To fully understand how melatonin changes cell wall
structure in tomato fruit, five cell wall structure-related
genes were investigated. The expression of cell wall structure-
related genes (SlPE1, SlTBG4, SlPG2a, SlExp1 and
SlXTH5) following 50 μM melatonin treatment was generally
higher than untreated controls. The expression of the
SlPG2a gene, which is involved in the hydrolysis of pectin,
was sharply increased by almost 5-fold in M50-fruits when
compared with CK-fruits (Fig. 3C). The result that SlPG2a
expression was up-regulated in the melatonin-treated fruits
was consistent with reduced pectin levels in these tomato
fruits.