Comparative proteomic analysis of seeds before and after dormancy release in Carex schmidtii Meinsh

Carex schmidtii Meinsh. is an ecologically valuable wetland plant whose seeds exhibit deep dormancy and low natural germination. Although cold stratification can effectively promote dormancy release, the molecular mechanisms remain poorly understood. Investigating protein alterations and associated biosynthetic and metabolic pathways during dormancy release will enhance our understanding of this process. Seeds were subjected to cold stratification (4°C, dark) for varying durations. The 15-day treatment, which increased germination from 9.33% to 70.00%, was selected for omics analysis. Subsequently, using proteomics techniques, we compared the proteomic changes in C. schmidtii seeds before and after dormancy release induced by the cold stratification treatment. A total of 2004 proteins were detected in C. schmidtii seeds before and after dormancy release, among which 1,338 were identified as differentially expressed proteins (DEPs). The majority of DEPs were implicated in carbohydrate-related metabolic processes during dormancy release, suggesting that energy deficiency may contribute to the low germination rates of C. schmidtii seeds. Notably, a pronounced response from the ubiquitin-proteasome system (UPS) was also observed during dormancy release. Furthermore, photosynthesis-related proteins were significantly downregulated following dormancy release, implying that this wetland species may have evolved specific adaptations to cope with dark germination environments. This study reveals the molecular mechanisms by which low-temperature stratification regulates dormancy release in C. schmidtii seeds and provides insights for further investigation into the pathways, key genes and proteins involved in seed dormancy release of this species.