Degreening and chlorophyll loss can be induced by exogenous
ethylene in parsley (Amir-Shapira et al., 1987) and spinach leaves
(Yamauchi and Watada, 1991). Similarly, other authors (Gong and
Mattheis, 2003) have found high chlorophyllase (chlase) activity
in broccoli treated with exogenous ethylene, suggesting that ethylene
is responsible for the chlorophyll loss.