Sucrose utilization during ovule and seed development of Gasteria verrucosa (Mill.) H. Duval as monitored by sucrose synthase and invertase localization

The development of Gasteria verrucosa ovules and seeds seems to follow a pa ttern of growth in which the majority of carbohydrates is first used in the sporophytic tissue (nucellus, integuments, and arillus) around the gametop hyte-derived cells. After fertilization the carbohydrates are used for furt her development of the arillus and seed coat. During the next stage carbohy drates are directed to develop the endosperm, followed by carbohydrate inve stment in the developing embryo and in storage products. This utilization p attern is deducted from a localization study on sucrose synthase and invert ase. These two enzymes break down imported sucrose and are in that perspect ive used as markers for carbohydrate transport since diffusion is expected to be induced towards cells and tissues with high sucrose-hydrolyzing activ ities.