Comparative transcriptome analysis of genes related to tuberization in late and early maturing potato (Solanum tuberosum) cultivars.

Potato maturity is a complex and vital agronomic trait directly impacting yield, quality, and economic value. Despite its importance, the molecular regulatory networks governing potato maturity remain largely unexplored. In this study, the factors underlying maturity differences between early-maturing (KX23) and late-maturing (DN310) tetraploid potato cultivars were investigated for the first time under field conditions. Tuber yields, starch content, flowering time, maturity and the number of morphologically modified stolons and initiated tubers were measured, revealing that maturity differences between KX23 and DN310 are linked to the timing of tuberization processes. To explore the molecular basis of these differences, RNA-seq analysis was performed on hooked stolons, swollen stolons, and initiated tubers, identifying key pathways involved in tuberization. WGCNA and qRT-PCR further pinpointed critical genes contributing to these pathways. DEGs between the two cultivars were primarily enriched in secondary metabolite pathways. Notably, a significant overlap of DEGs between KX23 and DN310 across the three developmental stages was identified, with enrichment in carbohydrate metabolism pathways. In total, 28 candidate genes consistently involved in tuber induction and formation were identified. Based on their functions, a model explaining how KX23 achieves faster tuberization, shortening its maturity period, was proposed. These findings provide valuable insights into the molecular regulatory mechanisms of tuberization and maturity in potatoes.