Proteomic profile associated with the m aturation of somatic embryos of Euterpe edulis under polyamine treatments in material derived from a single mother plant

Euterpe edulis is of ecological and economic relevance and is currently threatened with extinction. Its vulnerability to extinction, combined with the recalcitrant nature of its seeds, justifies the search for alternative reproduction techniques. Somatic embryogenesis is an alternative propagation method that is subdivided into distinct phases. Maturation is a crucial phase in the process for the successful regeneration of somatic plantlets. Therefore, this study aimed to investigate the effects of putrescine and spermidine, applied individually or in combination, on the maturation of E. edulis somatic embryos originating from a single mother plant. To this end, concentrations of putrescine (0, 500, 1000, or 1500 µM) and spermidine (0, 150, 200, 250, 300, or 350 µM) were analyzed. The highest number of somatic embryos (71.67) and coleoptilar embryos (67.67), both per embryogenic callus, was obtained in maturation medium supplemented with spermidine (350 µM) + putrescine (1500 µM). In this treatment, 313 differentially accumulated proteins (DAPs) were identified, with 63 up -accumulated and 250 down -accumulated compared to the control (without supplementation). Functional annotation by orthology suggests that among the DAPs, some proteins stand out for being potentially associated with the following biological processes: cell defense, energy metabolism, carbon/nitrogen balance equilibrium, and regulation of the cellular redox environment. It is concluded that spermidine (350 µM) + putrescine (1500 µM) enhances the formation of E. edulis somatic embryos derived from a single mother plant and the transition of these embryos to the coleoptilar development stage. These responses were accompanied by proteomic changes suggesting conserved biological processes potentially associated with embryo maturation.