Seeds of Sesbania virgata have galactomannan as a storage polysaccharide in the endosperm. During mobilization, the degradation products are assimilated by the cotyledons which later supply this carbon source to the embryo. Sucrose is of prime importance in this source and sink relation between the organs. In the present work, the importance of the storage galactomannan in the establishment of plantlets of Sesbania virgata was investigated following the study of survival of plantlets with or without endosperm, as well as the diuturnal variations of the sucrose catabolism enzymes activity. The plantlets grown in the darkness with endosperm survived 16 days longer than the plantlets without the storage organ. Independent variations among the enzymes were detected, suggesting that the different enzymes are engaged in different physiological processes and, although sucrose is their common substrate, they take part in independent metabolic pathways.
invertase; source-sink relations; storage; sucrose synthase
