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Im Folgenden werden für das östliche Ruhrgebiet bemerkenswerte Funde aufgeführt. Das Gebiet umfasst die Städte Gelsenkirchen, Essen, Herne, Bochum, Dortmund, Hagen und Hamm sowie die Kreise Recklinghausen, Unna und den Ennepe-Ruhr-Kreis. Die Funde sind zu einem Teil unter www.botanik-bochum.de/html/funde2013.htm mit Fotos versehen. Zur besseren Auswertung wurden hinter den Fundorten die MTB-Angaben (Topographische Karte 1:25.000) angegeben und ggf. eine Bewertung des Fundes für den hiesigen Raum und der floristische Status hinzugefügt. Funde aus dem östlichen Ruhrgebiet, die von nordrhein-westfälischer Bedeutung sind, sind in der Liste "Beiträge zur Flora Nordrhein-Wesfalens"
(Bochumer Botanischer Verein 2014, Beitrag in diesem Jahrbuch) aufgeführt.
Das Jahrbuch für 2013 enthält sechs bereits vorab online publizierte Veröffentlichungen des Bochumer Botanischen Vereins, Berichte über zahlreiche Exkursionen, eine Zusammenstellung "bemerkenswerter Pflanzenvorkommen aus dem östlichen Ruhrgebiet im Jahr 2013", "Beiträge zur Flora Nordrhein-Westfalens aus dem Jahr 2013" sowie zahlreiche Pflanzenporträts und ein Programm des 47. Westfälischen Floristentags.
This paper deals with the control exerted by the mitochondrial translocator FLX1, which catalyzes the movement of the redox cofactor FAD across the mitochondrial membrane, on the efficiency of ATP production, ROS homeostasis, and lifespan of S. cerevisiae. The deletion of the FLX1 gene resulted in respiration-deficient and small-colony phenotype accompanied by a significant ATP shortage and ROS unbalance in glycerol-grown cells. Moreover, the flx1Δ strain showed H2O2 hypersensitivity and decreased lifespan. The impaired biochemical phenotype found in the flx1Δ strain might be justified by an altered expression of the flavoprotein subunit of succinate dehydrogenase, a key enzyme in bioenergetics and cell regulation. A search for possible cis-acting consensus motifs in the regulatory region upstream SDH1-ORF revealed a dozen of upstream motifs that might respond to induced metabolic changes by altering the expression of Flx1p. Among these motifs, two are present in the regulatory region of genes encoding proteins involved in flavin homeostasis. This is the first evidence that the mitochondrial flavin cofactor status is involved in controlling the lifespan of yeasts, maybe by changing the cellular succinate level. This is not the only case in which the homeostasis of redox cofactors underlies complex phenotypical behaviours, as lifespan in yeasts.
Here we present a formal description of Biremis panamae Barka, Witkowski et Weisenborn sp. nov., which was isolated from the marine littoral environment of the Pacific Ocean coast of Panama. The description is based on morphology (light and electron microscopy) and the rbcL, psbC and SSU sequences of one clone of this species. The new species is included in Biremis due to its morphological features; i.e. two marginal rows of foramina, chambered striae, and girdle composed of numerous punctate copulae. The new species also possesses a striated valve face which is not seen in most known representatives of marine littoral Biremis species. In this study we also present the relationship of Biremis to other taxa using morphology, DNA sequence data and observations of auxosporulation. Our results based on these three sources point to an evolutionary relationship between Biremis, Neidium and Scoliopleura. The unusual silicified incunabular caps present in them are known otherwise only in Muelleria, which is probably related to the Neidiaceae and Scoliotropidaceae. We also discuss the relationship between Biremis and the recently described Labellicula and Olifantiella.
Escherichia coli α-hemolysin (HlyA) is a pore-forming protein of 110 kDa belonging to the family of RTX toxins. A hydrophobic region between the amino acid residues 238 and 410 in the N-terminal half of HlyA has previously been suggested to form hydrophobic and/or amphipathic α-helices and has been shown to be important for hemolytic activity and pore formation in biological and artificial membranes. The structure of the HlyA transmembrane channel is, however, largely unknown. For further investigation of the channel structure, we deleted in HlyA different stretches of amino acids that could form amphipathic β-strands according to secondary structure predictions (residues 71–110, 158–167, 180–203, and 264–286). These deletions resulted in HlyA mutants with strongly reduced hemolytic activity. Lipid bilayer measurements demonstrated that HlyAΔ71–110 and HlyAΔ264–286 formed channels with much smaller single-channel conductance than wildtype HlyA, whereas their channel-forming activity was virtually as high as that of the wildtype toxin. HlyAΔ158–167 and HlyAΔ180–203 were unable to form defined channels in lipid bilayers. Calculations based on the single-channel data indicated that the channels generated by HlyAΔ71–110 and HlyAΔ264–286 had a smaller size (diameter about 1.4 to 1.8 nm) than wildtype HlyA channels (diameter about 2.0 to 2.6 nm), suggesting that in these mutants part of the channel-forming domain was removed. Osmotic protection experiments with erythrocytes confirmed that HlyA, HlyAΔ71–110, and HlyAΔ264–286 form defined transmembrane pores and suggested channel diameters that largely agreed with those estimated from the single-channel data. Taken together, these results suggest that the channel-forming domain of HlyA might contain β-strands, possibly in addition to α-helical structures.
Coevolution of viruses and their hosts represents a dynamic molecular battle between the immune system and viral factors that mediate immune evasion. After the abandonment of smallpox vaccination, cowpox virus infections are an emerging zoonotic health threat, especially for immunocompromised patients. Here we delineate the mechanistic basis of how cowpox viral CPXV012 interferes with MHC class I antigen processing. This type II membrane protein inhibits the coreTAP complex at the step after peptide binding and peptide-induced conformational change, in blocking ATP binding and hydrolysis. Distinct from other immune evasion mechanisms, TAP inhibition is mediated by a short ER-lumenal fragment of CPXV012, which results from a frameshift in the cowpox virus genome. Tethered to the ER membrane, this fragment mimics a high ER-lumenal peptide concentration, thus provoking a trans-inhibition of antigen translocation as supply for MHC I loading. These findings illuminate the evolution of viral immune modulators and the basis of a fine-balanced regulation of antigen processing.
As part of a wider study of floodplain vegetation along the River Murray, we carried out a field survey in 1987–1988 involving collection of floristic and vegetation condition data from 335 sample plots (each 400 m2 in area), between Hume Dam and Lake Alexandrina (including the Edward-Wakool anabranch system). The floodplain vegetation is dominated by just two tree species, River Red Gum (Eucalyptus camaldulensis) and Black Box (Eucalyptus largiflorens), but the composition of the understorey shows much greater variation, both along the river and across the floodplain. A total of 499 plant species, subspecies and varieties were recorded from the survey plots, of which 316 (63%) were native and 183 (37%) were exotic. From analysis of the floristic data we identified 37 vegetation communities, not including the vegetation of permanent wetlands and cleared areas; 21 communities were distinguished in the River Red Gum zone, 12 communities in the Black Box zone, and 4 communities on rises within the floodplain. The main floristic division among the River Red Gum communities was between Riverine Plain/ Headwaters Zone communities of the upper Murray, and Mallee Zone communities of the lower Murray. Among the Black Box communities, the main floristic division was between inner floodplain communities and outer floodplain communities, with a further division between South Australian communities and New South Wales/Victorian communities. Major factors influencing the floristic patterns included flooding frequency/duration and soil salinity.
Eucalypt health declined steadily downstream and was poorest in the lower reaches of the river below the Darling Junction, where 60% of the trees were healthy, 18% unhealthy (at least 40% of the canopy dead) and 22% dead. By comparison, at the upper end of the river, above Tocumwal, 84% of the trees were healthy, 14% unhealthy and only 2% dead. Overall, the condition of Black Box trees (44% unhealthy or dead) was worse than the condition of River Red Gum trees (29% unhealthy or dead). Eucaypt regeneration was also poorest below the Darling Junction, with regenerants present in 77% of plots upstream of the Darling but only 35% of plots downstream. The findings of poor tree health and sparse regeneration below the Darling coincide with the most heavily regulated part of the Murray, where the reduction in flooding due to upstream storages and water extraction, mainly for irrigation, has been greatest. Black Box regeneration was much sparser overall than River Red Gum regeneration (regenerants present in 69% of River Red Gum plots but only 29% of Black Box plots). The poor condition of the Black Box trees, coupled with their poor regeneration, suggests that the long-term future of this species along the Murray, particularly below the Darling Junction, is tenuous, even though it is a dominant component of the vegetation.
The integrity of floodplain vegetation along the Murray has been severely compromised by weed invasion. Weeds were common throughout the survey area, but were most prevalent in the climatically wetter sections of the river, at both the downstream and upstream ends (below Mannum and above Tocumwal). The median number of exotic species per plot equalled or exceeded the number of native species in these sections of the river, whereas native species outnumbered exotic species in the other river sections. Communities of the River Red Gum zone and the rises were generally weedier than those of the Black Box zone. Exotic species strongly influenced the community classification. They were the dominant overstorey species in two communities (Salix species – willows) and outnumbered native species in the understorey of another eight communities. At the lower end of the river, below Mannum, the River Red Gums that originally fringed the river had been mostly replaced by dense thickets of the exotic Weeping Willow, Salix babylonica.
Other factors that have impacted on the floodplain vegetation at the plant community level have been river regulation and soil salinisation. Stabilization of water levels in the lower Murray by construction of a series of weirs and barrages has favoured the spread of some communities at the expense of others. The favoured communities, which are characterised by stands of Common Reed, Phragmites australis, along the water’s edge, appear to be artefacts of river regulation. Salinisation has resulted in death of eucalypts and replacement of eucalypt communities by shrub communities dominated by samphires, Tecticornia species. The samphire community characteristic of the most saline sites is one of the most species-poor communities on the Murray floodplain.
Logging along the Murray in New South Wales and Victoria has resulted in extensive replacement of old growth River Red Gum forests and woodlands by more even-aged stands of straight young trees. Following the recent conversion of many areas of State Forest along the Murray in both New South Wales and Victoria to National Park or Regional Park, and thus the cessation of logging in these areas, they should now revert gradually to mature forest and woodland.
This study is the first to describe broad scale floristic patterns in the floodplain vegetation of the Murray covering most of the length of the river. It also provides data on the vegetation condition in the 1980s, and provides a benchmark of conditions before the prolonged Millenium Drought in south-eastern Australia from 1997 to 2010. More recent surveys of vegetation condition have reported a severe decline in tree health during the drought. The results from our 1987–88 survey are important because they show that the deteriorating condition of the vegetation was already evident in the 1980s and although exacerbated by the subsequent drought, it is not just a consequence of that drought. The results are consistent with the conclusion that the primary cause of the decline has been river regulation and water extraction for irrigation. The rate of deterioration has increased rapidly since the 1980s because of the drought. There has been some improvement since the breaking of the drought, but the poor condition of the River Murray floodplain vegetation, an Australian icon, remains a major conservation and management issue. The impacts of climate change – higher temperatures and reduced rainfall – have compounded the problem and will continue to do so at an increasing rate. The results of the study support listing of the floodplain vegetation of the lower reaches of the river as a critically endangered ecological community.
The riparian rainforest on the streamside levees of the coastal floodplain of the Clarence River on the North Coast of New South Wales was cleared during the 1860s by small landholders seeking fertile land. Only three small remnants remain. Using a combination of historical species lists, corner trees from surveyors’ portion plans, habitat information and the NSW Scientific Committee’s (1999) determination for lowland rainforest on floodplain a conceptual model of the original distribution of rainforest suballiances on the levees of the Clarence River coastal floodplain is proposed.
Population size, and flowering and fruiting developmental stages in the Critically Endangered species Corunastylis sp. ‘Charmhaven’ (Family Orchidaceae, formerly included within genus Genoplesium), were investigated in the Warnervale-Charmhaven area over a three year period. Population size in 2012 was 11 plants, in 2013, 14 plants and in 2014 increased to 26 plants, with new plants appearing near the original plants. Proactive management, including mowing and erecting wire protective cages around groups of orchids was partly responsible for this increase in numbers because it prevented browsing by rabbits but only ten plants carried fruits to maturity in the 2014 season to produce seed. Despite an increase in numbers over a couple of years, a population of 26 individuals is very small and warrants maintaining the current conservation listing of Critically Endangered. The population began to flower between 15th and 29th February in 2012 and from 3rd to 14th March in 2013. However in 2014 flowering began on 11th February and extended to 19th March but it took until 17th June to reach the seed dispersal stage. 2014 involved two phases of flowering; whether climatic factors were responsible for this event is not known.