Multi-omics analysis reveals specific modifications associated with reduced chilling injury in bell pepper fruit by methyl jamonate

Bell pepper is prone to chilling injury during cold storage. In this study, the plant hormone, methyl jasmonate (MeJA), which can stimulate the expression of plant defense genes, was used to investigate its effects on the transcriptome, metabolome and proteome after 6 days at 4 ℃. Differentially expressed (DE) mRNAs that were identified with plant hormone signaling included the transcription factor MYC2, and those associated with antioxidant properties, membrane lipids and cell wall modification, fruit quality and an important transcription factors pathway -- calmodulin-binding transcription activator - c-repeat-binding factor - transcription factor ICE1 (CMAT-CaCBF1A-ICE1). Effects on the proteome analysis were mainly associated with glutathione metabolism, biosynthesis of unsaturated fatty acids and fatty acid metabolism. Differentially expressed metabolites were identified as acids, phenolics, and capsaicin. Our study suggests that MeJA treatment mitigates chilling injury of bell peppers though inhibiting the MYC2-JA signaling pathway, enhancing the ASA-GSH cycle, reducing membrane lipid damage, suppressing cell wall disassembly, and activating the CMAT-CBF-ICE pathway. These results provide a theoretical basis for further study on chilling injury of bell pepper fruit.