3.8 Postharvest trehalose treatment up-regulates PpINH1and increases chilling resistance of peach fruit
CI in peaches occurred after two weeks of storage at 5 °C. Visible flesh
browning was observed on day 21 of storage, and at day 28 severe CI was
observed. In contrast, peaches treated with trehalose did not exhibit
substantial CI after 21 or 28 days of storage (Figure 6a, 6b ).
Sucrose content in trehalose-treated fruit was significantly higher than
in untreated control fruit throughout the 28-day storage period
(Figure 6c ). In control fruit, VIN activity increased nearly
2-fold during 28 days of cold storage (Figure 6d ), whilePpVIN2 expression increased more than 500-fold by the
21st day of storage (Figure 6e ). In
trehalose-treated fruit, VIN activity also increased during storage, but
remained lower than in the control fruit. PpVIN2 expression also
increased with storage time but was significantly lower than in control
fruit on days 21 and 28. Expression of PpINH1 in control fruit
decreased significantly during storage, as did expression in
trehalose-treated fruit, but PpINH1 expression in treated peaches
remained significantly higher throughout cold storage (Figure
6f ).