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An ultrastructural study on the reserves stored in cotyledons and endosperm and on their utilization after germination has been carried out in Cercis siliquastrum seeds. The observations have shown that all the cotyledonal reserves of proteins and lipids are used during seedling growth. However, inside the endosperm cells only the protein reserves are depleted, and large quantities of lipids remain undigested. In both cell walls and intercellular spaces of the endosperm cells huge masses of polysaccharide reserves are stored. However, only the polysaccharides inserted in the cell walls are dismantled, while those located in the intercellular spaces are not attacked by the lytic enzymes. Some hypotheses regarding the possible roles of those endospermic non-nutritional materials in the strategies of seed germination and seedling growth are suggested.

Rice coleoptiles grow under anoxia. When the ultrastructure of anoxic coleoptile cells was examined, it was seen that most organelles maintain their integrity, with the exception of peroxisomes (unspecialized type). The lack of O2 greatly reduced the number of these organelles and altered the ultrastructure of the remaining ones. To examine the effect of O2 on peroxisome development in more detail, coleoptiles grown in air were transferred to N2 and anoxic coleoptiles were transferred to oxygen. Marker enzyme activity was measured in entire coleoptiles as well as in the isolated organelles. As expected, anoxia greatly depressed enzyme activity when imposed from the beginning of the germination process, while it had a lesser effect when imposed for only two days on aerobic seedlings. When coleoptiles were grown constantly under N2, the density of the organelles was 1.216 g/cm3, while the corresponding aerobic organelles showed a buoyant density of 1.241 g/cm3. When transferred to air the anoxic peroxisomes reached the intermediate density of 1.227 g/cm3. The results confirm the particular sensitivity of rice peroxisomes to O2 availability.