Fungal defences against animal antagonists - Lectins & more

Abstract

Unlike in the laboratory, in nature fungi are exposed to antagonists including competitors, pathogens, parasites and predators. In this issue of Molecular Ecology, an exciting paper by Bleuler-Martínez (2011) has unearthed on one of the processes used by fungi to protect themselves against animal antagonists. The authors from Markus Künzler′s group at the ETH Zürich, Switzerland present direct evidence that filamentous fungi possess an inducible resistance mechanism against predators and parasites. This is based on cytoplasmic lectins, which specifically bind to glycans of these predators and parasites, and thus provide toxicity against them. These lectins are expressed at high levels in fruiting bodies and sclerotia of these fungi (Fig. 1). While there have been previous suggestions and efforts to implicate mycotoxins such as sterigmatocystin into fungal defence mechanisms and as an evolutionary force (see Kempken & Rohlfs 2010), the data presented by Markus Künzler′s group highlight the ecological relevance of lectins in defending fungi from parasites and fungivorous animals. As such this paper provides important ecological clues and suggests that secondary metabolites are not the sole player in fungal-animal competition. It rather appears that fungi have evolved several lines of defence against antagonistic organisms. Fungi protect their fruiting bodies by the use of lectin (picture of Aleuria aurantia provided by Taylor F. Lockwood). © 2011 Blackwell Publishing Ltd.