Ethylene plays a key regulatory role during ripening of
many fruits by regulating carotenoid lycopene synthesis,
conversion of starch to sugars, and enhancing cell walldegrading
enzyme activity. Exogenous melatonin could
promote tomato fruit ripening during postharvest life, thus
positively impacting ethylene production and signalling.
We can infer that melatonin-induced fruit ripening events,
such as lycopene accumulation, cell wall degradation and
volatiles biosynthesis, are dependent on ethylene biosynthesis
and signal transduction (Fig. 7). The findings expanded
our understanding of melatonin function in ripening tomato
fruits, providing evidence that melatonin is involved in fruit
maturation.