Potato, the fourth largest food crop in the world, stores nutrients in underground tubers. However, light exposure induces tuber accumulation of chlorophyll and toxic steroidal glycoalkaloids (SGAs); this unwanted trait called tuber greening causes a decline in potato quality and renders parts of tuber inedible. Despite progress in enzymatic cascades governing SGAs biosynthesis, the regulatory scheme of SGAs and chlorophyll metabolism in light-exposed tubers persists as a critical knowledge gap. Here, we identify that the blue light receptor StCRY1 plays a predominant role in light-induced tuber greening and SGA elevation, functioning as a light-controlled transcriptional switch for genes involved in SGAs and chlorophyll biosynthesis. We show that the transcription factor StHY5 acts downstream of StCRY1 to coregulate both chlorophyll and SGA metabolism. However, StMYB4, a transcription factor regulated by StHY5, promotes SGA synthesis by directly binding to SGA biosynthetic genes without affecting chlorophyll homeostasis. Furthermore, StCRY1 employs a dual strategy by modulating StMYB4 expression and physically interacting with StMYB4 to regulate its transcriptional activity. Collectively, these findings uncover a modularly coordinated control of SGA accumulation and chlorophyll biosynthesis by bifurcation of the StCRY1-StHY5 axis, providing a promising strategy to concurrently curb light-induced tuber greening and glycoalkaloids accumulation.

The plant hormone abscisic acid (ABA) is historically recognized as a tuberization stimulator, with exogenous application significantly enhancing potato tuber formation. However, the physiological significance of endogenous ABA signaling in tuberization and its underlying molecular mechanisms remain poorly understood. Here, by using ABA-insensitive hypermorphic StHAB1G276D-overexpression mutant and StHAB1 knockdown mutant, we demonstrate that ABA signaling is essential for normal tuber formation in potato. Blocking of ABA signaling by StHAB1G276D-overexpression reduces underground stolon sensitivity to leaf-derived tuber-inducing signals. Notably, StHAB1 directly interacts with the tuber-forming signal StSP6A and reduces its phosphorylation level. Transcriptomic and quantitative phosphoproteomic analyses proved that StHAB1G276D modulates gene expression and phosphorylation of key players in the tuberization pathway and gibberellic acid signaling. Collectively, our findings uncover a critical role of endogenous ABA signaling in potato tuber formation and identify a mechanism linking the conserved FLOWERING LOCUS T and ABA pathways, offering molecular insights for accelerating potato tuberization by modulating hormone signaling.

Pectobacterium parvum is an emerging phytopathogen causing aerial stem rot of potato. P. parvum has a broad host range, with Chinese cabbage as one of its important hosts. Through multi-omics analysis, we discovered a previously uncharacterized gene family highly expressed during in planta infection, designated the plant secondary metabolite-binding (PSMB) family. This family likely originated via horizontal gene transfer and underwent lineage-specific expansion in P. parvum, forming a four-paralog pathogenicity island. Structural modelling revealed that PSMB proteins resemble the rhizobial RhiA protein, though their function in phytopathogens has not been established. Biochemical assays demonstrated that the representative member, PSMB1a, binds defensive plant secondary metabolites (PSMs) with high affinity. PSMB1a binds the solanidine with submicromolar affinity (Kd = 0.103 μM) and exhibited approximately 100-fold higher affinity over salicylic acid (Kd = 9.23 ± 2.35 μM), indicating selectivity for specific PSMs. Functional studies demonstrated that PSMB1a enhances tolerance to defensive PSMs and contributes to virulence. Heterologous expression of PSMB1a in sister species P. polare enhanced PSM tolerance and virulence on Chinese cabbage, but suppressed bacterial proliferation under non-stress conditions. Conversely, deletion of the entire PSMB pathogenicity island in P. parvum attenuated virulence on potato stems, Chinese cabbage, and radish while increasing in vitro growth, confirming a trade-off between virulence contribution and basal fitness. These findings identify the PSMB family as a new class of virulence factors in Pectobacterium and reveal a specialized adaptive strategy in P. parvum that involves the binding of defensive PSMs to facilitate infection.

Potato (Solanum tuberosum L.) is cultivated worldwide for its underground tubers, which provide an important part of human nutrition and serve as a model system for belowground storage organ formation. Similar to flowering, stolon-expressed FLOWERING LOCUS T-like (FT-like) protein SELF-PRUNING 6A (StSP6A) plays an instrumental role in tuberization by binding to the bZIP transcription factors StABI5-like 1 (StABL1) and StFD-like 1 (StFDL1), causing transcriptional reprogramming at the stolon subapical apices. However, the molecular mechanism regulating the widely conserved FT-bZIP interactions remains largely unexplored. Here, we identified a TCP transcription factor StAST1 (StABL1 and StSP6A-associated TCP protein 1) binding to both StSP6A and StABL1. StAST1 is specifically expressed in the vascular tissue of leaves and developing stolons. Silencing of StAST1 leads to accelerated tuberization and a shortened life cycle. Molecular dissection reveals that the interaction of StAST1 with StSP6A and StABL1 attenuates the formation of the alternative tuberigen activation complex (aTAC). We also observed StAST1 directly activates the expression of potato GA 20-oxidase gene (StGA20ox1) to regulate GA responses. These results demonstrate StAST1 functions as a tuberization repressor by regulating plant hormone levels; our findings also suggest a mechanism by which the widely conserved FT-FD genetic module is fine-tuned.

Solanum commersonii(2n=2x=24,1EBN,Endosperm Balance Number),native to the southern regions of Brazil,Uruguay,and north-eastern Argentina,is the first wild potato germplasm collected by botanists and exhibits a remarkable array of traits related to disease resistance and stress tolerance.In this study,we present a high-quality haplotype-resolved genome of S.commersonii.The two identified haplotypes demonstrate chromosome sizes of 706.48 and 711.55 Mb,respectively,with corresponding chromosome anchoring rates of 94.2 and 96.9％.Additionally,the contig N50 lengths are documented at 50.87 and 45.16 Mb.The gene annotation outcomes indicate that the haplotypes encompasses a gene count of 39 799 and 40078,respectively.The genome contiguity,completeness,and accuracy assessments collectively indicate that the current assembly has produced a high-quality genome of S.commersonii.Evolutionary analysis revealed significant positive selection acting on certain disease resistance genes,stress response genes,and environmentally adaptive genes during the evolutionary process of S.commersonii.These genes may be related to the formation of diverse and superior germplasm resources in the wild potato species S.commersonii.Furthermore,we utilized a hybrid population of S.commersonii and S.verrucosum to conduct the mapping of potato freezing tolerance genes.By combining BSA-seq analysis with traditional QTL mapping,we successfully mapped the potato freezing tolerance genes to a specific region on Chr07,spanning 1.25 Mb,with a phenotypic contribution rate of 18.81％.In short,current research provides a haplotype-resolved reference genome of the diploid wild potato species S.commersonii and establishes a foundation for further cloning and unraveling the mechanisms underlying cold tolerance in potatoes.

Transitory starch and vacuolar sugars function as highly dynamic pools of instantly accessible metabolites in plant leaf cells. Their metabolic regulation is critical for plant survival. The tonoplast sugar transporters (TSTs), responsible for sugar uptake into vacuoles, regulate cellular sugar partitioning and vacuolar sugar accumulation. However, whether TSTs are involved in leaf transient starch turnover and plant growth is unclear. Here, we found that suppressing StTST3.1 resulted in growth retardation and pale green leaves in potato plants. StTST3.1-silenced plants displayed abnormal chloroplasts and impaired photosynthetic performance. The subcellular localization assay and the oscillation expression patterns revealed that StTST3.1 encoded a tonoplast-localized protein and responded to photoperiod. Moreover, RNA-seq analyses identified that starch synthase (SS2 and SS6) and glucan water, dikinase (GWD), were downregulated in StTST3.1-silenced lines. Correspondingly, the capacity for starch synthesis and degradation was decreased in StTST3.1-silenced lines. Surprisingly, StTST3.1-silenced leaves accumulated exceptionally high levels of maltose but low levels of sucrose and hexose. Additionally, chlorophyll content was reduced in StTST3.1-silenced leaves. Analysis of chlorophyll metabolic pathways found that Non-Yellow Coloring 1 (NYC1)-like (NOL), encoding a chloroplast-localized key enzyme that catalyzes the initial step of chlorophyll b degradation, was upregulated in StTST3.1-silenced leaves. Transient overexpression of StNOL accelerated chlorophyll b degradation in tobacco leaves. Our results indicated that StTST3.1 is involved in transitory starch turnover and chlorophyll metabolism, thereby playing a critical role in normal potato plant growth.

Potato cultivars (Solanum tuberosum L.) are delicate to cold and frost. Low temperatures have a negative impact on potato growth, development and yield. However, genetic detection of frost tolerance loci is currently lacking. Here, we report a BC1 population that was constructed by crossing the diploid cold-resistant wild species S. commersonii with the diploid cold-sensitive wild species S. verrucosum. The frost tolerance of the resulting offspring was determined through four years of natural field frost experiments. Together with bulked segregant analysis (BSA) technology and traditional quantitative trait locus (QTL) mapping, four highly related QTLs were detected on Chr02 and Chr11. Furthermore, we constructed a partial genetic linkage map of Chr02, and two QTLs (QTL1 and QTL2) were detected on Chr02. Four genes located in candidate intervals have been reported to be associated with tolerance to abiotic stress and were significantly differentially expressed among the resistant and sensitive. Taken together, our results also suggest that the frost resistance of plants under variable low-temperature conditions is controlled by different loci.

A multi-parental population is an innovative tool for mapping large numbers of loci and genetic modifications, particularly where they have been used for breeding and pre-breeding in crops. Frost injury is an environmental stress factor that greatly affects the growth, development, production efficiency, and geographical distribution of crops. No reported study has focused on genetic mapping and molecular marker development using diallel populations of potatoes. In this study, 23 successful cross combinations, obtained by a half diallel cross among 16 parents, including eight frost-tolerant advanced breeding lines and eight cultivars, were used to map the genetic loci for frost tolerance and to create a molecular marker-assisted selection (MAS) system. Three candidate regions related to frost tolerance on chromosomes II, V, and IX were mapped by bulked segregant analysis (BSA). Furthermore, six SNP markers associated with frost tolerance from candidate regions were developed and validated. Above all, a MAS system for the frost tolerance screening of early breeding offspring was established. This study highlights the practical advantages of applying diallel populations to broaden and improve frost-tolerant germplasm resources.

Our genomic investigation confirms the mechanism of 2n eggs formation in S. malmeanum and aid in optimizing the use of wild germplasm. Wild potatoes are a valuable source of agronomic traits. However, substantial reproductive barriers limit gene flow into cultivated species. 2n gametes are instrumental in preventing endosperm abortion caused by genetic imbalances in the endosperm. However, little is known about the molecular mechanisms underlying the formation of 2n gametes. Here, the wild species Solanum malmeanum Bitter (2x, 1EBN, endosperm balance number) was used in inter- and intrapoloid crosses with other Solanum species, with viable seeds being produced only when S. malmeanum was used as the female parent to cross the 2EBN Solanum genus and with the likely involvement of 2n gametes. Subsequently, we substantiated the formation of 2n eggs in S. malmeanum using fluorescence in situ hybridization (FISH) and genomic sequencing technology. Additionally, the transmission rate of maternal heterozygous polymorphism sites was assessed from a genomic perspective to analyze the mode of 2n egg formation in S. malmeanum × S. tuberosum and S. malmeanum × S. chacoense crosses; each cross acquired an average of 31.12

Background Karyotype, as a basic characteristic of species, provides valuable information for fundamental theoretical research and germplasm resource innovation. However, traditional karyotyping techniques, including fluorescence in situ hybridization (FISH), are challenging and low in efficiency, especially when karyotyping aneuploid and polyploid plants. The use of low coverage whole-genome resequencing (lcWGR) data for karyotyping was explored, but existing methods are complicated and require control samples. Results In this study, a new protocol for molecular karyotype analysis was provided, which proved to be a simpler, faster, and more accurate method, requiring no control. Notably, our method not only provided the copy number of each chromosome of an individual but also an accurate evaluation of the genomic contribution from its parents. Moreover, we verified the method through FISH and published resequencing data. Conclusions This method is of great significance for species evolution analysis, chromosome engineering, crop improvement, and breeding.

Low temperature is one of the important environmental factors affecting the growth development of potato. In the previous study, arginine decarboxylase gene ADC1, associated with putrescine synthetic pathway enhances potato cold-acclimated resistance. In this research, to further explore the mechanism by which putrescine pathway regulates potato cold-acclimated resistance, a comparative transcriptome was conducted. GO and KEGG enrichment analysis indicated that ABA signaling pathway was significantly enriched in ADC1 transgenic lines (OE) after cold acclimation. The expression of several genes in ABA signaling pathway, such as three PYLs, two SnRK2s and AREB2, was up-regulated. And ABA could improve cold resistance in potato indicated by reduced electrolyte leakage under freezing temperature and enhance putrescine synthetic pathway indicated by increased expression of ADC1 and putrescine accumulation. There are several ABRE binding sites on the ADC1 promoter, and Dual-Luciferase assay showed that AREB/ABF/ABI5 family members especially AREB2, enhanced the transcriptional activity of the ADC1 promoter. In conclusion, putrescine synthesis pathway improves potato cold -acclimated resistance through up-regulating of ABA signaling pathway. In turn, ABA with AREB2 enhances putrescine synthetic pathway. There exists elaborate feedback regulation between putrescine synthetic pathway and ABA pathway to form cold-acclimated tolerance in potato. The excavation of the mechanism underlying cold resistance provides gene resources and theoretical bases for production practice in potato.

Plant viruses impose serious threats on crop production. Artificial miRNAs can mediate specific and effective gene silencing in plants and are widely used in plant gene function studies and to engineer plant viral resistance. To facilitate the design of artificial miRNA genes, we developed a webserver, AMIRdesigner, which can be used to design oligos for artificial miRNA synthesis using wild-type and permutated MIR171 and MIR164 backbones. The artificial miRNA genes designed by AMIRdesigner can be easily assembled into miRNA clusters for multiple target sites. To validate the server functionality, we designed four artificial miRNA genes targeting four conserved regions in the potato leafroll virus genome using AMIRdesigner. These genes were synthesized with the server-designed oligos and further assembled into a quadruple miRNA cluster, which was cloned into an overexpression vector and transformed into potato plants. Small RNA Northern blot and virus inoculation analyses showed that a high level of artificial miRNA expression and good viral resistance were achieved in some of the transgenic lines. These results demonstrate the utility of our webserver AMIRdesigner for engineering crop viral resistance.

The Potato virus Y (PVY) is responsible for huge economic losses for the potato industry worldwide and is the fifth most consequential plant virus globally. The main strategies for virus control are to limit aphid vectors, produce virus-free seed potatoes, and breed virus-resistant varieties. The breeding of PVY-resistant varieties is the safest and most effective method in terms of cost and environmental protection. Ry(chc), a gene that confers extreme resistance to PVY, is from S. chacoense, which is a wild diploid potato species that is widely used in many PVY-resistant breeding projects. In this study, Ry(chc) was fine mapped and successfully cloned from S. chacoense accession 40-3. We demonstrated that Ry(chc) encodes a TIR-NLR protein by stably transforming a diploid susceptible cultivar named AC142 and a tetraploid potato variety named E3. The Ry(chc) conferred extreme resistance to PVYO, PVYN:O and PVYNTN in both of the genotypes. To investigate the genetic events occurring during the evolution of the Ry(chc) locus, we sequenced 160 Ry(chc) homologs from 13 S. chacoense genotypes. Based on the pattern of sequence identities, 160 Ry(chc) homologs were divided into 11 families. In Family 11 including Ry(chc), we found evidence for Type I evolutionary patterns with frequent sequence exchanges, obscured orthologous relationships and high non-synonymous to synonymous substitutions (Ka/Ks), which is consistent with rapid diversification and positive selection in response to rapid changes in the PVY genomes. Furthermore, a functional marker named MG64-17 was developed in this study that indicates the phenotype with 100% accuracy and, therefore, can be used for marker-assisted selection in breeding programs that use S. chacoense as a breeding resource.

为解决微型薯生产过程中,从组培苗到网棚生产的流程繁琐、劳动强度大的问题,设计了一种工作一次可取5株组培苗的吸附式末端执行器.该吸附式末端执行器在PLC的控制下,完成组培盒与穴盘之间株距的变化;由真空发生器产生的真空,使吸嘴将组培苗吸附;在吸附式末端执行器移至穴盘上方后,切断真空,并由推苗装置将组培苗放置在穴盘孔中,完成组培苗的移栽过程.分析并确定吸嘴的关键参数后,通过仿真分析和单因素试验选择了效果较好的吸嘴类型.为明确穴盘孔直径d、株距调整速度v1、吹苗正压p1、苗吸附高度h等因素对移栽效果的影响,以移栽成功率为试验指标进行了正交试验.结果表明:苗吸附高度h对移栽成功率有显著性影响,而穴盘孔直径d、株距调整速度v1、吹苗正压p1没有显著性影响;当d=15 mm、v1=50mrn/s、p1=1 000 Pa、h=45 mm时,组培苗的移栽成功率最高,为87.98％,吸附式末端执行器的移栽效果最好,移栽效率约为2 087株/h,满足设计要求.

: Somatic hybridization is an important way to create new germplasm. Somatic hybrids produced plenty of genetic variation during protoplast regeneration. In this study, to analyze the chromosome composition and variation of potato and eggplant somatic hybrids, rDNAs and telomeric repeats were used as probes for FISH (fluorescence in situ hybridization), combined with GISH (Genomic in situ hybridization). The results showed that rearranged chromosomes and dicentric chromosomes existed in somatic hybrids, and the parts of the rearranged chromosomes was derived from the end-to-end fusion of potato and eggplant chromosomes 2. One centromere of the rearranged dicentric chromosomes was derived from potato and the other was from eggplant. Eggplant 5S rDNA sites were lost in somatic hybrids to homogenize the rDNA of somatic hybrids. The results of this study indicated that the chromosomes were unstable during the somatic hybridization of potato and eggplant, which can easily cause dicentric and chromosomal rearrangements in somatic hybrids. The chromosomes of somatic hybrids tended to be stable through various ways such as chromosome rearrangement, dicentric and rDNA homogenization.

Currently, potato tissue culture plantlets are often cut by mechanical shear in the process of transplanting. However, this method requires the repeated disinfection of cutting tools, which is not conducive to the realisation of mechanised operations. To solve this problem, a laser cutting method of potato tissue culture plantlets was explored based on our newly developed incubator in this study. The laser cutting experiments of the potato tissue culture plantlets were performed by two methods (row-by-row cutting and column-by-column cutting). The experimental results indicated that the efficiency of row-by-row cutting of potato tissue culture plantlets was higher than that of column-by-column cutting. When the optical output power of CO 2 laser was 70 W and the cutting speed was 36 mm/s, it only took 8.3 s to complete the cutting of the whole box of tissue culture plantlets. In addition, the biological activity experiments of potato tissue culture plantlets indicated that all the growth indices (including survival rate, plant height, internode number, internode length, stem diameter, root length, and rootless fresh weight) of tissue culture plantlets through row-by-row cutting were superior to those through mechanical cutting. Our experiment shows that contactless cutting of tissue culture plantlets, high cutting efficiency, and no pollution can be achieved through the new culture incubator in combination with laser cutting technology. Our findings provide reference for the development of novel potato cutting transplantation equipment.

马铃薯疮痂病是由致病链霉菌引起的土传性和种传性病害,在世界各地的马铃薯种植区广泛发生.该病主要破坏马铃薯薯块表皮,降低马铃薯的经济价值.目前在中国马铃薯疮痂病抗病品种缺乏的情况下,药剂处理还是田间防治该病的主要措施.试验采用五氯硝基苯和噻唑锌2种药剂分别处理带疮痂病病原的蛭石,以未处理的蛭石为对照.结果表明,对感病的'华薯3号'品种,2019年上半年五氯硝基苯对疮痂病的防效为42.73％,噻唑锌对疮痂病的防效为31.41％.2019年下半年五氯硝基苯防效为57.48％,噻唑锌防效为87.16％.目前的生产中尚不具有高抗疮痂病的马铃薯品种,抗性资源试验中,将健康的马铃薯资源材料种植于带疮痂病的蛭石中,结果表明,在试验的华薯系列品种中,'华薯5号'和'华薯11号'相较其他品种,疮痂病抗性较好;试验具有野生种Solanum chacoense血缘的材料中,CH524-8和M6对疮痂病具有较高的抗性.

马铃薯种植过程中,覆膜栽培早已成为常见的种植方式,对于地膜覆盖的研究,一直是科研工作者的研究重点.为研究不同颜色地膜对马铃薯生长发育及产量的影响,采用'中薯5号'为试验材料,设置白色地膜、黑色地膜、黑白双色地膜处理,未覆膜为对照处理,对其膜下15 cm处土壤温度、出苗时间、农艺性状及收获产量进行测量.结果表明,不同颜色地膜处理对马铃薯出苗期有极显著影响,白色地膜处理出苗时间最短,相较于未覆膜提早5 d,覆盖黑色地膜较未覆膜延迟出苗4 d,黑白双色膜与未覆膜处理在出苗天数上无显著差异.在产量上,覆盖白色地膜产量最高,产量为2594 kg/667m2,较未覆膜处理增产24.35％.因此,在中原二季作区春播马铃薯生产中,建议采用白色地膜覆盖,可有效提早马铃薯出苗时间,提高产量与商品薯率,进而提高经济效益.

通过田间小区试验评价了6个不同处理对蛭石栽培的微型马铃薯疮痂病的防效,并采用16S核糖体基因高通量测序技术研究了蛭石中细菌群落结构的变化.试验结果显示,棉隆+青霉菌34107处理对疮痂病防效最好(93.43％),显著高于对照药剂中生菌素处理(65.10％);而且商品薯的数量和经济效益也最高,分别达到348.3万个/hm2和35.70万元/hm2.蛭石中细菌相对丰度均以变形菌门(Proteobacteria)、放线菌门(Actinobac-teria)和拟杆菌门(Bacteroidetes)最高,但不同处理之间丰度差异较大.除青霉菌34107处理外,其余处理细菌多样性指数均有不同程度的下降,但棉隆+青霉菌34107处理较中生菌素处理高,且显著高于棉隆处理(P<0.05).统计分析结果显示,总共185个属的丰度发生显著变化(P<0.05),其中92个属(49.7％)为5个处理共有.棉隆和青霉菌34107处理发生显著变化属的数量最多(112个),而棉隆+青霉菌34107处理最少,仅30个属上调.在青霉菌34107和棉隆+青霉菌34107处理中,有益菌假单胞杆菌(Pseudomonas)数量显著增加,说明青霉菌34107处理,尤其是与棉隆协同使用,能有效促进蛭石中有益菌繁殖.相关性分析结果显示,蛭石中链霉菌丰度与55个属细菌呈显著正相关(P<0.05,r>0.6),包括中慢生根瘤菌(Mesorhizobium)、Solirubrobacter、包层不黏柄菌(Asticcacaulis)等,而与Dyadobacter、Pedobacter、Paenarthrobacter等8个属丰度呈显著负相关(P<0.05,r<-0.6).研究结果表明,以棉隆消毒联合青霉菌34107处理对微型薯疮痂病防效最好,同时促进了蛭石中细菌多样性和有益菌的增殖.此外,还发现链霉菌的数量与土壤多种细菌密切相关.

近年来随着我国马铃薯脱毒技术日益成熟,马铃薯微型薯(简称"微型薯")的产量逐年增加,但生产成本的急剧上升严重制约了优质微型薯的推广和应用.本文对微型薯生产的农艺过程进行了总结,简述茎尖脱毒、试管培养、组培继代、介质培养、种薯大田扩繁的基本农艺过程;分析了微型薯每个生产过程中所需要的机械化生产关键技术,包括组培继代过程中所需的机器视觉系统以及组培苗的抓取和切割技术、介质栽培过程中所需的温室生长条件控制系统和智能化环境监控系统、微型薯播种过程中所需的微型薯播种技术等;对国内外微型薯生产相关机械化装备的研究现状进行了总结,包括组培继代、介质培养、微型薯播种等过程中所需的机械化装备;提出了加强农机农艺融合技术的研究、加速基础共性技术机制的研究、争取政策与资金的支持、加快我国种薯产业及机械化的发展等意见和建议,以推进微型薯生产技术与装备向自动化、智能化方面发展,从而提高优质微型薯的应用量,促进我国马铃薯产业的发展.