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Fungal Interactions (fungal + interaction)
Selected AbstractsMonitoring Host Nuclear Migration and Degradation with Green Fluorescent Protein during Compatible and Incompatible Interactions of Nicotiana tabacum with Colletotrichum SpeciesJOURNAL OF PHYTOPATHOLOGY, Issue 8-9 2004X. C. Shan Abstract Recent evidence has emerged suggesting that nuclei sense and migrate towards infection sites in plants, and a novel approach to examine the dynamics of nuclei is described utilizing transgenic plants expressing a version of green fluorescent protein (GFP) that specifically labels plant nuclei. Nicotiana tabacum with GFP-labelled nuclei were inoculated with GFP-labelled strains of the hemibiotrophic fungi, Colletotrichum destructivum and C. graminicola. The nucleus in an epidermal host cell migrated to just underneath the appressorium of the compatible fungus, C. destructivum, but then migrated away from the developing fungus once it had penetrated and started to grow biotrophically. As the necrotrophic phase developed, the nuclei appeared to shrink and eventually their green fluorescence was no longer visible. The interaction of C. graminicola with N. tabacum was considered to show non-host incompatibility. The host nuclei in the epidermal cells also migrated underneath the appressoria. Once fungal penetration had failed, the nuclei then migrated back towards locations typically observed in epidermal cells of uninoculated plants. The use of both plant structures and a fungus that are labelled with a readily detectable fluorescent marker provides significant advantages as it permits direct observation of changes in living host and pathogen cells during a plant,fungal interaction. [source] Genetic processes in arbuscular mycorrhizal fungiFEMS MICROBIOLOGY LETTERS, Issue 2 2005Teresa E. Pawlowska Abstract Arbuscular mycorrhizal (AM) fungi (Glomeromycota) colonize roots of the majority of land plants and facilitate their mineral nutrient uptake. Consequently, AM fungi play an important role in terrestrial ecosystems and are becoming a component of sustainable land management practices. The absence of sexual reproductive structures in modern Glomeromycota combined with their long evolutionary history suggest that these fungi may represent an ancient asexual lineage of great potential interest to evolutionary biology. However, many aspects of basic AM fungal biology, including genome structure, within-individual genetic variation, and reproductive mode are poorly understood. These knowledge gaps hinder research on the mechanisms of AM fungal interactions with individual plants and plant communities, and utilization of AM fungi in agricultural practices. I present here the current state of research on the reproduction in AM fungi and indicate what new findings can be expected in the future. [source] Fungal endophytes in a 400-million-yr-old land plant: infection pathways, spatial distribution, and host responsesNEW PHYTOLOGIST, Issue 3 2007Michael Krings Summary ,,The Early Devonian Rhynie chert has been critical in documenting early land plant,fungal interactions. However, complex associations involving several fungi that enter into qualitatively different relationships with a single host plant and even interact with one another have not yet been detailed. ,,Here, we studied petrographic thin sections of the Rhynie chert plant Nothia aphylla. ,,Three fungal endophytes (co)occur in prostrate axes of this plant: narrow hyphae producing clusters of small spores; large spherical spores/zoosporangia; and wide aseptate hyphae that form intercellular vesicles in the cortex. Host responses on attack include bulging of infected rhizoids, formation of encasement layers around intracellular hyphae, and separation of infected from uninfected tissues by secondarily thickened cell walls. ,,A complex simultaneous interaction of N. aphylla with three endophytic fungi was discovered. The host responses indicate that some of the mechanisms causing host responses in extant plants were in place 400 million yr ago. Anatomical and life history features of N. aphylla suggest that this plant may have been particularly susceptible to colonization by fungi. [source] Frozen in time: a new method using cryo-scanning electron microscopy to visualize root,fungal interactionsNEW PHYTOLOGIST, Issue 2 2006Steve Refshauge Summary ,,A new method of sample preparation for cryo-scanning electron microscopy was used to visualize internal infection of wheat (Triticum aestivum) roots by the pathogenic fungus Rhizoctonia solani AG-8. The new method retained fungal hyphae and root cells in situ in disintegrating root tissues, thus avoiding the distortions that can be introduced by conventional preparation by chemical fixation, dehydration and embedding. ,,Infected roots frozen in liquid nitrogen were cryo-planed and etched (sublimed) at ,80°C for a critical length of time (up to 9 min) in the microscope column to reveal plant and fungal structures in three dimensions. ,,Root and fungal structures were well preserved irrespective of infection severity. Root and hyphal cell walls were clearly seen and hyphal architecture within and between root cells was preserved. ,,This rapid method permits three-dimensional in situ visualization of fungal invasion within roots and has broad application for examination of diseases caused by other necrotrophic fungi. [source] Establishment of an in vitro sciarid fly larvae assay to study plant resistanceANNALS OF APPLIED BIOLOGY, Issue 2 2009M. Chabannes Abstract Mechanisms underlying natural plant resistance to herbivorous invertebrates are still poorly understood in comparison with bacterial or fungal interactions. One reason is the difficulty in reliably and reproducibly assessing the effects under controlled conditions. This article describes a newly developed in vitro biological assay system that enables the interactions between sciarid larvae and plants, whose roots they feed on, to be studied under highly controlled conditions. The bioassay eliminates the problems created by the often variable environmental factors by providing an aseptic arena where experimental plants can be germinated and grown on agar within a Petri dish. Sciarid fly eggs are then collected, sterilised and added to the Petri dish. The system allows the eggs to hatch and the larvae to feed on the plant roots. A range of developmental parameters can then be recorded over time which can then be correlated with the experimental plant type. This assay system also allows a simultaneous comparison or ,choice chamber' between two (or more) different genotypes. The assay should greatly help to facilitate the identification of new components involved in insect resistance mediated pathway via the characterisation of mutant plants. [source] | ||||||||||