Comparative transcriptome and metabolomic survey reveal key pathways involved in the control of the chilling injury disorder superficial scald in two apple cultivars, ‘Granny Smith’ and ‘Ladina’

ABSTRACT: The low temperature normally applied to prevent fruit decay during the storage of apples, can also triggers the onset of a chilling injury disorder known as superficial scald. In this work, the etiology of this disorder and the mechanism of action of two preventing strategies, such as the application of 1-MCP and storage at low oxygen concentration in ‘Granny Smith’ and ‘Ladina’ apple cultivars was investigated. The metabolite assessment highlighted a reorganization of specific secondary metabolites, in particular flavan-3-ols (catechin, epicatechin and procyanidin B) and unsaturated fatty acids (oleic acid, linoleic acid and linolenic acid), while the genome-wide transcriptomic analysis grouped the DEGs into four functional clusters. The KEGG pathway, GO enrichment analysis, together with the gene-metabolite profiling interactome, showed as the treatment with 1-MCP prevented the development of superficial scald by actively promoting the production of unsaturated fatty acids, especially in ‘Granny Smith’. ‘Ladina’ was instead more susceptible to superficial scald, and characterized by a higher accumulation of very long chain fatty acids (VLCFAs). Storage at low oxygen concentration stimulated a higher accumulation of ethanol and acetaldehyde together with the expression of genes involved in anaerobic respiration, such as malate and alcohol dehydrogenase and pyruvate decarboxylase in both cultivars. Moreover, in ‘Granny Smith’ apple, the expression of three members of the VII subgroups of ERF genes, encoding for elements coordinating the acclimation process to hypoxia in plants was observed. The global RNA-Seq pattern also elucidated a specific transcriptomic signature between the two cultivars, validating the effect of the different genetic background in the control of this disorder.

ORGANISM(S): Malus domestica

PROVIDER: GSE216082 | GEO | 2023/03/29

REPOSITORIES: GEO