Structure, Composition and Physiological State of the Endosperm of Phoenix dactylifera L

Abstract

The date endosperm consists of living cells with the same general cellular structure throughout the seed. The major storage products, as shown by histochemical staining, are lipid, stored as numerous small lipid bodies which fill the cytoplasm, and protein, as large but variably-sized protein bodies. Nuclei are present but lack large amounts of heterochromatin. Plastids and mitochondria are present but infrequently seen and have poorly developed internal membranes. No endoplasmic reticulum or dictyosomes are present before or after hydration. The cell wall is thick except in areas of pit fields and consists of three layers which differ in their staining behaviour: middle lamella, thickened wall and inner wall. Both the endosperm and embryo of the imbibed seed undergo aerobic respiration, but the embryo respires at a more rapid rate than does the endosperm. A small area of the endosperm around the distal pole of the cotyledon shows histochemically detectable levels of succinic dehydrogenase.