Quantitative Ultrastructure and Protein Composition of Date Palm (Phoenix Dactylifera) Seeds: A Comparative Study of Endosperm vs. Embryo

Abstract

Comparative studies on the ultrastructure and protein composition of the embryo and endosperm of date palm (Phoenix dactylifera L.) were conducted. Cells of the embryo cotyledon and endosperm function in reserve storage and contained cell walls, nuclei, and cytoplasm rich in lipid and protein bodies. Morphometric analysis from light and electron micrographs showed that the cell walls of the endosperm occupied 65% of the total cell volume, but only 6% in the embryo. The protein bodies of the endosperm accounted for 11%, whereas those of the embryo occupied more than half of the total cell volume. The volume of organelles and organelle‐free cytoplasm in the endosperm was negligible, suggesting that most of the extractable endosperm proteins are localized in the protein bodies. Extractable proteins in the embryo may come from cytoplasm, protein bodies, and other organelles. The endosperm contains relatively lower amounts of proteins than does the embryo. Proteins extracted from both tissues were compared using SDS‐polyacrylamide gel electrophoresis, tube gel isoelectric focusing, and two‐dimensional electrophoresis. Proteins of both the tissues were heterogeneous in molecular mass and charge. The majority of the proteins were similar in molecular mass and charge in the two tissues, suggesting that most of the storage proteins are probably the same. However, there were also several embryo‐ and endosperm‐specific proteins apparent in both the first‐ and second‐dimension gels. The endosperm‐specific proteins may play an important role in germination and seedling development.

Anatomy, histochemistry and ultrastructure of seed and somatic embryo of Acrocomia aculeata (Arecaceae)

“…In Euterpe edulis (Panza et al, 2004), where there are no protein and lipid reserves in the embryo, but only in the endosperm, the protein bodies are similar to the ones found in the endosperm of A. aculeata. There were several embryo-and endosperm-specific proteins in Phoenix dactylifera; and the latter are consistent with the hypothesis that the endosperm is a possible source of hydrolytic enzymes during germination and seedling development (Sekhar and DeMason, 1988).…”

Identification and immunocytochemical localization of ?-galactosidase in resting and germinated date palm (Phoenix dactylifera L.) seeds

“…The embryo contains a single cotyledon made up of protoderm, provascular and ground-parenchyma cells, all of which contain protein and lipid bodies (DeMason and Thomson 1981; Chandra Sekhar and DeMason 1988). The endosperm is composed of uniform, living cells with massively thickened, hard cell walls and is 94% store reserves by volume.…”

“…The endosperm is composed of uniform, living cells with massively thickened, hard cell walls and is 94% store reserves by volume. In order of abundance, these reserves are mannan-rich cell-walls (65%), lipid bodies (18%) and protein bodies (11%) (Chandra Sekhar and DeMason 1988). Date endosperm walls consist of three layers which differ in their ultrastructural features and staining characteristics: middle lamella, thickened outer wall, and thin inner wall (De-Mason et al 1983).…”

Anti-inflammatory Effect of Hydroalcoholic Extract of the Washingtonia filifera Seeds in Carrageenan-Induced Paw Edema in Rats

“…The genus Washingtonia is indigenous to California but has been cultivated in Iran and elsewhere. Previous phytochemical study of this species detected lipids, proteins, leucoanthocyanins, flavonols, C-glycosylflavones, and flavonoid sulfates (29)(30)(31). While the flavonoid sulfates are not widely distributed in the plant kingdom, they occur in many members of the Palmae, especially in important palm genera such as Washingtonia (32).…”