Calmodulin-like proteins (CMLs) serve as core components in plant calcium signal transduction pathways, and they extensively modulate plant growth, development, and adaptive responses to various abiotic stresses. In this study, we cloned the StCML19 gene from potato and generated stable transgenic Arabidopsis thaliana lines constitutively expressing this gene to investigate its functional role under drought stress. Transcriptome analysis revealed that StCML19 was up-regulated under drought conditions. Phenotypic assays showed that overexpressing StCML19 notably increased the seed germination rate and root length of transgenic Arabidopsis under mannitol-induced osmotic stress, and greatly improved the plant survival rate under severe soil drought stress. Physiological analysis showed that when put under drought stress, transgenic plants had higher proline content, better SOD, CAT, and POD activities, and significantly less malondialdehyde (MDA) accumulation than wild-type plants. In addition, overexpression of StCML19 led to greater plant sensitivity to exogenous ABA, with inhibited root growth and delayed seed germination as indicators. Conclusively, this study is the first to make sense of the biological function of potato StCML19 in the drought stress response and views StCML19 as a promising candidate gene for the genetic improvement of drought-tolerant potato varieties.

Calmodulin-like proteins (CMLs) are key mediators of plant calcium signaling and participate in abiotic stress responses, but their functions in potato remain poorly understood. Here, we systematically identified 62 StCML genes in potato via genome-wide analysis, which were phylogenetically clustered into seven clades and unevenly distributed across 12 chromosomes. Synteny analysis indicated that tandem and segmental duplications drove StCML family expansion, while promoter cis-element analysis suggested their involvement in phytohormone signaling and stress responses. Transcriptomic data showed StCMLs exhibited tissue-specific expression (high in roots, flowers, stamens) and were transcriptionally induced by drought, salt, and abscisic acid (ABA). Heterologous overexpression of StCML50 in Arabidopsis enhanced drought tolerance, as evidenced by improved germination, root elongation, and survival compared to wild-type. Physiologically, StCML50 overexpression increased proline accumulation, boosted antioxidant enzyme (SOD, CAT, POD) activities, and reduced malondialdehyde (MDA) levels under drought. Additionally, transgenic lines showed increased ABA sensitivity. This study provides insights into the potato CML gene family’s evolution and regulatory mechanisms, offering a valuable genetic resource for potato stress tolerance improvement.

Glutathione S-transferases (GSTs) are an important family of enzymes involved in plant detoxification, maintenance of redox homeostasis, and responses to abiotic stresses. However, the evolutionary characteristics and functional roles of the potato GST pan-gene family have not yet been systematically investigated at the pan-genome level. In this study, based on high-quality potato genomes constructed from 45 diploid accessions, GST gene family members were systematically identified, and their evolutionary features and expression patterns were analyzed. Phylogenetic analysis classified the GST family into six subgroups, among which the soft-core gene StGST7 and the near-core genes StGST8 and StGST16 were assigned to the Phi and Tau subgroups, respectively. Selection pressure analysis indicated that five StGST genes may have undergone positive selection, whereas most of the remaining genes were mainly subjected to purifying selection. Structural variation significantly affected the expression of StGST42 and the conserved domains of its encoded protein. Expression profiling revealed that GST family members exhibited clear tissue-specific expression patterns and responded differentially to drought, salt, high temperature, ABA, and IAA treatments. Co-expression network analysis revealed significant positive and negative correlations between multiple transcription factors and StGST gene expression, suggesting their potential involvement in the coordinated regulation of StGST genes. Further analyses demonstrated that StGST7 was significantly differentially expressed under multiple stress conditions, and its heterologous expression enhanced yeast tolerance to salt and drought stress. This study revealed the evolutionary characteristics and potential functions of the potato GST gene family and provides a theoretical basis for elucidating the molecular mechanisms underlying its regulation of environmental adaptation.

Continuous potato monoculture induces soil degradation and yield reduction. While crop rotation alleviates continuous cropping obstacles, its microbial regulatory mechanisms underlying soil quality improvement remain poorly understood. Through field trials in arid and semi-arid regions of Northwest China, we systematically analyzed the effects of five rotation systems (potato - broad bean rotation, PB; potato - maize rotation, PM; potato - fallow, PF; potato - oil flax rotation, PO; and potato - quinoa rotation, PQ) on soil microbial community structure and soil quality, along with tuber yield, with continuous potato cropping (PP) as the control. A Soil Quality Index (SQI) was developed through principal component analysis by integrating multiple soil physicochemical indicators. All rotations significantly increased SQI (21.5 %-37.7 %) and tuber yields by 2.1 %-16.2 % compared to PP, with PO achieving the peak yield enhancement (16.2 %). Random forest modeling identified available phosphorus (AP), potassium (AK), and soil organic matter (SOM) as primary SQI influencing factors. Microbial analysis revealed rotations enriched Acidobacteriota (6.1 %-38.5 %) while reducing Anthophyta abundance (8.8 %-154.2 %). Weighted gene co-expression network analysis demonstrated bacterial networks exhibited higher node complexity but lower connectivity than fungal networks. Key bacterial family (1.1 % of taxa) including Pyrinomonadaceae (positively correlated with TK/AP, r < -0.50, P = 0.01) and Chitinophagaceae (yield-associated, r = 0.52, P = 0.03) were identified by Zi-Pi analysis as microbial indicators of soil fertility and productivity. The superior performance of the potato-oil flax rotation is attributed to enhanced SOM accumulation, improved nutrient availability (AP, AK), and the selective stimulation of functional bacterial groups promoting nutrient cycling. This work advances understanding of rotation-mediated soil remediation by systematically characterizing microbial interaction networks, providing actionable insights for sustainable potato cultivation in arid and semi-arid regions.

Plant AT-rich sequence and zinc-binding proteins (PLATZs) act as critical modulators of plant growth, development, and responses to environmental stressors. Nevertheless, the PLATZ gene family (StPLATZs) has not yet been systematically characterized in potato, and this study seeks to identify members and prioritize genes associated with abiotic stress. A total of 13 StPLATZ genes were identified in the potato genome and classified into three distinct subfamilies based on phylogenetic analysis. Expression profiling and qRT-PCR analysis indicated that several StPLATZ genes responded to abiotic stress treatments. Yeast-based functional analysis suggested that Soltu06G018660 improved tolerance to PEG-induced osmotic stress, indicating its potential involvement in osmotic stress responses. These results provide candidate genes and hypotheses for future functional validation in potato. Further in-depth research on StPLATZs may contribute to potato stress-tolerance breeding.

Carotenoid cleavage dioxygenases (CCDs), crucial non-heme pigment oxygenases regulating plant stress responses, remain poorly characterized functionally in potato despite extensive research on this gene family. In this study, genome-wide analysis identified 12 StCCD family genes in potato, which were classified into five subfamilies. Gene structure and conserved motif analyses revealed significant intra-subfamily conservation, the gene promoter region is rich in abiotic stress and hormone response elements. Transcriptome analysis demonstrated that StNCED2 expression level was dramatically up-regulated under drought stress. Further functional characterization revealed that StNCED2 overexpression in Arabidopsis significantly enhanced drought tolerance. Transgenic lines exhibited reduced malondialdehyde (MDA) accumulation and reactive oxygen species (ROS) levels, along with elevated proline (Pro) content and enhanced antioxidant enzyme activities compared to wild-type (WT) plants. Furthermore, qRT-PCR analysis demonstrated that multiple stress response and ABA synthesis related genes were markedly up-regulated in transgenic plants under drought conditions. Additionally, StNCED2 overexpression increased ABA sensitivity, as evidenced by shorter root lengths and delayed germination in the presence of exogenous ABA. High performance liquid chromatography (HPLC) analysis revealed that under drought stress, ABA levels in transgenic lines increased significantly by 26.5% (OE9), 20.7% (OE11), and 69.2% (OE14) compared to WT plants (p < 0.01). Collectively, these findings demonstrate that StNCED2 positively regulates drought tolerance in Arabidopsis through enhanced ABA biosynthesis.

Phytochrome-interacting factors (PIFs) were initially recognized as pivotal regulators of plant light signaling pathways. However, mounting evidence suggests that PIFs also exert significant influences on plant development and responses to stress. Here, we identified seven PIF genes in the potato genome and conducted comprehensive characterizations through phylogenetics, gene structure, conserved motif, synteny, chromosomal location analyses and cis-regulatory element. Transcriptome data and gene expression analysis showed that the StPIF4 gene was markedly induced by mannitol-induced water deficit. Additionally, the StPIF4 protein was primarily localized in the nucleus and plasma membrane. In order to explore the function of the StPIF4 gene under mannitol-induced water deficit, the StPIF4 gene was cloned, and several StPIF4 overexpression (OE) lines (OE-8, OE-10, and OE-11) and three RNA interference (RNAi) transgenic lines (RNAi-5, RNAi-9, and RNAi-11) were obtained. The OE lines displayed notable enhancements in various growth parameters such as plant height, leaf number, branch number, fresh weight, dry weight, total root length, root surface area, number of root forks, and number of root tips under mannitol-induced water deficit compared to the wild-type (WT) lines, whereas these parameters were significantly decreased in the RNAi lines. The activities of antioxidant enzymes (SOD, POD, CAT) and the accumulation of proline and soluble sugars were also significantly increased under mannitol-induced water deficit, whereas the levels of thiobarbituric acid reactive substances (TBARSs) and reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and O2-, were significantly reduced in the OE lines compared to WT plants under mannitol-induced water deficit. Moreover, the stomatal aperture of the leaves and the water loss rate in the leaves of the OE lines were significantly reduced under mannitol-induced water deficit compared to the WT plants, whereas for the RNAi lines they were significantly increased. In addition, the overexpression of StPIF4 also upregulated expression of drought-responsive genes and ABA content under mannitol-induced water deficit. Collectively, these results highlight the positive role of the StPIF4 gene in enhancing potato tolerance to mannitol-induced water deficit by decreasing stomatal aperture, enhancing ROS scavenging and mitigating oxidative damage.

The JASMONATE-ZIM DOMAIN (JAZ) repressors are crucial proteins in the jasmonic acid signaling pathway that play a significant role in plant growth, development and response to abiotic stress (such as drought, heat, salinity, and low temperature). In this study, we identified 26 potato JAZ genes and classified the corresponding predicted proteins into five subfamilies. All potato JAZ proteins exhibited the expected conserved TIFY (TIF[F/Y] XG) and JAZ domains. Additionally, we identified several stress-responsive cis-regulatory elements, notably ABRE and ARE in the promoters of the JAZ gene family. Whole transcriptome and gene family expression analysis identified StJAZ23 as a key gene responding to drought stress in the root tissues of the Atlantic (Atl) and Qingshu 9 (QS9) potato cultivars. The StJAZ23 gene was cloned, and subcellular localization analysis suggested that the StJAZ23 protein was mainly localized in the nucleus and cell membrane. This study confirmed that StJAZ23 plays a role in drought stress by analyzing several StJAZ23 overexpression (OE-3, OE-5, and OE-6) and RNA interference (RNAi-3, RNAi-6, and RNAi-13) transgenic potato lines. The OE lines displayed significantly increased StJAZ23 expression compared to wild-type (WT) plants, while RNAi lines exhibited significantly reduced expression. The total root length, root tip count, and root surface area were significantly enhanced in OE lines under drought stress, compared to WT plants, whereas RNAi lines showed significant reductions. StJAZ23 overexpression also increased the activities of SOD, POD, CAT, and root vigor under drought stress and JA and ABA hormone levels were also significantly increased in roots under drought stress. These results highlight the positive role of the StJAZ23 gene in enhancing potato resilience to drought stress.

Water scarcity has been a persistent challenge impeding the progress of the potato industry in northwest China. This field study was conducted in the arid and semi-arid regions of northwest China, specifically in Dingxi, Gansu Province, during the years 2018 and 2019, within a rain exclusion shelter. The 'Hermes' potato variety was selected as the experimental material. According to different field water capacity (FWC), six treatments were set, FWC85% was 85 %similar to 95 %, FWC75% was 75 similar to 85 %, FWC65% was 65 %similar to 75 %, FWC55% was 55 %similar to 65 %, FWC45% was 45 %similar to 55 %, and NI was no irrigation. The experimental setup involved a combination of ridging, film mulching, and drip irrigation to investigate the impacts of different FWC levels on growth characteristics, physiological traits, photosynthetic attributes, tuber yield, and water use efficiency (WUE). The results highlighted that maintaining an FWC above 65 % significantly enhanced plant height, stem diameter, number of branches, leaf area, dry matter accumulation, and tuber yield. Notably, the FWC75% treatment exhibited the highest levels of dry matter accumulation and tuber yield, showing increments of 235.87 %similar to 312.72 % and 198.99 %similar to 257.61 %, respectively, compared to the no-irrigation treatment. Analysis of physiological and photosynthetic characteristics indicated that an FWC range of 55 %similar to 65 % marks a critical threshold where the limiting factor for the net photosynthetic rate shifts from stomatal to non-stomatal. Water use efficiency (WUE) declined with increasing FWC, while irrigation water use efficiency (IWUE) initially rose and then declined with FWC increments. The FWC65% treatment stimulated potato root growth, enhanced water absorption in 40 similar to 80 cm soil depths, and effectively boosted IWUE. In summary, maintaining an FWC above 65 % proves pivotal for optimizing potato yield in the semi-arid conditions of northwest China, with the most favorable tuber yield observed at FWC levels of 75 %similar to 85 %. This study seeks to provide a theoretical foundation and technical backing for enhancing water-efficient potato cultivation practices in northwest China.

Genomic analysis is crucial for understanding the evolutionary history, phylogenetic relationships, and effective conservation of plant species. Casearia kurzii is an important medicinal plant of the genus Casearia, but its complete chloroplast genome has not previously been reported, limiting genetic studies and conservation efforts. In this study, we assembled and annotated the complete chloroplast genome of C. kurzii using Illumina sequencing technology and conducted a comparative genomics analysis with 14 closely related species to clarify its phylogenetic position within Casearia. The chloroplast genome was 157,998 bp, showing a typical quadripartite structure. Key findings included: (1) the loss of the rpl22 gene at the IR boundary; (2) the identification of 60 simple sequence repeats (SSRs) and (3) the discovery of five candidate molecular markers for species-level identification. Phylogenetic analysis revealed that C. kurzii formed a strongly supported monophyletic clade (100% bootstrap support) with C. velutina, C. decandra, and C. glomerata, this clade originated approximately 15.8 million years ago. This study provides molecular tools for accurate identification and conservation of C. kurzii and related species, laying the foundation for exploring adaptive evolution within Casearia and advancing comparative genomics research.

Glutathione S-transferases (GSTs) play crucial roles in crop stress tolerance through protection against oxidative damage. In this study, we conducted genome-wide identification and expression analysis of the GST gene family in the autotetraploid potato cultivar Cooperative-88 (C88) using bioinformatic approaches. We identified 366 GST genes in the potato genome, which were classified into 10 subfamilies. Chromosomal mapping revealed that StGSTs were distributed across all 12 chromosomes, with 13 tandem duplication events observed in three subfamilies. Analysis of protein sequences identified 10 conserved motifs, with motif 1 potentially representing the GST domain. Analysis of cis-acting elements in the StGSTs promoter regions suggested their involvement in stress response pathways. RNA-seq analysis revealed that most StGSTs responded to both drought stress and DNA demethylation treatments. Quantitative PCR validation of 16 selected StGSTs identified four members that showed strong responses to both treatments, with distinct expression patterns between drought-tolerant (QS9) and drought-sensitive (ATL) varieties. Transient expression assays in tobacco demonstrated that these four StGSTs enhanced drought tolerance and may be regulated through DNA methylation pathways, though the precise mechanisms require further investigation. These findings provide a theoretical foundation for understanding the response and epigenetic regulation of potato GST genes under drought stress.

PYR/PYL/RCAR proteins are abscisic acid (ABA) receptors that play a crucial role in plant responses to abiotic stresses. However, there have been no research reports on potato PYL so far. In this study, a potato PYL gene named StPYL16 was identified based on transcriptome data under drought stress. Molecular characteristics analysis revealed that the StPYL16 protein possesses an extremely conserved PYL family domain. The tissue expression results indicated that the StPYL16 is predominantly expressed at high levels in the underground parts, particularly in tubers. Abiotic stress response showed that StPYL16 has a significant response to drought treatment. Further research on the promoter showed that drought stress could enhance the activation activity of the StPYL16 promoter on the reporter gene. Then, transient and stable expression of StPYL16 in tobacco enhanced the drought resistance of transgenic plants, resulting in improved plant height, stem thickness, and root development. In addition, compared with wild-type plants, StPYL16 transgenic tobacco exhibited lower malondialdehyde (MDA) content, higher proline accumulation, and stronger superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. Meanwhile, StPYL16 also up-regulated the expression levels of stress-related genes (NtSOD, NtCAT, NtPOD, NtRD29A, NtLEA5, and NtP5CS) in transgenic plants under drought treatment. These findings indicated that the StPYL16 gene plays a positive regulatory role in potato responses to drought stress.

O-acetylserine (thiol) lyase is a pivotal enzyme in plant cysteine biosynthesis, which is crucial for promoting plant growth, development, and resisting abiotic stress. However, the related studies on the potato OASTL gene family (StOASTL) have not been reported. In the present study, we identified 11 members of the StOASTL gene family, conducting a thorough analysis encompassing chromosome distribution, protein physicochemical properties, gene structure, protein-conserved motifs, and gene replication events. Phylogenetic scrutiny delineated these 11 StOASTLs into five distinct subfamilies. Using RNA-seq from the Potato Genome Sequencing Consortium (PGSC), we investigated the expression profile of StOASTLs in different tissues of DM (double-monoploid) potato and under abiotic/biotic stress, hormone treatment, and biostimulant treatment. The results showed that one of the StOASTLs (Soltu09G024390) was differentially expressed under different abiotic stresses and hormone treatments. Our findings showcased the differential response of one StOASTL (Soltu09G024390) to a spectrum of abiotic stresses and hormone treatments. Soltu09G024390 was earmarked as a candidate gene and successfully cloned. Functional validation through yeast stress assays demonstrated that the heterologous expression of Soltu09G024390 bolstered yeast tolerance to salt and cadmium stresses. This study provides a theoretical basis for revealing the role of the StOASTL family in potato response to abiotic stress and valuable insights for further study of the biological functions of StOASTL.

The C3HC4 RING finger gene (RING-HC) family is a zinc finger protein crucial to plant growth. However, there have been no studies on the RING-HC gene family in potato. In this study, 77 putative StRING-HCs were identified in the potato genome and grouped into three clusters based on phylogenetic relationships, the chromosome distribution, gene structure, conserved motif, gene duplication events, and synteny relationships, and cis-acting elements were systematically analyzed. By analyzing RNA-seq data of potato cultivars, the candidate StRING-HC genes that might participate in tissue development, abiotic stress, especially drought stress, and anthocyanin biosynthesis were further determined. Finally, a StRING-HC gene (Soltu.DM.09G017280 annotated as StRNF4-like), which was highly expressed in pigmented potato tubers was focused on. StRNF4-like localized in the nucleus, and Y2H assays showed that it could interact with the anthocyanin-regulating transcription factors (TFs) StbHLH1 of potato tubers, which is localized in the nucleus and membrane. Transient assays showed that StRNF4-like repressed anthocyanin accumulation in the leaves of Nicotiana tabacum and Nicotiana benthamiana by directly suppressing the activity of the dihydroflavonol reductase (DFR) promoter activated by StAN1 and StbHLH1. The results suggest that StRNF4-like might repress anthocyanin accumulation in potato tubers by interacting with StbHLH1. Our comprehensive analysis of the potato StRING-HCs family contributes valuable knowledge to the understanding of their functions in potato development, abiotic stress, hormone signaling, and anthocyanin biosynthesis.

(1) Background: Potato is the most important tuber crop in the world that can contribute to food security. However, the crop has been shown to be sensitive to drought and its yields decline significantly during successive periods of stress. Drought triggers a number of responses in potato, ranging from physiological changes to fluctuations in growth rates and yields. In light of global climate change, it is important to understand the effects of thiamethoxam on potato growth and yield under drought conditions. (2) Methods: The objective was to evaluate the impact of thiamethoxam on improving drought resistance and yield of potato under drought conditions. The drought-tolerant and sensitive-genotypes Qingshu No. 9 and Atlantic were used for a two–year pot experiment. Potato seeds were coated with 70% thiamethoxam before sowing (treatment group (T)), with a control group without treatment (NT). Two experimental treatments were applied: normal irrigation (ND) and drought stress (D). (3) Results: The results showed that root length, plant yield, chlorophyll content and superoxide dismutase (SOD) activity significantly increased under both genotypes, while malondialdehyde (MDA) and proline (Pro) content were reduced under thiamethoxam under drought stress. The best indicators were obtained in the comprehensive evaluation for the T–D treatment, suggesting that the application of thiamethoxam under drought stress was more effective than normal irrigation. (4) Conclusions: Our results suggest that the application of thiamethoxam improves potato growth, thereby increasing drought tolerance and potato yield. However, thiamethoxam is a neonicotinoid pesticide, and the limitation of this study is that it did not explore the ecological effects of thiamethoxam, which need to be systematically studied in the future. Moreover, considering the potential risks of thiamethoxam to the environment, specific agronomic measures to effectively degrade thiamethoxam residue should be taken when it is applied in agricultural production.

Soilless cultivation of potatoes often utilizes organic coconut peat and inorganic vermiculite as growing substrates. The unique microbial communities and physicochemical characteristics inherent to each substrate significantly influence the microecological environment crucial for potato growth and breeding. This study analyzed environmental factors within each substrate and employed Illumina sequencing alongside bioinformatics tools to examine microbial community structures, their correlation with environmental factors, core microbial functions, and the dynamics of microbial networks across various samples. These included pure coconut peat (CP1) and pure vermiculite (V1), substrates mixed with organic fertilizer for three days (CP2 and V2), and three combinations cultivated with potatoes for 50 days (CP3, V3, and CV3—a 1:1 mix of coconut peat and vermiculite with organic fertilizer). Vermiculite naturally hosts a more diverse microbial community. After mixing with fertilizer and composting for 3 days, and 50 days of potato cultivation, fungal diversity decreased in both substrates. Coconut peat maintains higher bacterial diversity and richness compared to vermiculite, harboring more beneficial bacteria and fungi, resulting in a more complex microbial network. However, vermiculite shows lower bacterial diversity and richness, with an accumulation of pathogenic microorganisms. Among the 11 environmental factors tested, water-soluble nitrogen (WSN), total nitrogen (TN), available potassium (AK), total organic carbon (TOC) and air-filled porosity (AFP) were significantly associated with microbial succession in the substrate.The nutritional type composition and interaction patterns of indigenous microorganisms differ between vermiculite and coconut peat. Adding abundant nutrients significantly affects the stability and interaction of the entire microbial community, even post-potato cultivation. When using vermiculite for soilless cultivation, precise control and adjustment of nutrient addition quantity and frequency are essential.

Background Plant U-box (PUB) E3 ubiquitin ligases have vital effects on various biological processes. Therefore, a comprehensive and systematic identification of the members of the U-box gene family in potato will help to understand the evolution and function of U-box E3 ubiquitin ligases in plants. Results This work identified altogether 74 PUBs in the potato (StPUBs) and examined their gene structures, chromosomal distributions, and conserved motifs. There were seventy-four StPUB genes on ten chromosomes with diverse densities. As revealed by phylogenetic analysis on PUBs within potato, Arabidopsis , tomato ( Solanum lycopersicum ), cabbage ( Brassica oleracea ), rice ( Oryza sativa ), and corn ( Zea mays ), were clustered into eight subclasses (C1-C8). According to synteny analysis, there were 40 orthologous StPUB genes to Arabidopsis , 58 to tomato, 28 to cabbage, 7 to rice, and 8 to corn. In addition, RNA-seq data downloaded from PGSC were utilized to reveal StPUBs ’ abiotic stress responses and tissue-specific expression in the doubled-monoploid potato (DM). Inaddition, we performed RNA-seq on the ‘Atlantic’ (drought-sensitive cultivar, DS) and the ‘Qingshu NO.9’ (drought-tolerant cultivar, DT) in early flowering, full-blooming, along with flower-falling stages to detect genes that might be involved in response to drought stress. Finally, quantitative real-time PCR (qPCR) was carried out to analyze three candidate genes for their expression levels within 100 mM NaCl- and 10% PEG 6000 (w/v)-treated potato plantlets for a 24-h period. Furthermore, we analyzed the drought tolerance of StPUB25 transgenic plants and found that overexpression of StPUB25 significantly increased peroxidase (POD) activity, reduced ROS (reactive oxygen species) and MDA (malondialdehyde) accumulation compared with wild-type (WT) plants, and enhancing drought tolerance of the transgenic plants. Conclusion In this study, three candidate genes related to drought tolerance in potato were excavated, and the function of StPUB25 under drought stress was verified. These results should provide valuable information to understand the potato StPUB gene family and investigate the molecular mechanisms of StPUBs regulating potato drought tolerance.

The root system plays a decisive role in the growth and development of plants. The water requirement of a root system depends strongly on the plant species. Potatoes are an important food and vegetable crop grown worldwide, especially under irrigation in arid and semi-arid regions. However, the expected impact of global warming on potato yields calls for an investigation of genes related to root development and drought resistance signaling pathways in potatoes. In this study, we investigated the molecular mechanisms of different drought-tolerant potato root systems in response to drought stress under controlled water conditions, using potato as a model. We analyzed the transcriptome and proteome of the drought-sensitive potato cultivar Atlantic (Atl) and the drought-tolerant cultivar Qingshu 9 (Q9) under normal irrigation (CK) and weekly drought stress (D). The results showed that a total of 14,113 differentially expressed genes (DEGs) and 5596 differentially expressed proteins (DEPs) were identified in the cultivars. A heat map analysis of DEGs and DEPs showed that the same genes and proteins in Atl and Q9 exhibited different expression patterns under drought stress. Weighted gene correlation network analysis (WGCNA) showed that in Atl, Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG)-enriched pathways were related to pyruvate metabolism and glycolysis, as well as cellular signaling and ion transmembrane transporter protein activity. However, GO terms and KEGG-enriched pathways related to phytohormone signaling and the tricarboxylic acid cycle were predominantly enriched in Q9. The present study provides a unique genetic resource to effectively explore the functional genes and uncover the molecular regulatory mechanism of the potato root system in response to drought stress.