Tox-boxes, fungal secondary metabolites, and plant disease

摘要

Many plant pathogens secrete toxins that disable their host (1). Some of these have general phytotoxic properties and are active toward a broad range of plant species. Others are host-selective, affecting only certain plant varieties or genotypes. These host-selective toxins (HSTs) can act as agents of virulence of pathogens to toxin- sensitive hosts, so determining host range or specificity (1,2). Nearly all HSTs that have been described are low molecular weight secondary metabolites produced by fungi. The genes required for the synthesis of these molecules are often tightly clustered in the fungal genome and are coordinately regu- lated (3).