Fig . 2 . Effects of salicylic acid concentration on ethylene-forming
enzyme (EFE) activity in detached rice leaves . Leaf segments
were pretreated with a saturating concentration of ACC
(10 mM) for 2 h and then treated with various concentrations of
salicylic acid . Ethylene production was assayed after 6 h incubation
in darkness . Bars represent standard errors (n = 4) .