Overexpression of StBBX14 Enhances Cold Tolerance in Potato

Potato (<i>Solanum tuberosum</i> L.) is an important food crop, but low temperature affects the potato growth and yield. In this study, the expression level of <i>StBBX14</i> was significantly increased over 1 h and then gradually decreased under cold stress. The subcellular localization of the StBBX14 protein took place in the nucleus. The <i>OE-StBBX14</i> transgenic lines showed less leaf damage and significantly lower electrolyte leakage compared with the WT under cold stress, indicating that the overexpression of <i>StBBX14</i> in the potato enhanced the cold resistance. A transcriptome analysis showed that a total of 2449 and 6274 differentially expressed genes were identified in WT-1 h and WT-12 h, respectively, when compared with WT-0h. A Gene Ontology enrichment analysis revealed that photosynthesis, cell wall, thylakoid, transcription regulator activity, oxidoreductase activity and glucosyltransferase activity were significantly enriched in <i>OE-StBBX14</i> and WT. A total of 14 distinct modules were generated by a WGCNA analysis based on all differentially expressed genes (DEGs). Four major modules with cold-related genes were isolated. RT-qPCR analysis showed that the expression patterns of eight DEGs were consistent between the qPCR and RNA-seq. These findings illustrate that the <i>StBBX14</i> played an important role in cold stress in potato and provided a data basis for the genetic improvement of cold resistance traits of potato.