Changes in amylase activity during rose bud opening

Following homogenisation and centrifugation of rose petals (cultivar ‘Sonia’), amylolytic activity was found in the supernatant fraction and associated with the particulate matter, especially the starch granules. The latter activity was released into solution by treatment with non-ionic detergent. The activity in the supernatant fraction showed no significant change during the ageing of cut flowers, but the particulate activity increased. The release of activity from the starch-containing fraction was achieved more quickly with material isolated from stored roses than from fresh flowers. Properties of the enzyme derived from the starch fraction suggest that it is different to the soluble enzyme. The possible role of amylase in rose petal senescence is discussed.