STARCH METABOLISM IN GERMINATING SOYBEAN COTYLEDONS IS SENSITIVE TO CLINOROTATION AND CENTRIFUGATION

Soybean (Glycine max [L.] Merr. cv. McCall) seedlings germinated and g rew for 6d under the altered gravity conditions of horizontal clinorot ation and centrifugation. Both of these conditions resulted in decreas ed growth relative to the control (vertically rotated) plants. Starch concentration in the cotyledons was lower in the clinorotated plants a nd was higher in the centrifuged plants compared to the controls. The opposite relationship was noted for total Lipid concentration. Of the six starch metabolic enzyme activities measured, only ADP glucose pyro phosphorylase was affected by the gravity treatments; being lower in t he cotyledons of the horizontally rotated plants and higher in the cot yledons of the centrifuged plants relative to the control values.