The current status of proteomic studies in somatic embryogenesis

Somatic embryogenesis includes the genetic reprogramming of somatic cells to acquire the embryogenic potency necessary to generate an embryo, which can develop into a whole plant. Acquisition of embryogenic capacity requires rigorous biochemical coordination that includes several metabolic and signal transduction pathways. Recent genomic and epigenetic studies in somatic embryogenesis have shown interconnection among signals associated with growth regulators, stress factors, and modulation of the genome structure. A broad range of key proteins, posttranslational modifications, protein turnover, and protein-protein interactions are common factors associated with the establishment of the necessary biochemical status of cells during the acquisition of the embryogenic potential. Recent proteomic studies have begun describing the molecular basis of somatic embryogenesis. However, the diversity of the embryogenic response among plant species makes it difficult to define key protein factors associated with embryogenic cultures or specific stages during the transdifferentiation of somatic embryos. In this chapter, we review the most prominent proteomic studies carried out in the past decade and discuss the contributions of proteomics studies to elucidating the molecular basis of somatic embryogenesis.