Storage protein changes during zygotic embryogenesis in interior spruce.

The major storage proteins isolated from protein bodies of embryo tissues of interior spruce Picea glauca (Moench) Voss/Picea engelmanii Parry had apparent molecular weights of 41, 35, 33, 24 and 22 kD. Minor proteins of 30 and 27.5 kD were also observed. Based on their solubility characteristics, the 41 kD protein was identified as a water and buffer-soluble albumin, and the 35, 33, 24 and 22 kD proteins were characterized as buffer-insoluble, high salt-soluble globulins. Two-dimensional electrophoresis revealed each protein was composed of several isoelectric variants. Developmentally specific accumulation of storage proteins was observed during embryogenesis. The 41 kD protein only accumulated during the later stages of cotyledon maturation, whereas the other storage proteins began to accumulate during the early stages of embryo development. All storage proteins showed major accumulations during cotyledon maturation.