Pectinesterase, Polygalacturonase, Cx-Cellulase Activities and Softening of the rin Tomato Mutant1

Pectinesterase (PE), polygalacturonase (PG), and cellulase (Cx form) activities and softening of 4 physiological maturities were compared in normal and rin tomatoes ( Lycopersicon esculentum Mil cv. Rutgers). PG, PE, and Cx-cellulase activities increased during ripening of normal fruits. In rin fruits, PG activity was not detected, PE activity remained relatively constant, and Cxcellulase activity increased during ripening. The lack of softening in rin fruits appears to be associated with the lack of PG activity.