3.3. Petal peptidase activity
The total peptidase activity in the petals of ethylene-treated
flowers was significantly higher than those of the control flowers,
already by the end of the 24 h ethylene treatment (Fig. 2). A significant
difference was also observed on days 2–5 after ethylene
treatment (Fig. 2). An increase in peptidase activity was found in
petals of ethylene-treated flowers, between day 3 and 4 (Fig. 2;
statistics not shown).
Fig. 1. Protein levels in petals of Dendrobium cv. Khao Sanan flowers. (A) soluble protein,
(B) insoluble protein, and (C) total protein. Flowerswere treated with air () or
0.4LL−1 ethylene (). Protein content was determined using the standard Bradford
assay. Values aremeans±SE (n = 3). Statistical differences between treatments
(P < 0.05) for each day are indicated by a different letter.