Multi-omics analysis revealed the effect of leucine treatment on nucleic acid metabolism and its potential mechanism in postharvest broccoli

Abstract

To understand the effects and potential regulatory mechanism of leucine treatment on nucleic acid metabolism in yellowing and senescence process of postharvest broccoli, an integration profiling of transcriptome and metabolome was performed. Results showed that 5 mM leucine treatment delayed the increase in malondialdehyde content and inhibited the degradation of DNA and RNA, thus prolonging the shelf life of postharvest broccoli. A total of 92 differentially expressed genes and 9 differentially accumulated metabolites associated with nucleic acid metabolism were identified. Leucine treatment promoted DNA replication and enhanced DNA repair, thereby increasing the genome integrity and stability. Furthermore, leucine treatment augmented transcription and pre-mRNA processing by upregulating the expression of RNA polymerases, transcription factors, and splicing factors. The metabolomics results showed that the building blocks of DNA and RNA in leucine-treated broccoli were increased. In addition, exogenous leucine promoted mRNA translation and its subsequent recycling of mRNA, which upregulated the related protein biosynthesis and enhanced the energy utilization efficiency. Furthermore, leucine treatment enhanced the formation of small interfering RNA by upregulating the transcription of RNA polymerases V, 1, 5, and 6, thus increasing the resistance of broccoli against RNA viruses. The results of this study shed light on nucleic acid metabolism in postharvest broccoli and its regulatory mechanism and provide a theoretical basis for studying broccoli preservation.