Potato (Solanum tuberosum L.) is an important staple food worldwide. However, its growth has been heavily suppressed by salt stress. The molecular mechanisms of salt tolerance in potato remain unclear. It has been shown that the tetraploid potato Longshu No. 5 is a salt-tolerant genotype. Therefore, in this study we conducted research to identify salt stress response genes in Longshu No. 5 using a NaCl treatment and time-course RNA sequencing. The total number of differentially expressed genes (DEGs) in response to salt stress was 5508. Based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, it was found that DEGs were significantly enriched in the categories of nucleic acid binding, transporter activity, ion or molecule transport, ion binding, kinase activity and oxidative phosphorylation. Particularly, the significant differential expression of encoding ion transport signaling genes suggests that this signaling pathway plays a vital role in salt stress response in potato. Finally, the DEGs in the salt response pathway were verified by Quantitative real-time PCR (qRT-PCR). These results provide valuable information on the salt tolerance of molecular mechanisms in potatoes, and establish a basis for breeding salt-tolerant cultivars.

The production of potato (Solanum tuberosum L.) faces a severe challenge due to the salinization of arable land worldwide. The cultivation of salt-tolerant potatoes is of great significance to ensure food security. In this study, two cultivars of ‘Longshu 5’ and ‘Qingshu 9’ were compared for physiological responses to salt stress, and then the salt tolerance of the two cultivars were assessed via principal component analysis. Furthermore, the Na⁺, K⁺, and Ca²⁺ flux of the cultivars under salt stress was recorded. Finally, the expression levels of ion transport-related genes and transcription factors in salt-tolerant cultivars were explored under NaCl stress. The results showed that the seven physiological indicators of salt tolerance were differed between the cultivars. Interestingly, soluble protein and sugar were early responsive to salt stress than proline in the salt-tolerance cultivar. Peroxidase and superoxide dismutase activity were significantly different in ‘Longshu 5’ under NaCl stress and without being significantly different in ‘Qingshu9’. In addition, the salt tolerance of ‘Longshu 5’ was more tolerant than ‘Qingshu 9’ based on principal component evaluation. Meanwhile, the strong efflux of Na⁺, the stability of K⁺, and the high absorption of Ca²⁺ in ‘Longshu 5’ indicated salt adaption mechanisms in the salt-tolerant potato. In addition, we found that ion transport-related genes and transcription factors, such as StSOS1, StNHX4, StAKT1, StNAC24, and StCYP707A, played a role in the salt tolerance of ‘Longshu 5’. In conclusion, the salt-tolerant potato can regulate physiological substances to adapt to salt stress, and ion transport related genes and transcription factors play a role in improving salt tolerance.

Fresh fruits and vegetable products are easily perishable during postharvest handling due to enzymatic browning reactions. This phenomenon has contributed to a significant loss of food. To reveal the physiological changes in fresh-cut potato tubers at the molecular level, a transcriptome analysis of potato tubers after cutting was carried out. A total of 10,872, 10,449, and 11,880 differentially expressed genes (DEGs) were identified at 4 h, 12 h and 24 h after cutting, respectively. More than 87.5% of these DEGs were classified into the categories of biological process (BP) and molecular function (MF) based on Gene Ontology (GO) analysis. There was a difference in the response to cutting at different stages after the cutting of potato tubers. The genes related to the phenol and fatty biosynthesis pathways, which are responsible for enzymatic browning and wound healing in potato tubers, were significantly enriched at 0–24 h after cutting. Most genes related to the enzymatic browning of potato tubers were up-regulated in response to cut-wounding. Plant hormone biosynthesis, signal molecular biosynthesis and transduction-related genes, such as gibberelin (GA), cytokinin (CK), ethylene (ET), auxin (IAA), jasmonic acid (JA), salicylic (SA), and Respiratory burst oxidase (Rboh) significantly changed at the early stage after cutting. In addition, the transcription factors involved in the wound response were the most abundant at the early stage after cutting. The transcription factor with the greatest response to injury was MYB, followed by AP2-EREBP, C3H and WRKY. This study revealed the physiological changes at the molecular level of fresh-cut potato tubers after cutting. This information is needed for developing a better approach to enhancing the postharvest shelf life of fresh processed potato and the breeding of potato plants that are resistant to enzymatic browning.

Potato is the fourth-most important food crop around the world, and most of the potatoes are used for foodstuffs and starch products. The aim of this paper is to identify the volatile compounds and metabolites in potatoes with different processing properties. The results showed large differences of volatile and metabolite compounds such as 2,4-Heptadienal and rhoifolin in potatoes and indicated the potential regulations between volatile compounds and metabolites. Moreover, the differences in volatile and metabolite compounds were compared between fresh eating and processing type potatoes. Compared to process type potatoes, fresh eating potatoes contained a higher proportion of aldehyde and alcohol compounds, but being lower in hydrocarbon, furan, and ketone compounds. Moreover, the different expressed metabolites were involved in the metabolism of amino acids, flavone and flavanol biosynthesis, and tryptophan metabolism. The Random forest showed that the fresh eating and processing type potatoes could be distinguished by the content of amino acids and phenols.

Senescence impacts plant growth and yields in tetraploid potatoes (Solanum tuberosum L.). Because of their homogenous tetraploid features, it is a major challenge to understand the genetic basis and molecular mechanisms of senescence. Here, we identified a novel central senescence regulator (Nicotinate-nucleotide pyrophosphorylase QPT/StNADC) through map-based cloning. Overexpression of StNADC^Z3 accelerated senescence in the late-senescence variety, with NAD content declining by around 40%. CRISPR/Cas9-induced StNADC mutant cr2–11 exhibited extremely early senescence, and the NAD content was reduced by 87% along with reduced chlorophyll content and photosynthesis. Moreover, the downstream products of the NAD synthesis pathway, such as NaMN, NAD, or niacin, can refresh the cr2–11 mutant to grow normally. Further, the transcriptomics and metabolomics data unveiled that the disrupting of StNADC impairs NAD metabolism, accelerating plant senescence through multiple biological levels. Our results show that StNADC is indispensable for NAD synthesis, and targeting the StNADC-mediated NAD synthesis pathway could be a useful strategy to regulate senescence in potato breeding preprograms.

Soil salinization is increasing globally, causing yield losses, especially in irrigated agriculture. Rhizosphere microorganisms can improve plant salt tolerance, but evidence in potato remains limited. In this study, rhizosphere microbial community diversity and structure differed markedly between salt-tolerant and salt-sensitive potato under saline and non-saline conditions. Under field salinity, salt-tolerant genotypes retained more network-associated rhizosphere taxa, particularly Pseudomonadota members, and showed enrichment of Pseudomonas. From tolerant rhizospheres, Pseudomonas aeruginosa BK43, a salt-tolerant, growth-promoting strain, was isolated. In sterilized saline field soil, the salt-tolerant phenotype was abolished in the absence of microbial inoculation, while introduction of BK43 significantly restored growth (plant height ~10.8 to ~16.3 cm; leaf area ~16 to ~80 cm²), demonstrating a direct microbial contribution to salt tolerance. In non-sterilized saline soil, enrichment of this bacterium accelerated early post-emergence growth of tolerant plants without affecting seedling emergence. Salt tolerance was also conferred to an otherwise sensitive genotype following pre-colonization with BK43, with root lipid peroxidation reduced by ~43% and higher chlorophyll content under salt stress. Multi-omics analyses linked BK43-mediated protection to basal activation of host defense and metabolic pathways under non-stress conditions and salt-amplified phenylpropanoid, redox-related, and stress-signaling responses after salt exposure.