Objective To investigate the regulatory mechanism underlying the effect of low-temperature treatment on the accumulation of active components in Veronica polita and clarify its regulatory mechanism. Methods Plants subjected to low-temperature treatment were analyzed through phenotypic observation, physiological and biochemical indices, transcriptome and metabolome analyses. Results Prolonged low-temperature treatment significantly increased the plant height, fresh weight and dry weight, as well as the root length of V. polita. The activities of superoxide dismutase (SOD) and peroxidase (POD), as well as the contents of total flavonoids, total phenols and total sugars first rose and then decreased. The contents of malondialdehyde (MDA) and chlorophyll increased, whereas chlorophyll fluorescence parameters decreased. The contents of total flavonoids and total phenols also first increased and then decreased. Transcriptomic analysis showed that the differentially expressed genes (DEGs) exhibited a stage-specific expression patterns. Pathways such as secondary metabolite biosynthesis, phenylpropanoid biosynthesis, metabolic pathways, and plant hormone signal transduction were significantly enriched. Three flavonoid synthesis-related genes (GT5, JOX2, HO1) and five phenol synthesis and metabolism-related genes (LAC3, AOX4, LPR2, AS1, MT-CO2) were identified. Metabolomic analysis indicated that the contents of quercetin, myricetin, and benzoic acid showed a trend of first increasing and then decreasing with the extension of treatment time. Integrated multi-omics analysis demonstrated that the core mechanism by which V. polita responds to low-temperature stress involves the precise reprogramming of the phenylpropanoid/flavonoid metabolic pathway. Conclusion Appropriatelow-temperature treatment promotes the accumulation of secondary metabolites in V. polita, thereby providing a foundation for further research into its functional genes.

Veronica polita Tenore  /  low-temperature stress  /  physiological indices  /  transcriptome  /  metabolome  /  quercetin  /  myricetin  /  benzoic acid