Many hormones can impact
lycopene biosynthesis. Recently, advances have been made in
the regulation mechanism of ethylene on lycopene biosynthesis
in tomato fruit. The Nr mutant (a single amino acid
change in Nr ethylene receptor) exhibits reduced ethylene
sensitivity and accumulates low amounts of lycopene in ripened
fruits (Lanahan et al., 1994). Moreover, PSY is under
strong positive ethylene control during ripening (Klee and
Giovannoni, 2011). In our research, melatonin treatment
enhanced lycopene accumulation (Fig. 1A) and ethylene production
(Fig. 5A), implying that melatonin may increase the
content of lycopene by impacting ethylene biosynthesis and
signalling.