The Bursting of the Hyphal Tips of Dendryphiella salina and the Relevance of the Phenomenon to Repression of Glucose Transport

SUMMARY: Observations on Dendryphiella salina have confirmed that bursting of hyphal apices is brought about by an excessive water potential gradient across the hyphal membrane. Low concentrations of the non-metabolizable sugars 3-O-methyl-glucose and l-sorbose are much more effective than metabolizable sugars in producing bursting. However, at high concentrations they have a protective effect by reducing the water potential gradient. These observations allow a reinterpretation of sugar transport kinetic data which suggested that the glucose transport system in filamentous fungi can exist in two states dependent on the repressive effect of glucose.