GENE-EXPRESSION DURING 2 ALTERNATIVE PATHWAYS OF OVARY DEVELOPMENT IN PISUM-SATIVUM - FRUIT-DEVELOPMENT AND OVARY SENESCENCE

Pea ovaries are induced to enter a fruit development pathway involving physiological and morphological changes by pollination or application of plant growth regulators. In the absence of these stimuli, ovaries stop growing and enter an alternative pathway of senescence that leads to their degeneration. We have used two dimensional polyacrylamide gel electrophoresis in search of molecular changes underlying fruit development and ovary senescence at the level of total accumulated proteins, newly synthesized proteins, and translatable RNA populations. We have found changes in gene expression during the processes of ovary formation and ovary senescence. Stimuli that induce fruit set do not appreciably alter the overall patterns of synthesized proteins or translatable RNAs, indicating that fruit development is apparently a natural continuation of ovary formation. However, ovary senescence is an alternative pathway that involves the presence of new RNA messengers and proteins as well as the disappearance of others. These changes were detected earlier than any morphological or structural changes could be observed in the ovary.