Preliminary investigation on the mechanism of potato tuber dormancy release induced by combined treatment of bromoethane and gibberellin

Potato is a vital staple crop, and timely release of tuber dormancy is essential for improving emergence uniformity and yield. Although bromoethane (BE) has been shown to effectively break dormancy, subsequent sprout growth remains slow, limiting its broader application. To enhance sprouting efficiency, this study explored the combined effects of BE and gibberellin (GA₃) on dormancy release and subsequent sprout development in potato tubers. Transcriptomic analysis was conducted on samples collected seven days after treatment from three groups: BE alone, BE+GA3, and a water control (CK). The results revealed that the BE+GA3 treatment not only shortened the dormancy period and increased sprouting rate but also significantly promoted sprout elongation. Compared with the control, differentially expressed genes (DEGs) in the BE group were primarily enriched in hormone signal transduction, MAPK signaling, and plant-pathogen interaction pathways related to stress responses, whereas DEGs in the BE+GA3 group were significantly enriched in carbohydrate metabolism, DNA replication, primary metabolism, and secondary metabolite biosynthesis pathways. Moreover, key genes in the IAA pathway (AUX/IAA, GH3) and GA pathway (GIB1, TF) were markedly upregulated, while that of key genes in the ABA pathway (ABI1/2, PP2C) were significantly downregulated in the BE+GA3 group relative to CK, indicating that this combined treatment modulated hormone signaling pathways closely associated with dormancy release and sprouting. High-performance liquid chromatography (HPLC) analysis further showed that BE+GA3 treatment significantly increased GA3 and IAA levels while reducing ABA content, resulting in a decreased ABA/GA. Together, these findings suggest that the synergistic effect of BE and GA3 promotes dormancy release and sprout growth in potato tubers by regulating hormone signaling and metabolic pathways—elevating GA3 and IAA levels while suppressing ABA accumulation. This study elucidates the complementary mechanisms of BE and GA3 and provides both theoretical insights and practical strategies for regulating potato dormancy.