Multiomics comprehensive analysis of pre-storage low-temperature on cowpea metabolism

Abstract

The purpose of this study is to investigate the effect of low temperature on the storage quality of cowpea and explore its regulatory mechanism. In this study, we performed transcriptome, metabolome, and chromatin accessibility analyses of pericarp tissues of cowpeas stored at 20 °C with and without exposure to 4 °C for 2 d. The results showed that low temperature induced the expression of genes related to membrane lipid metabolism (PLC, PLA1, LOXs), cell wall metabolism (PG, β-glu), and antioxidant pathways (POD, PPO, SOD). Lipid metabolites such as 9-oxo-10E,12Z-octadecadienoic acid, 9-hydroperoxy-10E,12,15Z-octadecatrienoic acid, 13S-hydroperoxy-9Z,11E-octadecadienoic acid, and flavonoid metabolites such as liquiritigenin, daidzein, glyceollin III accumulated under low-temperature treatment. Low-temperature treatment also affected cold perception mechanisms and cell signal transduction, altering the expression of genes related to calcium signaling (CPK, CML), the MAPK cascade pathway (MPKKK17/18, MKS1, AMPK), and the ICE-CBF-COR pathway (CBF1, ICE1). Low-temperature treatment impacted transcription factors of the AP2/ERF, MYB, NAC, WRKY, and LOB families. These findings suggest that pre-storage at low temperatures induced the expression of genes involved in membrane lipid metabolism, cell wall metabolism, antioxidant pathways, cold signal transduction pathways, and corresponding transcription factors and their target genes. Treatment effects on genes and metabolites may be associated with chilling injury of cowpeas.