New (and used) approaches to the study of fungal pathogenicity.

The fungi are the most economically important plant pathogens and continue to be the focus of extensive research with a wide variety of methodologies. Enhancements in microscopy techniques have increased our ability to visualize the intimate interaction of fungi and their host plants. Improving methods allow pharmacological inhibition and genetic dissection of the determinants of fungal pathogenicity in a gene-by-gene approach. Identification and analysis of genes differentially transcribed in ways pertinent to pathogenicity continues to be a frequent research approach. Genome-wide analysis is gaining favor in biological research and fungal plant pathogens are no exception. Several industrial research groups are exploring fungal plant pathogenesis based on genomic sequence data and genome-wide mutagenesis. In March 2001 the first publicly available complete genome of a filamentous fungus (Neurospora crassa) was released. N. crassa is of course a saprophyte and there is no complete sequence available for a plant pathogenic fungus in public databases. However, freely accessible entire genome sequences for both plant pathogenic fungi and their hosts are on the horizon. Sequence availability promises to revolutionize the rate at which data relevant to disease processes will be accrued. In this review we describe approaches currently applied to the study of plant pathogenic fungi and explore developments of potential future benefit with existing technologies not yet applied to this group of important organisms.