CHANGES IN MESSENGER-RNA AND PROTEIN DURING RIPENING IN APPLE FRUIT (MALUS-DOMESTICA BORKH CV GOLDEN DELICIOUS)

Poly(A)+ RNA was extracted from cortical tissue of apple fruit (Malus domestica Borkh. cv Golden Delicious), and in vitro translation products were analyzed by two-dimensional gel electrophoresis. As fruit internal ethylene concentration increased from a basal level of 0.0 to 0.1 microliter per liter to 1 to 5 microliters/ liter, substantial changes in the pattern of in vitro translation products were observed. More subtle changes were observed as fruit continued to ripen and internal ethylene concentration increased to 80 to 100 microliters/liter. Overall, the levels of at least six mRNAs were found to increase, while one mRNA decreased. Analysis of proteins extracted from ripening fruit indicated that the level of at least three proteins increased with ripening.