Trehalose‐6‐Phosphate Synthase VvTPS10 Regulates Cold Tolerance by Participating in the CBF Pathway and VvPUB19‐Mediated Ubiquitination in Grapevine

Cold stress is a major environmental factor limiting the sustainable development of the grape industry, severely impacting plant physiological metabolism and cellular integrity. While class II trehalose 6-phosphate synthases (TPS) lack TPS enzymatic activity, they play critical roles in plant adversity response regulation and sugar metabolism. Currently, the cold resistance mechanisms of class II TPS genes remain poorly characterised. In this study, we employed transgenic technology to elucidate the cold resistance function of cold-inducible VvTPS10. The silencing of VvTPS10 resulted in increased sensitivity to cold stress, whereas VvTPS10-overexpressing grape lines exhibited enhanced cold tolerance and elevated trehalose content. Our findings demonstrate that VvTPS10 modulates cold tolerance through the CBF pathway. We provided evidence that VvCBF1 transcriptionally activates VvTPS10 by binding to the DRE motif within its promoter. Protein interaction and ubiquitination assays confirm that the cold tolerance negative regulator VvPUB19 directly interacts with VvTPS10 and mediates its degradation. Furthermore, transcriptome analysis revealed that VvTPS10 influences sucrose metabolism, and direct experimental evidence demonstrated the interaction between VvTPS10 and VvSnRK1. Our study elucidates a novel regulatory mechanism of VvTPS10 modulating cold tolerance in grapevine, offering new perspectives for research on class II TPS function and plant cold tolerance.