Evidence for stimulation of glucose-6-phosphate dehydrogenase synthesis during initiation of periodic fruit body growth in Agaricus bisporus

Abstract

Agaricus bisporus fruit bodies were harvested over several cycles of periodic fruiting (flushes) and assayed for glucose 6-phosphate dehydrogenase (G6PD) activity and for G6PD protein by enzyme-linked immunosorbent assay. The peaks of G6PD activity observed during flush emergence were accompanied by increases in enzyme protein. There was also an increase in G6PD molecular specific activity at flush emergence. Polyacrylamide gel electrophoresis and immunoassay suggested that this was due to the synthesis of a new form of G6PD at flush emergence, which was not antigenic to antibody raised against the constitutive enzyme. G6PD activity in the mycelium was low at all stages of the flushing cycle, as was G6PD protein. However, there was some evidence for the presence of the “new” form of G6PD in the mycelium at the time of flush emergence.