TIMING OF THE PROTEIN-CHANGES DURING PHASE-TRANSITION IN CINERARIA

Shoot apices in vegetative plants of cineraria cv. Cindy Dark Red grow ing in the juvenile (5 and 6 leaves initiated), transition (7 leaves) and competent (9, 12, 16, 20 and 22 leaves) phases of development were labelled with [S-35]-methionine. Proteins were then extracted from th e shoot tips and separated by SDS-PAGE and examined through autoradiog raphy. Clear and consistent quantitative differences in banding intens ity between juvenile, transition and competent phases were observed. F our bands appear to change in banding intensity at the time of phase t ransition. Two proteins (21 and 23 kD) were found to be predominant in the juvenile phase with their intensities degrading during phase tran sition to almost extinct in competent plants. In contrast, two protein s (40 and 53 kD) were found to increase in intensity from the transiti on to the competent phase, and then their expression remained almost c onstant in competent plants as they grew older. No qualitative differe nces in protein were apparent between plants in different phases.