The effect of electron acceptors on the phytochrome-controlled germination of Paulownia tomentosa seeds

The effect of substances with different redox potentials in the phytochrome-controlled germination of Paulmtnia tomentosa seeds was examined. Up to 25% of water-imbibed seeds germinated upon irradiation with 5 min red light The seeds irradiated with 5 min red light and incubated in substances with redox potentials equal or higher than E'₀= 360 mV [potassium nitrate, potassium hexacyanoferrate (III) or potassium hexachloroiridate (IV)] and sodium nitroprusside germinated up to 80%. The optimal concentration was between 1 and 10 mM. Other electron acceptors such as 2.6-dichlorophenol-indoplhenol, phenazine methosulfate and methylene blue failed to produce and effect. The germination-promoting effect was obtained when the substances were supplied to the incubation medium from the onset of imbibition or at the onset of irradiation. Delay of application of these chemicals until after the red light treatment diminished their effectiveness and the effect was lost after 48 h. The escape from far-red reversibility was evident in the presence of substances which stimulated germination. The results presented support the view that phytochrome-broken dormancy of Paulownia tomentosa seeds is closely connected with redox changes.     

An Efficient Alternative Route To 3,6-Disubstituted-Furo[2,3-d]Pyrimidin-2-One Analogues

Copper(I)-catalyzed 5-endo-dig cyclizations of 5-(alkyn-1-yl)uracil derivatives had given poor yields of substituted furo[2 Robins, M. J. and Barr, P. J. 1983. Nucleic acid related compounds. 39. Efficient conversion of 5-iodo to 5-alkynyl and derived 5-substituted uracil bases and nucleosides. J. Org. Chem, 48: 1854–1862. [CSA][CROSSREF][Crossref], [Web of Science ®] , [Google Scholar], 3 De Clercq, E., Descamps, J., Balzarini, J., Giziewicz, J., Barr, P. J. and Robins, M. J. 1983. Nucleic acid related compounds. 40. Synthesis and biological activities of 5-alkynyluracil nucleosides. J. Med. Chem, 26: 661–666. [PUBMED][INFOTRIEVE][CSA][CROSSREF][Crossref], [PubMed], [Web of Science ®] , [Google Scholar]]pyrimidin-2-ones unless the uracil ring was substituted at N1 with alkyl or glycosyl groups. This limited flexibility for the synthesis of analogues with varied substituents at N3 and/or C6 of the furo[2 Robins, M. J. and Barr, P. J. 1983. Nucleic acid related compounds. 39. Efficient conversion of 5-iodo to 5-alkynyl and derived 5-substituted uracil bases and nucleosides. J. Org. Chem, 48: 1854–1862. [CSA][CROSSREF][Crossref], [Web of Science ®] , [Google Scholar], 3 De Clercq, E., Descamps, J., Balzarini, J., Giziewicz, J., Barr, P. J. and Robins, M. J. 1983. Nucleic acid related compounds. 40. Synthesis and biological activities of 5-alkynyluracil nucleosides. J. Med. Chem, 26: 661–666. [PUBMED][INFOTRIEVE][CSA][CROSSREF][Crossref], [PubMed], [Web of Science ®] , [Google Scholar]]pyrimidin-2-one core has been overcome with 5-(3-hydroxyalkyn-1-yl)uracil compounds with no substituent at N1. Manipulation of the side-chain hydroxyl group gives access to additional furo[2,3-d]pyrimidin-2-one analogues.     

Chemical Diversity of the Natural Populations of Dalmatian Pyrethrum (Tanacetum cinerariifolium (Trevir.) Sch.Bip.) in Croatia

Dalmatian pyrethrum (Tanacetum cinerariifolium (Trevir. ) Sch.Bip. ) is a plant species endemic to the east Adriatic coast. The bioactive substance of Dalmatian pyrethrum is a natural insecticide, pyrethrin, a mixture of six active components (pyrethrins I and II, cinerins I and II, and jasmolins I and II). The insecticidal potential of pyrethrin was recognized decades ago, and dried and ground flowers have traditionally been used in Croatian agriculture and households. A total of 25 Dalmatian pyrethrum populations from Croatia were studied to determine the pyrethrin content and composition, and to identify distinct chemotypes. The total pyrethrin content ranged from 0.36 to 1.30% (dry flower weight; DW) and the pyrethrin I/pyrethrin II ratio ranged from 0.64 to 3.33%. The statistical analyses revealed that the correlations between the percentage of pyrethrin I and of all the other components were significant and negative. The total pyrethrin content was positively correlated with the percentage of pyrethrin I and negatively correlated with cinerin II. The multivariate analysis of the chemical variability enabled the identification of five chemotypes among 25 Dalmatian pyrethrum populations. The chemical characterization of indigenous Dalmatian pyrethrum populations may serve as a good background for future breeding and agricultural exploitation.     

Identification of quantitative trait loci for resistance to Verticillium wilt and yield parameters in hop (Humulus lupulus L.)

Verticillium wilt (VW) can cause substantial yield loss in hop particularly with the outbreaks of the lethal strain of Verticillium albo-atrum. To elucidate genetic control of VW resistance in hop, an F₁ mapping population derived from a cross of cultivar Wye Target, with the predicted genetic basis of resistance, and susceptible male breeding line BL2/1 was developed to assess wilting symptoms and to perform QTL mapping. The genetic linkage map, constructed with 203 markers of various types using a pseudo-testcross strategy, formed ten major linkage groups (LG) of the maternal and paternal maps, covering 552.98 and 441.1 cM, respectively. A significant QTL for VW resistance was detected at LOD 7 on a single chromosomal region on LG03 of both parental maps, accounting for 24.2–26.0 % of the phenotypic variance. QTL analysis for alpha-acid content and yield parameters was also performed on this map. QTLs for these traits were also detected and confirmed our previously detected QTLs in a different pedigree and environment. The work provides the basis for exploration of QTL flanking markers for possible use in marker-assisted selection.     

Impact of the Chromatin Remodeling Factor CHD1 on Gut Microbiome Composition of Drosophila melanogaster

The composition of the intestinal microbiota of Drosophila has been studied in some detail in recent years. Environmental, developmental and host-specific genetic factors influence microbiome composition in the fly. Our previous work has indicated that intestinal bacterial load can be affected by chromatin-targeted regulatory mechanisms. Here we studied a potential role of the conserved chromatin assembly and remodeling factor CHD1 in the shaping of the gut microbiome in Drosophila melanogaster. Using high-throughput sequencing of 16S rRNA gene amplicons, we found that Chd1 deletion mutant flies exhibit significantly reduced microbial diversity compared to rescued control strains. Specifically, although Acetobacteraceae dominated the microbiota of both Chd1 wild-type and mutant guts, Chd1 mutants were virtually monoassociated with this bacterial family, whereas in control flies other bacterial taxa constituted ~20% of the microbiome. We further show age-linked differences in microbial load and microbiota composition between Chd1 mutant and control flies. Finally, diet supplementation experiments with Lactobacillus plantarum revealed that, in contrast to wild-type flies, Chd1 mutant flies were unable to maintain higher L. plantarum titres over time. Collectively, these data provide evidence that loss of the chromatin remodeler CHD1 has a major impact on the gut microbiome of Drosophila melanogaster.     

Genetic diversity and morphological variability in the Balkan endemic Campanula secundiflora s.l. (Campanulaceae)

We reconstructed the relationships among populations of Campanula secundiflora s.l. and closely related and geographically close populations of C. austroadriatica and C. versicolor. Based on analyses of microsatellite DNA data, the investigated populations have high overall genetic diversity and abundant allelic variation over seven investigated loci. Bayesian model‐based clustering identified four clearly differentiated genetic groups of populations. The genetic differentiation was reflected by morphological differentiation, allowing us to propose a new taxonomic treatment of the constituents of C. secundiflora s.l. The populations distributed in south‐western Serbia and north‐eastern Montenegro were included in C. secundiflora. A new species, C ampanula montenegrina sp. nov. , distributed in the continental part of Montenegro and the northern part of Albania is described. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180 , 64–88.     

Contributo alla conoscenza dell'ecologia delle biocenosi sulle cascade travertinose nella regione Carstica Jugoslava

Riassunto Il nostro lavoro di molti anni sulle cascade travertinose dei fiumi carstici jugoslavi era diretto verso le esplorazioni delle condizioni di vita su questi specifici biotopi. A causa di questa specificità loro erano potuti popolati solo da determinati specie di piante e di animali, i queli sono adattati su queste condizioni speciali. Esse creano le associazioni, ai queli fa la base la vigorosa vegetazione di muschi e di alghe, e un po'di meno anche di altri piante. Questa vegetazione e accompagnata da numerosi rappresentanti dai diversi gruppi di animali, come queli di Turbellaria, Gastropoda, Oligochaeta, Hirudinea, Amphipoda, Insecta ed a.Dai fattori ecologici erano esplorati le condizioni di vita fisicochimiche e biologiche. In estate la temperatura dell'aqua era sempre oltre la temperatura-limite di deposizione (oltre 14° C), e durante l'inverno generalmente erano le condizioni inconvenienti per i processi di deposizione.Nella parte superficiale delle cascade abiamo constatato due specie di abitazione in relazione della luce. Forte illuminate cascade erano popolate dalle associazioni della luce, ed a causa di meno calcificata vegetazione erano molto più. ricche di animali. Meno illuminate cascade avevano più favorevoli condizioni per il sviluppo della vegetazione travertinosa, la quale era molto calcificata, the cosa non porgeva favorevoli condizioni per il sviluppo del mondo animale.Abiamo constatato the la più favorevole velocità dell'aqua per lo sviluppo dei organismi, i quali popolano i posti delle cascade travertinose, è tra 0,5 e l,5 m/sec., sebbene sui singoli abitazioni la velocita dell'aqua era fra 0,5–3,5 m/sec.A causa di una favorevole alcalità, la quale nelle aque esplorate ammonta tra 2,8 e 5,2, i processi di deposizione sono molto attivi. E costattato un graduale abassamento dell'alcalità in direzione scendente del flume, the cosa si mette in relazione colla perdita del carbonato durante il processo di deposizione.La quantità del ossigeno ammontava da 3,5–9 ccm/l. e perciò generalmente tutte queste aque si possono considerare come poliossitipiche.Per le biocenosi delle cascade travertinose e caratteristica una grande dinamica nel Toro sviluppo. Le più primitive forme delle associazioni sono composte principalmente dai idrofiti. Con un avanzato sviluppo delle formazioni travertinose appariscono nuove stazioni con nuove associazioni. Il climax presenta la vegetazione fanerogama, la quala crew stazioni ombreggiate, dove si sviluppa speciale vegetazione travertinosa dell' ombra. Questi cambiamenti di vegetazione vengono accompagnati da numerose specie di animali dei gruppi Amphipoda, Ephemerida, Trichoptera, Plecoptera, Coleoptera ed a.In fine sono dimostrate le principali caratteristiche di vita in relazione colle condizioni fisico-chimiche e biologiche.

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Summary For a number of years, our work on travertine cascades of Yugoslav Karstic rivers has been directed towards the study of living conditions in these specific biotypes. Owing to their specificity, they could have been inhabited only by certain plant and animal species which have been adapted to these specific conditions. Their communities have been created on a rich moss and seaweed vegetation basis and, to a somewhat smaller extent, also on that of other plants. This vegetation is accompanied by numerous representatives of various animal groups such as: turbellaria, gastropods, oligochaeta, hirudinoids, amphipods, insects et al.As far as ecologic factors are concerned, physical, chemical and biological living conditions have been studied. In summer, water temperature is always above the deposition boundary (above 14°C), while in winter, conditions are generally unfavourable for deposition processes.In connection with light, two habitats were observed on the surface parts of the cascades. The strongly lighted cascades were inhabited by light communities which were considerably richer in animal population, owing to poorly calcified vegetation. As to the development of travertine vegetation, poorly lighted cascades which had been amply calcified, were in a much more favourable position and thus provided unfavourable conditions for the development of animal life.The water speed most favourable for the development of organisms inhabiting travertine cascades has been found to lie between 0.5 and 1.5 meters per second, although in individual habitats water speed amounted to between 0.5 and 3.5 meters per second.Owing to favourable alkalinity, amounting, in the waters investigated, to between 2.8 and 5.2, depositing processes have been very intense. The gradual lowering of alkalinity in the downstream course of rivers, which is brought into connection with the losing of carbonates during the deposition process, has also been established.As the quantity of oxygen amounted to between 3.5–9 ccm/l, these waters can be considered to be polyoxitypical.The biocenosis on travertine cascades are characterized by their very dynamic development. The most primitive forms of communities are mainly composed of hydrophytes. The further development of travertine forms brings about new habitats with new communities. The climax is represented by phanerogamic vegetation, creating rocky habitats where special travertine shade vegetation develops. These changes in vegetation have been accompanied by numerous animal species of the afore-mentioned groups.Finaly, the main characteristics of life in terms of physical, chemical and biological conditions have been presented.

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Zusammenfassung Die mehrjärige Arbeit der Autoren auf den Kalktuffbildenden Wasserfällen der jugoslawischen Karstgewässer war den Erforschungen der Lebensbedingungen auf diesen spezifischen Biotopen gewidmet. Wegen ihrer Eigentümlichkeit konnten die Kalktuffwasserfälle nur von bestimmten Pflanzen- und Tierarten besiedelt werden, die an these besonderen Bedingungen angepasst sind. Sie bilden Gemeinschaften auf eine üppige Moos- und Algenvegetation und etwas weniger auch auf anderen Pflanzen. Diese Vegetation wird von zahlreichen Vertretern verschiedener Tiergruppen begleitet, wie Turbellaria, Gastropoda, Oligochaeta, Hirudinea, Amphipoda, Insecta u.a.Von ökologischen Faktoren wurden die physikalisch-chemischen und biologischen Bedingungen untersucht. Im Sommer war die Wassertemperatuur immer über der Grenztemperatur der Ablagerung (über 14°C), während die Ablagerungsbedingungen im Winter im allgemeinen ungünstig waren.In den oberflächenlichen Teilen der Wässer\:falle wurden, im Verhältnis zu dem Licht, zwei Arten von Standorten festgestellt. Die stark belichteten Wasserfälle sind von Lichtgerneinschaften besiedelt, die wegen der weniger kalzifizierten Vegetation viel mehr Tiere enthalten. Weniger belichtete Wasserfälle zeigen günstigere Bedingungen für eine Entwicklung der Kalktuffvegetation. Diese Vegetation wird sehr kalzifiziert und ist für der Entwicklung der Tierwelt ungünstig.Es wurde festgestellt, dass die günstige Wassergeschwindigkeit für die Entwicklung von Organismen, die die Standorte der Kalktuffwasserfälle besiedeln, zwischen 0,5 and 1,5 m-Sek ist, wiewohl die Wassergeschwindigkeit an einzelnen Standorten zwischen 0,5 and 3,5 m-Sek betrug.Wegen der günstigen Alkalität (2,8–5,2) sind die Ablagerungsvorgänge sehr aktiv. Flussabwärts wurde ein allmählicher Fall der Alkalitätwerte festgestellt, was auf den Verlust des Karbonates während der Ablagerungsvorgänge zurückgeführt wird.Die Sauerstoffmenge beträgt zwischen 3,5–9 ccm/l; im allgemeinen können wir deshalb all these Gewässer als polyoxytypisch betrachten.Für die Gemeinschaften der Kalktuffwasserfälle ist eine grosse Dynamik in ihrer Entwicklung charakteristisch. Die primitivsten Formen der Lebensgemeinschaften sind hauptsächlich aus Hydrophyten zusammengesetzt. Mit der weiteren Entwicklung der Kalktufformen erscheinen neue Standorte mit neuen Gemeinschaften. Das Klimax stellt die Vegetation der höheren Pflanzen tar, die Schattenstandorte macht, wo sich eine besondere Schattenkalktuf-vegetation entwickelt. Diese Vegetationsänderungen werden von zahlreichen Tierarten der genanten Gruppen begleitet.Zum Schluss wird die Hauptcharakteristik des Lebens in Bezug auf die physikalisch-chemischen und biologischen Bedingungen dargestellt.

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Botaniki institut Univerziteta Zagreb

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Bioloki institut Univerziteta Zagreb     

ArrayNorm: comprehensive normalization and analysis of microarray data

SUMMARY: ArrayNorm is a user-friendly, versatile and platform-independent Java application for the visualization, normalization and analysis of two-color microarray data. A variety of normalization options were implemented to remove the systematic and random errors in the data, taking into account the experimental design and the particularities of every slide. In addition, ArrayNorm provides a module for statistical identification of genes with significant changes in expression. AVAILABILITY: The package is freely available for academic and non-profit institutions from http://genome.tugraz.at