Glucose as a Signaling Cue Reprograms Carbon–Nitrogen–Sulfur Metabolism in Cherry Rootstock Roots

Exogenous glucose functions not only as a carbon source but also as a key signaling molecule involved in regulating root development and metabolism in plants. To elucidate the molecular mechanisms underlying this response in cherry rootstock (Prunus cerasus), we performed RNA-seq on lateral roots collected at 0, 6, 12, 24, 48, and 72 h after glucose treatment. Transcriptome profiling revealed a dynamic and sustained transcriptional reprogramming, with a total of 461 differentially expressed genes (DEGs) consistently altered across all post-treatment time points relative to the control (T0). Weighted gene co-expression network analysis identified five modules strongly correlated with glucose exposure, notably enriched for genes involved in nitrogen, carbon, and sulfur metabolism. Functional enrichment analyses further revealed a pronounced overrepresentation of pathways associated with nutrient utilization, as well as carbon fixation, glycolysis, amino acid biosynthesis, and stress-responsive processes such as glutathione metabolism and MAPK signaling. Intriguingly, key transcription factors and signaling components were consistently co-enriched across multiple functional categories, suggesting the presence of a tightly coordinated regulatory network that links sugar sensing to metabolic reprogramming, redox homeostasis, and developmental plasticity. Notably, glucose treatment induced both activation and repression of nitrogen-related genes in distinct co-expression modules, indicating fine-tuned modulation of nutrient uptake in response to carbon availability. Together, these findings suggest that exogenous glucose triggers a systems-level shift in root physiology, coordinating primary metabolism with stress adaptation and growth regulation through tightly interconnected carbon–nitrogen–sulfur metabolic circuits.