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Necrotrophic Fungi (necrotrophic + fungus)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Host-derived media used as a predictor for low abundant, in planta metabolite production from necrotrophic fungi

JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006
D.P. Overy
Abstract Aims:,Penicillium ser. Corymbifera strains were assayed on a variety of media and from infected Allium cepa tissues to evaluate the stimulation and in planta prediction of low abundance metabolites. Methods and Results:, Stimulated production of corymbiferones and the corymbiferan lactones were observed for Penicillium albocoremium, Penicillium allii, Penicillium hirsutum, Penicillium hordei and Penicillium venetum strains cultured on tissue media. Target metabolites were sporadically detected from strains cultured on common laboratory media (CYA, MEA and YES). Up to a 376 times increase in corymbiferone and corymbiferan lactone production was observed when culture extracts from CYA and A. cepa agar were compared by high pressure liquid chromatography with ultraviolet and mass spectrometry (LC-UV-MS). The novel metabolite corymbiferone B was purified and structure elucidated from a P. allii/A. cepa tissue medium extract. In planta expression of low abundance, target metabolites were confirmed from infected A. cepa tissue extracts by LC-UV-MS. Conclusions:, Secondary metabolite production was directly dependent and influenced by media conditions, resulting in the stimulated production of low abundance metabolites on host-derived media. Significance and Impact of the Study:, The use of macerated host tissue media can be applied in vitro to predict in planta expression of low abundance metabolites and aid in metabolite origin annotation during in planta metabolomic investigations at the host/pathogen interface. [source]

Botrytis cinerea: the cause of grey mould disease

MOLECULAR PLANT PATHOLOGY, Issue 5 2007
BRIAN WILLIAMSON
SUMMARY Introduction:,Botrytis cinerea (teleomorph: Botryotinia fuckeliana) is an airborne plant pathogen with a necrotrophic lifestyle attacking over 200 crop hosts worldwide. Although there are fungicides for its control, many classes of fungicides have failed due to its genetic plasticity. It has become an important model for molecular study of necrotrophic fungi. Taxonomy:, Kingdom: Fungi, phylum: Ascomycota, subphylum: Pezizomycotina, class: Leotiomycetes, order: Helotiales, family: Sclerotiniaceae, genus: Botryotinia. Host range and symptoms: Over 200 mainly dicotyledonous plant species, including important protein, oil, fibre and horticultural crops, are affected in temperate and subtropical regions. It can cause soft rotting of all aerial plant parts, and rotting of vegetables, fruits and flowers post-harvest to produce prolific grey conidiophores and (macro)conidia typical of the disease. Pathogenicity:,B. cinerea produces a range of cell-wall-degrading enzymes, toxins and other low-molecular-weight compounds such as oxalic acid. New evidence suggests that the pathogen triggers the host to induce programmed cell death as an attack strategy. Resistance:, There are few examples of robust genetic host resistance, but recent work has identified quantitative trait loci in tomato that offer new approaches for stable polygenic resistance in future. Useful websites:,http://www.phi-base.org/query.php, http://www.broad.mit.edu/annotation/genome/botrytis_cinerea/Home.html, http://urgi.versailles.inra.fr/projects/Botrytis/, http://cogeme.ex.ac.uk [source]

Frozen in time: a new method using cryo-scanning electron microscopy to visualize root,fungal interactions

NEW PHYTOLOGIST, Issue 2 2006
Steve 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]

RLM3, a TIR domain encoding gene involved in broad-range immunity of Arabidopsis to necrotrophic fungal pathogens

THE PLANT JOURNAL, Issue 2 2008
Jens Staal
Summary Here, we describe the rapid cloning of a plant gene, Leptosphaeria maculans 3 (RLM3Col), which encodes a putative Toll interleukin-1 receptor-nucleotide binding (TIR-NB) class protein, which is involved in defence against the fungal pathogen L. maculans and against three other necrotrophic fungi. We have, through microarray-based case control bulk segregant comparisons of transcriptomes in pools of Col-0 × An-1 progeny, identified the absence of a locus that causes susceptibility in An-1. The significance of this locus on chromosome 4 for L. maculans resistance was supported by PCR-based mapping, and denoted resistance to RLM3Col. Differential susceptible phenotypes in four independent T-DNA insertion lines support the hypothesis that At4g16990 is required for RLM3Col function. The mutants in RLM3Col also exhibited an enhanced susceptibility to Botrytis cinerea, Alternaria brassicicola and Alternaria brassicae. Complementations of An-1 and T-DNA mutants using overexpression of a short transcript lacking the NB-ARC domain, or a genomic clone, restored resistance to all necrotrophic fungi. The elevated expression of RLM3Col on B. cinerea -susceptible mutants further suggested convergence in signalling and gene regulation between defence against B. cinerea and L. maculans. In the case of L. maculans, RLM3Col is required for efficient callose deposition downstream of RLM1Col. [source]