Durch Seitenwurzelbildung induzierte und spontane Mitosen in den Dauergeweben der Wurzel

Ohne ZusammenfassungDie wesentlichen Untersuchungsergebnisse wurden im Rahmen einer Doktorarbeit am Botanischen Institut der Universität Wien gewonnen. Für Anregung und förderliche Kritik danken wir Herrn Prof. Dr. L.Geitler bestens.     

Effects of high metal concentrations on antioxidative system in Phragmites australis grown in mine and flotation tailings ponds

Plant and Soil - Phragmites australis grows as a pioneer plant species in several mine and flotation tailings ponds distinguished by extremely high concentrations of metals. The main goals of this...     

Iminoglycinuria in a child in Czechoslovakia

Summary The child with iminoglycinuria is in our observation. Hyperprolinuria was seen at 5 months by screening program. The child was repeatedly examined in the hospital and was seen last time at 16 months. IQ was 67, in the urine were excessive amounts of glycine, proline a hydroxyproline. In the blood aminoacids were in normal levels. In the child was noticed the same increase of proline in the blood as in the control child of the same age following loading test with L-proline, indicating normal intestinal absoption. Both parents and father's sister's 2-year-old mentally retarded child exhibit excessive glycinuria. The father, his sister, father's father, and grandfather are partialy, congenitaly deaf.     

Absence of co-phylogeny indicates repeated diatom capture in dinophytes hosting a tertiary endosymbiont

Tertiary endosymbiosis is proven through dinophytes, some of which (i.e. Kryptoperidiniaceae) have engulfed diatom algae containing a secondary plastid. Chloroplasts are usually inherited together permanently with the host cell, leading to co-phylogeny. We compiled a diatom sequence data matrix of two nuclear and two chloroplast loci. Almost all endosymbionts of Kryptoperidiniaceae found their closest relatives in free-living diatoms and not in other harboured algae, rejecting co-phylogeny and indicating that resident diatoms were taken up by dinophytes multiple times independently. Almost intact ultrastructure and insignificant genome reduction are supportive for young, if not recent events of diatom capture. With their selective specificity on the one hand and extraordinary degree of endosymbiotic flexibility on the other hand, dinophytes hosting diatoms share more traits with lichens or facultatively phototrophic ciliates than with green algae and land plants. Time estimates indicate the dinophyte lineages as consistently older than the hosted diatom lineages, thus also favouring a repeated uptake of endosymbionts. The complex ecological role of dinophytes employing a variety of organismic interactions may explain their high potential and plasticity in acquiring a great diversity of plastids.     

Type IV pili are widespread among non-pathogenic Gram-positive gut bacteria with diverse carbohydrate utilization patterns

Type IV pili (T4P) are bacterial surface-exposed appendages that have been extensively studied in Gram-negative pathogenic bacteria. Despite recent sequencing efforts, little is known regarding these structures in non-pathogenic anaerobic Gram-positive species, particularly commensals of the mammalian gut. Early studies revealed that T4P in two ruminal Gram-positive species are associated with growth on cellulose, suggesting possible associations of T4P with substrate utilization patterns. In the present study, genome sequences of 118 taxonomically diverse, mainly Gram-positive, bacterial strains isolated from anaerobic (gastrointestinal) environments, have been analysed. The genes likely to be associated with T4P biogenesis were analysed and grouped according to T4P genetic organization. In parallel, consortia of Carbohydrate Active enZYmes (CAZymes) were also analysed and used to predict carbohydrate utilization abilities of selected strains. The predictive power of this approach was additionally confirmed by experimental assessment of substrate-related growth patterns of selected strains. Our analysis revealed that T4P systems with diverse genetic organization are widespread among Gram-positive anaerobic non-pathogenic bacteria isolated from different environments, belonging to two phylogenetically distantly related phyla: Firmicutes and Actinobacteria.