For Blighted Waves of Grain: Fusarium graminearum in the Postgenomics Era

Extract

Fungi display astounding diversity in their pathogenicity. We categorize them as biotrophs or necrotrophs and as obligate or facultative pathogens, but these categories do not reflect their polymorphic nature. Our approach to controlling disease would be better served by improving our understanding of the complete life cycle of the fungal pathogen, from infection and colonization to overwintering, using all of the tools at our disposal. A handful of fungal plant pathogens are now being studied at this level, including Fusarium graminearum (sexual stage, Gibberella zeae), the causal agent of head blight of wheat (Triticum aestivum), oat (Avena sativa), and barley (Hordeum vulgare) and ear and stalk rot of maize (Zea mays). Although F. graminearum is arguably one of the best studied fungal plant pathogens, the genetic bases of its life cycle and pathogenicity are poorly defined. This article focuses on the contributions that genomics and postgenomic studies are making to our understanding of the entire life cycle of this important pathogen. The genome of this fungal pathogen cannot be viewed in isolation, just as the fungus does not exist in isolation. Genomics can be used to elucidate F. graminearum's interaction with its hosts, leading to a clearer picture of its ecological niche.