A causal role for ethene in raspberry fruit ripening

Different stages of raspberry fruit development were used to quantify fruit firmness, rate of ethene evolution and ripening rate. Firmness differences correlated with levels of ethene evolution and receptacle weight. Fruit respiration declined as ripening progressed. The activities of four cell-wall modifying enzymes: polygalacturonase (PG); pectin methylesterase (PME); Cx-cellulase (Cx); and beta-galactosidase (beta-gal.) increased during ripening and major isoforms were identified for each of the enzymes assayed. Application of exogenous ethene to green fruits enhanced ripening rate.