The LmMYB94-LmCHS module regulates dynamic flower coloration changes by regulating flavonoid biosynthesis in Lonicera maackii

The unique flower color transition of Lonicera maackii provides critical phenological guidance for determining the optimal medicinal harvesting period in ornamental woody plants. However, the molecular mechanisms underlying its color dynamics are unclear. Herein, we comprehensively utilize multi-omics, biochemical and molecular biology techniques to investigate the regulatory mechanisms of flavonoid biosynthesis. We firstly established the regulatory network involved in the biosynthesis of flavonoids and the dynamics of flower coloration in L. maackii through integrated transcriptome and metabolome analysis. In addition, we identified the key gene encoding for chalcone synthase (LmCHS), which is localized in the cytosol and nucleus via confocal microscopy imaging. Most importantly, overexpression of LmCHS in tt4 mutants partially rescued the mutant phenotype and increased flavonoid content. Furthermore, we demonstrated that LmMYB94 can bind and activate the expression of LmCHS through yeast one-hybrid assay and dual-luciferase reporter gene assay. These results indicate that the LmMYB94-LmCHS module regulates dynamic flower coloration changes by regulating flavonoid biosynthesis in Lonicera maackii . Collectively, this provides fresh perspectives on the mechanisms of dynamic flower color changes and facilitate molecular breeding in trees. • Multi-omics analysis to establish the regulatory networks of flavonoid biosynthesis L. maackii ’s dynamic flower coloration. • LmCHS is a crucial gene involved in flavonoid synthesis, as confirmed by functional verification experiments. • LmCHS-LmMYB94 regulatory module was first characterized in L. maackii , facilitating genetic breeding.