Superficial scald is a serious physiological disorder in “Yali” pear (Pyrus
bretschneideri Rehd. cv. Yali) after long-term cold storage. Changes in
superficial scald, ethylene production, α-farnesene and phenylpropane
metabolism with associated gene expression in “Yali” pear treated with
and without (control) 1-methylcyclopropene (1-MCP) were investigated.
Compared with the control group (without 1-MCP), 1-MCP (1.0 μl L?1
)
significantly lowered the superficial scald index after 180 days of cold storage.
During cold storage and shelf life, the contents of α-farnesene, conjugated
trienols, chlorogenic acid, and epicatechin in the peel were reduced, while
quercetin was enhanced in 1-MCP-treated fruit, and the expression of genes
associated with ethylene synthesis (ACS1, ACO1), receptors (ETR2, ERS1) and
signal transduction (ERF1), α-farnesene metabolism (AFS1, HMGR2, GST7),
phenolic biosynthesis (PAL1, C4H1, C4H2, HCT3, 4CL2, C3H), and oxidases
(PPO1, PPO5, and LAC7) were significantly downregulated by 1-MCP. These
results suggested that the onset and development of superficial scald was
closely related to the ethylene receptor, conjugated trienols, chlorogenic acid
and epicatechin and related genes expression in “Yali” pear.