Somatic and zygotic embryos of Daucus carota L. display different protein patterns until conversion to plants.

Total protein patterns of different developmental stages of carrot zygotic and somatic embryos revealed by one- and two-dimensional gel electrophoresis were compared using statistical dissimilarity index matrix, and some major polypeptides were partially sequenced. In spite of similar morphology, the protein patterns of somatic embryos at the torpedo stage were clearly different from those of zygotic embryos. In particular, none of the proteins specific of zygotic embryos required for maturation, previously identified, were accumulated in somatic embryos, namely the daucin (a globulin-type storage protein), the RAB25 protein (a late embryogenesis abundant protein) (Dodeman et al. 1998), as well as a novel globulin of M(r) 30,000, that we proposed to name apiacin. Somatic plantlets and seedlings also showed different patterns. This discrepancy likely reflects culture conditions, since somatic embryos recover a protein pattern close to that of seedlings after conversion to plant and growth on a carbon-free medium.