Abstract
BACKGROUND: Gleditsia sinensis is a significant economic and ecological tree species in Guizhou Province, offering high economic value and substantial development opportunities. Reproduction of G. sinensis primarily involves seed propagation, requiring a yearly supply of high-quality seeds for production. Nonetheless, seeds are characterised by a hard and dormant composition, and the precise molecular mechanism behind dormancy release remains unclear. This study conducted physiological, transcriptomic, and metabolomic analyses on G. sinensis seeds at different stages of low-temperature stratification to elucidate the molecular regulatory mechanisms involved in seed dormancy release. RESULTS: The content of soluble protein gradually decreases during the stratification and germination process, while the content of soluble sugar shows an upward trend. The sucrose content gradually decreases during the process of dormancy release in stratification and germination. The seeds of G. sinensis are jointly regulated by nutrient and energy metabolism, osmotic regulation, and the antioxidant enzyme system during the stratification and germination process. Through the analysis of gibberellin (GA) metabolism and sugar synthesis metabolic pathways, differentially expressed genes (DEGs) related to GA synthesis such as GA3, kaurenoic acid oxidases (KAO), gibberellin 20 oxidase (GA20ox), and gibberellin 2 oxidase (GA2ox), as well as DEGs related to carbohydrate metabolism such as Amylose (AMY), phosphofructokinase (PFK), and sucrose synthase (SUS), were screened. Correlation analysis identified 8 key DEGs regulating the GA synthesis pathway, including KAO and GA2ox, along with 23 DEGs associated with starch and sucrose metabolism, such as UDP-glucose pyrophosphorylase 2 (UGP2). CONCLUSIONS: The mechanism of dormancy release in G. sinensis seeds involves the synthesis and metabolic regulation of GA and sucrose. Key differential genes were identified, providing a theoretical basis for exploring the molecular regulatory mechanisms during seed dormancy release and germination.