Transcriptomic and Physiological Analyses of 1,4-Dimethylnaphthalene-Induced Sprout Suppression in Potato (Solanum tuberosum L.) During Storage

Potato (Solanum tuberosum L.) tubers suffer nutritional and quality deterioration during storage owing to sprouting, which can cause economic losses. Conventional sprout-inhibition approaches are often constrained by chemical residue risks or variable control efficiency. In this study, the cultivar ‘Longshu No. 10’ was used to investigate the effects of 1,4-dimethylnaphthalene (hereinafter abbreviated as DMN) on tuber sprouting and associated molecular responses during storage. Five DMN concentration treatments were applied: 0 μL/kg (control), 10 μL/kg, 20 μL/kg, 80 μL/kg, and 160 μL/kg. Tubers were stored in a three-dimensional crate-shelf system. Combined phenotypic observations, transcriptome sequencing, and physiological measurements showed that DMN markedly suppressed tuber sprouting, with the 80 and 160 μL/kg treatments completely suppressing sprouting during the 60-day evaluation period. Tuber firmness increased with increasing DMN concentration, whereas respiration rates showed an overall downward trend. Transcriptomic profiling identified the largest number of differentially expressed genes (37,754) in the comparison between the control and the 80 μL/kg treatment (T0 vs. T3). Gene Ontology enrichment analysis highlighted metabolic processes and stimulus-response pathways, while Kyoto Encyclopedia of Genes and Genomes enrichment analysis identified starch and sucrose metabolism as a key candidate pathway within carbohydrate metabolism. Collectively, these findings suggest that changes in starch and sucrose metabolism and reducing sugar accumulation may be associated with DMN-induced sprout suppression in potato tubers. The results provide physiological and transcriptional insights into the response of ‘Longshu No. 10’ tubers to DMN treatment and a basis for further investigations to clarify the associated regulatory processes and evaluate its potential application in potato storage management across different cultivars, storage conditions, and storage periods.