Insulin-induced changes in metabolism-related proteins during maize germination

Insulin regulates a wide range of metabolic processes in mammals, such as homeostasis and the breakdown of glucose. Recently, the existence of an insulin-related growth factor in maize (ZmIGF) and a possible receptor for this growth factor has been reported. This peptide exerts effects on plant growth and promotes germination by activating the target of rapamycin (TOR) signaling pathways, which is similar to the insulin response in mammals. In this study, we analyzed the insulin response in maize embryos using a proteomic approach. Our results indicated that insulin modulates the expression of proteins involved in processes, such as storage protein degradation, protein processing, redox and desiccation stress, and glucose metabolism. The involvement of TOR signaling pathways was analyzed using the TOR inhibitor, rapamycin. The results showed that the modulation of these proteins by insulin is independent of the TOR pathway. These results indicated that insulin promotes changes in metabolism-related proteins to ensure successful germination in maize.