Besides stimulating the production and release of hydrolases, GA3
can also retard enzyme synthesis. Consistent with the observation that GA3
induces the degradation of aleurone-layer cell walls is the observation that
it inhibits the synthesis of pentosan (xylose and arabinose) components of
the wall, in part owing to the reduced activity of a membrane-bound arabi-
nosyl transferase and perhaps also of xylosyl transferase. Changes in such
membrane-bound enzymes could reflect a shift in the role of membranes
from the production of cell wall components to the synthesis and packaging
of hydrolases.