Differentiated protein synthesis with polysomes from Petunia ovaries before fertilization.

Polysomes from cross-, self- and unpollinated ovaries have been injected in Xenopus laevis eggcells. The synthesised proteins have been identified by means of gel-electrophoresis. It appeared that few hours after pollination the protein pattern of the pollinated ovary has changed in comparison with that of unpollinated ones. However, in this early stage, there is only little difference found in the protein pattern of selfed and crossed ovaries. From 12 h after pollination and onwards, the difference between pollinated and unpollinated ovaries becomes very obvious, as does also the difference between crossed and selfed ovaries. At 24 h after pollination many different proteins exist in crossed and selfed ovaries. From 32 h to 48 h after pollination the crossed ovaries differentiate further on, whereas the ovaries after self-pollination show more and more proteins which were also found in the unpollinated ovaries of that age. Possible explanations and hypothesis for these phenomena are discussed as well as the probable occurrence of signal(s) arriving from the stigma or the style at the ovary.