Cell Wall Metabolism in Ripening Fruit

Abstract
Mature ''Bartlett'' pear (P. communis) fruits were ripened at 20.degree. C. Fruits at different stages of ripeness were homogenized, and extracts of the low speed pellet (crude cell wall) were prepared. These extracts contained polygalacturonase, pectin esterase and activity against seven p-nitrophenyl glycoside substrates. Polygalacturonase, .alpha.-galactosidase and .alpha.-mannosidase increased in activity as the fruit ripened. Cellulase and activities against pear wall xylan and arabinan were absent from the extracts.