Biochemical and histochemical detection of endoproteolytic activities involved in ovary senescence or fruit development in Pisum sativum

The appearance of endoproteolytic activities related to the senescence of unpollinated pea (Pisum sativum L. cv. Alaska) ovaries, or with fruit development induced by gibberellic acid (GA3), was examined simultaneously by biochemical and histochemical techniques using gelatin as substrate. Biochemical detection was carried out by gelatin‐containing sodium dodecyl sulfate (SDS)‐polyacrylamide gel electrophoresis. Histochemical detection was performed using a gelatin film technique. No differences in endopeptidase activity were found in extracts from non‐treated or developing ovaries during the two first days post‐anthesis. After day 3 non‐treated ovaries showed a marked increase in activity as well as two new bands with proteolytic activity, associated with the beginning of the senescence. At the same time a new activity was also located at the endocarp. In developing ovaries activity was only observed around vascular cells of the mesocarp at the end of the period studied (4–5 days post‐anthesis). Activity detected in the ovules was essentially the same in both GA3‐treated and non‐treated ovaries.