Development of the endosperm of Myrsine laetevirens (Myrsinaceae). II. Formation of protein and lipid bodies

The sequence of events during protein and lipid deposition has been examined in the developing endosperm of Myrsine laetevirens using light and electron microscopy and chemical analyses. At 10–20 d after pollination (DAP), plastids contain starch grains and phytoferritin deposits in a crystalline arrangement. Phytoferritin disappears 30 DAP, when lipid bodies are formed via secretion from smooth endoplasmic reticulum. Rough endoplasmic reticulum and Golgi stacks are present in all stages of development but are particularly evident during protein deposition. Protein bodies arise from preexistent vacuoles or derive directly from Golgi vesicles. Deposition of the crystalloid proteins occurs between 40 and 50 DAP; the matrix proteins appear at 60–70 DAP. Analysis of fatty acids by gas‐liquid chromatography revealed that lipid accumulation follows a sigmoidal pattern. During the first analyzed stage (10 DAP), the fatty acid composition corresponds to structural membrane lipids. From 20 to 60 DAP, the dominant ...