The mechanism by which NO exerts its effect is
presumed to be by inhibiting ethylene action. It is
of interest that NO has a similar effect to that
obtained with low concentrations of the ethylene
antagonist, 1-methylcyclopropene (1-mcp). Ku et
al. (1999) found that the fumigation of strawberries
with 1-mcp at 5–15 nl l−1 for 2 h extended
the postharvest life but higher concentrations decreased
postharvest life. It is possible there is
some similarity in the mode of action of NO and
1–mcp. The concentration dependent nature of
the effect of NO on strawberries is consistent with
the beneficial/adverse effects found for NO in
animal systems (Moncada et al., 1991).