Bemerkenswerte Vitalitätsschwächung und Holzzersetzung an Rot-Buchen (Fagus sylvatica) durch den weitgehend unbekannten Schlauchpilz Hypoxylon cohaerens

In the years 2005 and 2006 several declining and recently died beech trees were investigated in a large city park in Dresden. The ascomycete Hypoxylon cohaerens, who is exclusively characterized as a saprophytic fungus by literature, was identified as a conspicuous cause of the disease. The symptoms of the infection, the morphologically and physiologically characteristics of the fungus in situ and in vitro as well as the factors of predisposition are presented in the article. Since H. cohaerens attains pathological importance and can be mistaken for some other ascomycetes, the distinguishing marks to related species are described. The changed importance of the fungus is evaluated for practice.     

Substituted alpha-(phenylhydrazono)phenylacetonitrile derivatives. Part 2: Synthesis and biological activity of pro-pesticides

Pro-pesticides of alpha-(2,6-dichloro-4-trifluoromethylphenylhydrazono)-4-nitrophenylacetonitrile have been prepared and tested against mite and insect pests. Variations in potency and spectrum were observed depending on the choice of cleavable pro-moiety. Cleavage of the pro-moiety was demonstrated in one case by measuring the rate of increase in the uncoupling activity using a mitochondrial preparation. Irradiation experiments have demonstrated a rapid isomerisation of the planar Z isomer to the E isomer, which is reversible.     

松属线粒体基因序列变异研究

本研究利用ＰＣＲ和ＰＣＲ产物直接序列分析技术,获得了分属于松属（Ｐｉｎｕｓ）两个亚属Ｐｉｎｕｓ和Ｓｔｒｏｂｕｓ１２个松树种ｃｏｘＩ、ａｔｐ６和ｏｒｆ２５三个线粒体基因ＤＮＡ片段的序列。发现ｃｏｘＩ基因的ＤＮＡ序列在属内没有任何变异,但ａｔｐ６和ｏｒｆ２５在两个亚属间和亚属内出现了较多的碱基置换。这说明尽管裸子植物线粒体基因有较多的ＲＮＡ编辑（ＲＮＡｅｄｉｔｉｎｇ）存在,可促进ＤＮＡ序列的变异,但促进程度因不同基因而异。依据ａｔｐ６和ｏｒｆ２５所做的系统进化树不仅与分类结果一致,而且进一步表明了亚属内种间的亲缘关系。尽管线粒体基因序列变异比叶绿体和核ＤＮＡ变异小,线粒体基因编码序列变异仍适于研究裸子植物亚属甚至组间的系统进化关系。     

Electrospinning and mechanical properties of polymeric fibers using a novel gap-spinning collector

Tissue engineering is an interdisciplinary field which combines the basic principles of life sciences and engineering. One promising idea is the combination of scaffolds and living cells in order to produce new functional tissue. The scaffolds play the role of a microenvironment that guides the cells towards tissue formation and regeneration. One of the most frequently used techniques to produce scaffolds is electrospinning. Tissue engineered constructs have to exhibit physiological and mechanical properties comparable to the native tissue they are intended to replace. To create polymeric fibers with controlled orientation, a cylindrical collector that rotates at a certain speed could be used, creating fibers that run longitudinally. The process of gap-spinning enables the production of specifically aligned fibers. Aim of this study was to develop a novel setup capable of producing multilayered structures with controlled fiber angle. The structural, morphological and mechanical characteristics of the fibers were accessed using scanning electron microscopy and uniaxial tensile tests. Longer pre-stretching led to thinner (in the sub-micron scale), more brittle and less elastic fibers. In a nutshell, the results indicated that fiber mats of desired orientation, fiber diameter and mechanical properties could be produced by controlled gap-spinning with a translational collector.     

Weitere Beobachtungen an Kulturen vonPorphyridium cruentum (Ag.) Naeg. mariner Herkunft

Zusammenfassung In Kulturversuchen wurden die Nährstoffansprüche vonPorphyridium cruentum bei besonderer Berücksichtigung der zum guten Gedeihen für erforderlich gehaltenen Meerwasser- oder Meersalzzugabe und die Eignung verschiedener stickstoffhaltiger Verbindungen untersucht. Aus den Ergebnissen lassen sich Hinweise zur Ökologie der Alge am natürlichen Standort ableiten.

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Summary By means of culture experiments investigations were made on the nutrient requirements ofPorphyridium cruentum with special regard to its presumed demand of sea-water or sea-salt supply. Futhermore nitrogenous substances were tested relative to their value as a nitrogen source. The results of these investigations gave a hint at the ecological conditions of this alga in its natural environment.

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Phorphyridium cruentum . , . .

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Zugleich Veröffentlichung aus der Forschungsstelle für Limnologie, Jena, der Deutschen Akademie der Wissenschaften zu Berlin.     

Beiträge zur Kenntnis der Phycomyceten IV.Pleotrachelus wildemani Petersen neu für Deutschland

Zusammenfassung Die OlpidiaceePleotrachelus wildemani Petersen (1910), bisher nur aus Dänemark und Großbritannien bekannt, wurde in Moosprotonemen erstmalig für Deutschland gefunden, mit dem Wirt kultiviert und durch Infektionsversuche auf ihr Wirtsspektrum geprüft. Drei Laubmoosarten zeigten sich anfällig, auf Lebermoose gelang eine Übertragung bisher nicht. An den Kulturen konnten der vegetative Entwicklungszyklus verfolgt und die Variationsmöglichkeiten der Zoosporangienform studiert werden.

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Summary The occurrence ofPleotrachelus wildemani Petersen (1910) (Olpidiaceae) hitherto found only in Denmark and Great Britain is now reported even for Germany, in the neighbourhood of Gatersleben, parasitic in moss-protonema. The phycomycete was cultivated together with a host plant in order to trace his life history on living material with special regard to the variability of Zoosporangia. Inoculation experiments demonstrated that the fungus is capable to infect the protonema of several species of Musci. Infection of Liverworts however could not yet be detected.

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. Olpidiaceae,Pleotrachelus wildemani Petersen (1910), , . . ; . .

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Zugleich Veröffentlichung aus der Forschungsstelle für Limnologie Jena der Deutschen Akademie der Wissenschaften zu Berlin.     

The co-operative interaction of puroindolines in wheat grain texture may involve the hydrophobic domain

The puroindoline genes are causatively associated with wheat grain hardness, a commercially significant property. The proteins puroindoline (PIN) A and B are both required in their wild-type (WT) to impart soft grain texture, and absence of/mutations in either/both PIN(s) results in hard wheat. However, there is no biochemical clarity yet that explains this interdependence. This work critically analyses the roles of the tryptophan-rich domain (TRD), the little-known hydrophobic domain (HD), and certain other residues, in the physical associations of PINs. Site-directed mutagenesis-PCR was used to delete the TRD or HD and introduce an Arg39Gly substitution in PINA. The PINB-D1c mutant (Leu60Pro) was also investigated. The yeast two-hybrid system was used to assess the protein–protein interactions (PPI) of proteins. The TRD deletion or Arg39Gly substitution in PINA did not adversely affect its PPI, while deletion of HD resulted in a significant reduction. No effect on PPI was observed for Leu60Pro PINB. The results of this expression system strongly suggest that the HD is essential (but not sufficient) in higher-order associations of PINs. We propose a two-event model that explains the co-operative action of the PINs and why mutations outside the TRD may alter grain texture.