Learn More
Certain isolates of the plant-pathogenic fungus Nectria haematococca mating population VI (MPVI) contain dispensable chromosomes that are unstable during sexual reproduction. Several of these chromosomes carry genes for phytoalexin detoxification and thus contribute to the pathogenic potential of this organism. A repeated DNA sequence, Nht1, was cloned from(More)
InNectria haematococca theMAK1 gene product converts a chick-pea (Cicer arietinum) phytoalexin, maackiain, into a less toxic compound. The presence ofMAK1 in this fungal pathogen is also correlated with high virulence on chick-pea. Previous genetic analysis suggested thatMAK1 is located on a meiotically unstable, dispensable chromosome. The unstable nature(More)
A procedure for inducing and detecting the loss of conditionally dispensable (CD) chromosomes in filamentous fungi during vegetative growth was developed using Nectria haematococca mating population VI as a model. CD chromosomes in two different isolates of N. haematococca were tagged via integrative transformation with a gene conferring resistance to(More)
Fungal xylanases from Trichoderma spp. are potent elicitors of defense responses in various plants. To determine whether enzymatic activity is necessary for elicitor activity, we used site-directed mutagenesis to reduce the catalytic activity of xylanase II from Trichoderma reesei. For this, the glutamic acid residue at position 210, which is part of the(More)
Total membranes prepared from roots of soybean (Glycine max L.) seedlings have previously been shown to contain proteinaceous binding site(s) for a hepta-beta-glucoside elicitor of phytoalexin accumulation. The hepta-beta-glucoside elicitor-binding proteins have now been shown to co-migrate with a plasma membrane marker enzyme (vanadate-sensitive(More)
Certain isolates of the plant pathogenic fungus Nectria haematococca mating population (MP) VI contain a 1.6-Mb conditionally dispensable (CD) chromosome carrying the phytoalexin detoxification genes MAK1 and PDA6-1. This chromosome is structurally unstable during sexual reproduction. As a first step in our analysis of the mechanisms underlying this(More)
Pandora neoaphidis is one of the most important fungal pathogens of aphids and has a great potential for use in biocontrol. Little is known on how this fungus persists in an area and in particular on its overwintering strategies. It is hypothesized that natural areas play an important role for survival and that soil may serve as a source of inoculum for new(More)
Residual activity of polymerase chain reaction DNA polymerases in restriction analyses strongly affected genetic profiling based on terminal restriction fragment length polymorphisms. Artificial fragment sizes produced as a result of 5'-overhang restriction site fill-in and addition of a terminal A may bias genetic profiling and genotyping of microbial(More)
Soil fungal community structures are often highly heterogeneous even among samples taken from small field plots. Sample pooling is widely used in order to overcome this heterogeneity, however, no objective criteria have yet been defined on how to determine the number of samples to be pooled for representatively profiling a field plot. In the present study(More)
GerminatingCochliobolus sativus spores were induced to form appressoria on a variety of artificial surfaces, including replicas of the barley leaf surface. Evidence was obtained for the involvement of chemical and topographic signals during induction of appressorium formation inC. sativus. Germ tube thigmotropism was also observed in vitro. Ultrastructure(More)