Application of a combination of physiology and metabolomics to reveal the mechanism of dormancy breaking in medicinal plant Dictamnus dasycarpus seeds

The dry root bark of Dictamnus dasycarpus (Rutaceae) is a common traditional Chinese medicine (TCM), known as Dictamni cortex. This TCM is primarily used in dermatology and the plant is mostly artificially cultivated. However, its seeds exhibit intrinsic physiological dormancy, making germination challenging and hindering rapid seedling production and breeding. A proposed method to address this issue entails treatment of Dictamnus dasycarpus seeds with 50 mg L -1 GA 3 , in conjunction with low-temperature stratification. This method resulted in improved germination compared to seeds merely soaked in distilled water. GA 3 accelerates the utilisation of storage substances in seeds, enhances enzyme activity and promotes the accumulation of endogenous GA 3 . Metabolomic analysis revealed that dormancy release is critically associated with sugar metabolism, the TCA cycle, phenylpropanoid biosynthesis and flavonoid biosynthesis pathways. Embryos mobilise lipids and accumulate amino acids, nucleotides and vitamins to initiate germination. In summary, GA 3 breaks dormancy by modulating hormones, refining lipid metabolism and accumulating key metabolites like malic acid and nucleotides. These findings provide a theoretical framework for the optimal utilisation of Dictamnus dasycarpus medicinal resources.