Evidence against the formation of fast diffusing substances preceding fertilization in Petunia

Differentiated protein and RNA metabolism in the ovaries of Petunia after cross- and self-pollination has been described previously (Linskens 1973, Deurenberg 1976a, b, 1977). It was observed that the differentiation was altered after pollination long before the tips of the pollentubes reached the ovary. From this observation was concluded that recognition signals had to be emitted from the stigma or the style in order to evoke the differential metabolic processes which result in a differentiated protein metabolism with regard to the total amounts of proteins synthesised as well as the protein pattern. Two possible explanations were supposed for these phenomena: and electrical signal (Linskens & Spanjers 1973) and fast diffusing substances. Fast diffusing substances are known in the plant kingdom in relation to rhemonastic movements as well as phototropic reactions (Umrath 1959, Lea 1976).