Protein Patterns of Developing Mitochondria at the Onset of Germination in Maize (Zea mays L.)

The respiration increase during seed imbibition and the onset of germination is usually accompanied by significant mitochondriogenesis. The latter process is manifested in characteristic development of organelle ultrastructure. Changes in cytochrome spectra and respiration sensitivity to the electron transport inhibitors seem to suggest some rearrangement in the respiration chain. An increase in the ratio of enzyme markers of mitochondrial matrix and inner membrane indicates the relative accumulation of matrix material. However, it is not clear whether these developmental changes reflect differential de novo synthesis of mitochondrial proteins or merely rearrangements within mitochondria pre-existing in dormant seeds. Two experimental approaches were initiated to answer this question. Quantitative immunochemical methods were applied in order to demonstrate changes in protein ratios and/or the origin of new antigens. Dual-label techniques were combined with SDS-disc-electrophoresis to evaluate de novo formation of polypeptides. The results show that alterations in the protein patterns may be attributed to the differential changes in synthesis and degradation rates of several groups of mitochondrial polypeptides