Proteomic Analysis of Somatic Embryogenesis in Cyclamen persicum Mill

Cyclamen persicum Mill. is a widely grown ornamental species that is clonally propagated by somatic embryogenesis. To better understand the biology of somatic embryo development in C. persicum, detailed proteomic (two-dimensional gel electrophoresis) and mass spectrometric analyses of somatic embryos at globular, torpedo, and germinating stages of development, along with nonembryogenic callus and zygotic embryos, were conducted. Of ~460 proteins resolved in two-dimensional gels, 35 proteins were differentially expressed and could be reproducibly displayed across an isoelectric focusing range of 5 to 8. Among those proteins, five were constitutively expressed, 13 were upregulated, nine were downregulated, and eight were deemed as novel proteins during the torpedo stage. A total of 35 protein spots were analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and only four proteins were identified and these were available in public protein databases. The remaining protein spots were subsequently analyzed by MALDI-TOF-TOF-MS, and six proteins were then identified. These findings suggested that specific proteins are involved in the regulation of somatic embryogenesis.