Lycopene, one of the main carotenoids in tomato, is mainly
responsible for the red colour and varies with different ripening
stages. To test the effect of melatonin on tomato fruit
ripening during postharvest, preliminary experiments were
carried out to determine the appropriate concentrations of
melatonin. In this study, we found that lycopene accumulated
significantly in melatonin-treated fruits (Fig. 1C) at
17 d after melatonin treatment (DAT), compared with the
control (CK). A 5.1-fold increase was observed with 50 μM