Recycling glass fibre-reinforced plastics in the automotive sector

The automotive sector is facing the challenge to become more resource-efficient in the manufacture of cars and theircomponents. One approach is to increase the share of recycled materials. This paper presents the results of a case study for the automotive sector of the EU-funded Zerowin project. A safety-relevant component of the brakingsystem was selected for manufacture using a mechanically recycled composite plastic material (polyethyleneterephthalate reinforced with short glass fibres). The case study demonstrated the interdependencies between material and component specification, component design, material properties and the production process: using recycled glass-fibre-reinforced plastics for a safety-relevant component is not just an issue of input substitution, it is an interplay of technological (product development, production process modification, recycling process), organisational (security of supply, network infrastructure) and economic (material cost savings versus adjustment costs, planning horizons) factors resulting from the input substitution of primary material and changes of material properties. An industrial network was established and the case study’s findings were transferred to serial mass production. Industrial networks are seen as an appropriate tool for securing the supply and quality of recyclates from traceable sources

G proteins in Ustilago maydis: transmission of multiple signals?

In the phytopathogenic fungus Ustilago maydis, cell fusion is governed by a pheromone signalling system. The pheromone receptors belong to the seven transmembrane class that are coupled to heterotrimeric G proteins. We have isolated four genes (gpa1 to gpa4) encoding alpha subunits of G proteins. Gpa1, Gpa2 and Gpa3 have homologues in other fungal species, while Gpa4 is novel. Null mutants in individual genes were viable and only disruption of gpa3 caused a discernible phenotype. gpa3 mutant strains were unable to respond to pheromone and thus were mating-deficient. A constitutively active allele of gpa3 (gpa3(Q206L)) was generated by site-directed mutagenesis. Haploid strains harbouring gpa3(Q206L) were able to mate without pheromone stimulation, indicating that Gpa3 plays an active role in transmission of the pheromone signal. Surprisingly, Gpa3 is also required for pathogenic development, although pheromone signalling is not essential for this process

Calmodulin interacts with MLO protein to regulate defence against mildew in barley

In plants, defence against specific isolates of a pathogen can be triggered by the presence of a corresponding race-specific resistance gene, whereas resistance of a more broad-spectrum nature can result from recessive, presumably loss-of-regulatory-function, mutations. An example of the latter are mlo mutations in barley, which have been successful in agriculture for the control of powdery mildew fungus (Blumeria graminis f. sp. hordei; Bgh). MLO protein resides in the plasma membrane, has seven transmembrane domains, and is the prototype of a sequence-diversified family unique to plants, reminiscent of the seven-transmembrane receptors in fungi and animals. In animals, these are known as G-protein- coupled receptors and exist in three main families, lacking sequence similarity, that are thought to be an example of molecular convergence. MLO seems to function independently of heterotrimeric G proteins. We have identified a domain in MLO that mediates a Ca2+-dependent interaction with calmodulin in vitro. Loss of calmodulin binding halves the ability of MLO to negatively regulate defence against powdery mildew in vivo. We propose a sensor role for MLO in the modulation of defence reactions.close17017

The Mak2 MAP kinase signal transduction pathway is required for pathogenicity in Stagonospora nodorum

A gene encoding a mitogen-activated protein kinase (MAPK) putatively orthologous to Pmk1 from Magnaporthe grisea was cloned and characterised from the wheat glume blotch pathogen Stagonospora nodorum. Protein sequence alignments showed the cloned gene, Mak2, is closely related to homologues from other dothideomycete fungi. Expression studies revealed Mak2 is up-regulated during in vitro growth upon nitrogen starvation but is not sensitive to carbon starvation or osmotic stress. Transcript analysis in planta showed Mak2 to be expressed throughout infection and up-regulated during the sporulation phase of the infection cycle. Fungal strains harbouring a disrupted Mak2 gene were created by homologous gene recombination. The mutant strains had a severely altered phenotype in vitro with reduced growth rate and failure to sporulate. Further phenotypic analysis revealed that the mutants had near-normal levels of secreted protease activity, were not hypersensitive to osmotic stress and appeared to have melanin synthesis intact. The mak2 strains were essentially non-pathogenic to wheat leaves. No penetration structures formed and although entry was observed through stomates, the infection rarely continued. The results within this study are discussed within the context of the differences in downstream regulation of the Mak2 MAPK pathway and the cAMP signal transduction pathway in S. nodorum; and differences are compared to mak2 mutant strains in other pathogenic fungi