THE INFLUENCE OF ALTERED GRAVITY ON CARBOHYDRATE-METABOLISM IN EXCISED WHEAT LEAVES

We developed a system to study the influence of altered gravity on car bohydrate metabolism in excised wheat leaves by means of clinorotation . The use of excised leaves in our clinostat studies offered a number of advantages over the use of whole plants, most important of which we re minimization of exogenous mechanical stress and a greater amount of carbohydrate accumulation during the time of treatment. We found that horizontal clinorotation of excised wheat leaves resulted in signific ant reductions in the accumulation of fructose, sucrose, starch and fr uctan relative to control, vertically clinorotated leaves. Photosynthe sis, dark respiration and the extractable activities of ADP glucose py rophosphorylase (EC 2.7.7.27), sucrose phosphate synthase (EC 2.4.4.14 ), sucrose sucrose fructosyltransferase (EC 2.4.1.99), and fructan hyd rolase (EC 3.2.1.80) were unchanged due to altered gravity treatment.