Labelling of the hyphal walls of basidiospore germlings of with radioactive glucose resulted in immediate labelling of the glucans but labelling of chitin was delayed for about 20 min. Radioactive glucose could thus be used as a specific label for wall glucans in a 10 min labelling pulse. Special attention was given to the alkali-insoluble glucans containing (1→3)-β and (1→6)-β linkages and occurring in close association with chitin. Using [3-H]glucose and treating the labelled glucans with periodate, a distinction could be made between glucose residues incorporated in (1→3) and in (1→6) linkages and the spatial distribution of these synthetic activities could be followed by microautoradiography. The results indicated that in growing hyphae the alkali-insoluble glucan synthesized at the apex was very rich in (1→3) linkages and that synthesis of (1→6) linkages increased subapically from about 10°% at the apex to about 60% just outside the extension zone. Inhibition of hyphal growth with cycloheximide or by low glucose concentrations inhibited glucan synthesis at the apex but not in subapical parts. At the same time a shift towards synthesis of (1→6) linkages was observed at the apex.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error