ABSTRACT
In parasitic fungi (e.g. rusts), both intercellular hyphae and haustoria within host cells are important locations for nutrient translocation at interfaces. Haustoria are organs of fungal pathogens that develop intracellular^ in root/leaf tissue. They are comparable to arbuscule in a symbiotic AM fungal interaction, especially with regard to bi-directional nutrient translocation. For example, haustoria of powdery mildews mediate nutrient transfer between the biotrophs. Hahn and Mendgen (2001) have pointed out that high H+ATPase activity at haustoria compared with spores or mycelium of the powdery mildew fungus is a clear indication of nutrient transport activity at haustorial interfaces. Induction and expression patterns of hexose and/or amino acid transporters also support the view that plant interfaces between plant cell with haustoria mediate nutrient transport (e.g. Uromyces fabae on bean). The transcripts for amino acid and/or sugar transporter proteins are easily traced in the haustoria, although intercellular hyphae may also contribute to nutrient transfer from host cell. Clearly, the haustorial interfaces with host cells are major locations of nutrient transport in plant versus pathogenic fungal interactions (e.g. rust fungus).
