Studies on trehalase in Saccharum spp. leaf and storage tissues

Trehalase properties and behavior were examined in commercialsugarcane varieties (predominandy S. officinarum), pure S. spontaneumclones, and pure S. robustum clones propagated in sand culture.The standard commercial variety, P. R. 980, contained trehalasein all tissues except the leaf sheath, widi greatest activitylocalized in expanding internodes and spindle leaves. OptimumpH was 6.0 and the Michaelis constant was 6.3 ? 10^–4 Mfor trehalose. Foliar experiments based on leaf rank, variableillumination, and diurnal sugar and enzyme changes gave no evidenceof trehalase involvement in sugar transport processes. Activitylevels ranged from 4- to 10-fold higher in S. spontaneum clonesthan in commercial varieties. Present evidence suggests a trehalaserole in sugar utilization rather than sugar storage which favoredthe evolutionary survival of primitive Saccharum forms. ¹Present address: Biophysics Program, Washington State University,Pullman, Washington 99163, U.S.A. (Received July 4, 1972; )