of naturally occurring (control) and experimentally Cd-exposed mussels Mytilus galloprovincialis (200 μg Cd l^–1; 14 days) was studied by applying the conventional methods of Sephadex column liquid chromatography (G-75 and DEAE A-25), and by an electrochemical method (DPASV) for determination of Cd, Zn and Cu concentrations in chromatographic fractions. In both control and Cd-exposed mussels, two distinct molecular mass components of the metallothioneins, monomeric (MT-10) and dimeric (MT-20), were resolved by Sephadex G-75 gel filtration chromatography. In control mussels, the MT-10 component was predominantly expressed as containing markedly higher constitutive levels of Zn (100×) and Cu (10×) than of Cd. Each of these two molecular mass components was further resolved into seven metal-rich peaks by anion-exchange chromatography. In Cd-exposed mussels the larger proportion of Cd was bound to the MT-20 than to the MT-10 component, suggesting that the dimeric component may be considered as a primarily inducible metallothionein. The elution positions of metal-binding maxima of Cd-exposed and control mussels on the respective DEAE chromatographic profiles were comparable. A great similarity in elution positions of Cd maxima between the composite and single-specimen samples was also observed. Our study confirms a high multiplicity of MT forms in mussels from the Mytilus genus not only under the laboratory high-level metal exposure conditions, but also at a natural seawater metal exposure level. The ecotoxicological significance of dimeric and monomeric MT forms, as well as their possible application in the biomonitoring of seawater for trace metals, has been considered. Electronic Publication     

Micromorphological differences between some European and American <Emphasis Type="Italic">Fraxinus</Emphasis> (<Emphasis Type="Italic">Oleaceae</Emphasis>) species

Micromorphological differences in leaves and pollen between two American (Fraxinus americana L., F. pennsylvanica Marshall) and two European (F. angustifolia Vahl, F. excelsior L.) ash species were studied using scanning electron microscope. The types, dimensions and distribution of characteristic trichomes were established and measured. Capitate hairs on the leaves had the same shape in all researched ash species. Acicular hairs were regularly present in two American ash species, but very rarely in the glabrous phase of F. angustifolia and F. excelsior. Only F. americana had coronulate abaxial surface of leaves. Pollen of F. angustifolia and F. excelsior had 3 (tricolpate) apertures, and F. americana and F. pennsylvanica 4 (stephanocolpate) apertures. Based on the appearance of the reticulum it’s possible to clearly distinguish all four species. F. angustifolia and F. pennsylvanica had muri with transversal ridges and seldom granules. Muri of F. excelsior and F. americana had slightly visible transversal ridges, and because of that noticeable granules.