Network of multi-omics reveals the mechanism of russeting under
rainwater in pears
Abstract
Russeting occurs via the epidermal suberin accumulation model in the
phenol-ester protection system in pears, especially under excessive
rainfall. To clarify the role of rain in the russeting mechanism, we
applied multi-omics (transcriptome, metabolome, and proteome) integrated
analysis from three colored pear cultivars grown under two rainfall
conditions, including a no rain control (C) and a rain-abundant (R)
treatment. Broad alterations occurred in 29 overlapping differentially
expressed genes (DEGs) involved in the response to stress and secondary
metabolite biosynthesis. Three overlapping differentially expressed
proteins (DEPs) and seven differentially expressed metabolites (DEMs)
were identified among the three comparison groups. Cross-comparison of
mRNA and protein data revealed co-expression of DEGs and DEPs. Suberin
and phenylpropane were markedly enhanced, while cutin biosynthesis and
fatty acid elongation were depressed in russet pears under R. In russet
pears, the triacontane associated with wax composition was abruptly
missing. Moreover, The PpyHHT1 (103966555) gene and encoded protein HHT1
(694406379), which acts as a ‘bridge’ between phenol- and ester-
polymerization, had significantly upregulated expression. Collectively,
we provide a comprehensive model of the molecular russeting mechanism,
which provides powerful insight into russeting and shows the plasticity
of plant defenses to cope with the harsh natural environment.