As key regulators of the Jasmonates (JAs) signal transduction pathway, JAZ protein, and MYC transcription factors are imperative for plant response to external environmental changes, growth, and development. In this study, 18 StJAZs and 12 StMYCs were identified in potatoes. Their chromosomal position, phylogenetic development, gene structure, and promoter cis-acting parts of the StJAZ genes were analyzed. In addition, Protein–Protein Interaction (PPI) network analysis of StJAZ and StMYC gene families and yeast two-hybrid assay demonstrated that five StMYCs can interact with 16 StJAZs, which provides new insights into the operation mechanism of StJAZs and StMYCs in JA signal response. Moreover, we explored the expression profiles of StJAZs and StMYCs genes in different tissues and during abiotic stresses by RNA-seq data. Based on the PPI network and transcriptome data, the genes StJAZ11, StJAZ16, and StMYC6 were chosen for further qRT-PCR study under salt or mannitol treatment. Under mannitol-induced drought or salinity treatment, the expression patterns of StMYC6, StJAZ11, and StJAZ16 were different, indicating that the JAZ protein and MYC transcription factor may be engaged in the response of potatoes to abiotic stress, which opened up a new research direction for the genetic improvement of potatoes in response to environmental stress.

Potato stolon research has emphasized stolon-tip tuberization, leaving the transition of basal axillary buds into subterranean stolons poorly characterized. Using cv. Désirée, we characterized this transition at IS0 immediately before soil covering and at 5, 7, 9, and 11 d thereafter (IS5, IS7, IS9, and IS11) by morphological, histological, and transcriptomic analyses. At IS5, external morphology changed little, although internal tissue reorganization was evident. During IS7–IS9, buds progressively reoriented, enlarged basally, and established a subterranean lateral axis. By IS11, white stolons had formed and entered post-initiation elongation without visible stolon-tip swelling. PCA separated IS0 and IS11 from the intermediate stages, and adjacent-stage differential expression identified the largest DEG sets in IS0–IS5 and IS9–IS11. Direction-resolved GO and KEGG enrichment distinguished successive transitions: early oxidative/defense and phenylpropanoid-related categories; intermediate changes in transport, photosynthesis, redox metabolism, and cytoskeletal organization; and later enrichment of translation-, proteasome-, and cell-division-related categories. Mfuzz clustering provided a complementary overview of broad temporal trajectories, including IS5-associated C6, distinct C3 and C5 patterns during initiation, and IS11-associated C2. RT-qPCR profiles of StBRC1b, StWUS, StWOX5, StCCD8, StSP6A, and StSP3D were broadly consistent with the RNA-Seq trends. These results establish a time-resolved framework for soil-covering-induced stolon initiation and subsequent elongation.