Pseudomonas frederiksbergensis FC-17 shows prominent biological control for potato wilt disease caused by Ralstonia solanacearum. It remains unknown whether the biocontrol strain can effectively colonize rhizosphere soil and how it affects the bacterial community. Therefore, we used qPCR to track the abundance changes of FC-17 in the potato rhizosphere within 30 days after pathogen inoculation. The findings showed that applying bio-organic fertilizer, produced by secondary solid fermentation of organic fertilizer and FC-17, effectively improved disease control but did not enhance FC-17 colonization. 16S rRNA gene amplicon sequencing indicated that disease suppression was primarily attributed to the alterations in bacterial community composition, rather than the competitiveness of the inoculated FC-17 strain. Under pathogen pressure, bio-organic fertilizer treatment enriched specific bacterial genera, including Sphingomonas, Sphingobium, Lysobacter, and Isoptericola. Among these, Lysobacter and Sphingomonas were negatively correlated with the disease index, suggesting their potential role in suppressing potato bacterial wilt. This study elucidates a microbiome-mediated biocontrol mechanism, highlighting that optimizing the resident microbial community is a crucial strategy for sustainable disease management. Our results provide a theoretical foundation for combining P. frederiksbergensis with organic fertilizer to control potato bacterial wilt.

Sustainable management of flue-cured tobacco requires a careful balance among productivity, chemical composition, and soil ecological function, which are often disrupted by excessive chemical fertilization. This study aimed to elucidate how microbial fertilization regulates plant performance, chemical coordination, and rhizosphere microbial structure under field conditions. A two-year factorial field experiment was conducted in Sichuan, China, using a Bacillus-based plant growth-promoting microorganism (PGPM) and a commercial microbial consortium (Xi⋅Weifeng), applied individually or in combination at gradient doses. Agronomic traits, cured-leaf chemical composition, secondary metabolites, and rhizosphere bacterial communities were comprehensively analyzed using multivariate statistics, network correlation analysis, and structural equation modeling (SEM). Moderate PGPM application (27 kg⋅ha–1) significantly increased plant height (8.6%), internode length (15.3%), and leaf width (7.8%) at the vigorous growth stage. Co-application further enhanced leaf expansion (9.7%) and improved chemical coordination, maintaining optimal sugar/nicotine (8–12) and N/nicotine (0.7–1.0) ratios. Chlorogenic acid (18.8 mg⋅g–1) and neochlorogenic acid (2.7 mg⋅g–1) were markedly elevated under the A27B54 treatment. Rhizosphere bacterial diversity peaked under co-application, with Bacillus, Rhizobiales, and Sphingomonas emerging as key taxa positively associated with both metabolic and agronomic improvements. SEM demonstrated that fertilization effects on leaf quality were mediated indirectly through microbial community restructuring and metabolite modulation. Microbial fertilizer co-application enhances tobacco performance by promoting rhizosphere microbial diversity and functional coordination, which in turn improves metabolic balance and nutrient-use efficiency. These findings highlight a soil microbiome-mediated pathway linking fertilization strategy to crop physiological and chemical responses, providing mechanistic insights for sustainable fertilization management.

King grass is a fast-growing C4 perennial with high biomass potential, yet its productivity is limited by cold stress. WRKY transcription factors (TFs) regulate abiotic stress responses, but their roles in king grass cold adaptation remain unclear. WRKY TFs were identified genome-wide using BLASTP and HMMER, followed by phylogenetic classification, transcriptome profiling, promoter cis-element analysis, weighted gene co-expression network analysis (WGCNA), molecular docking, and yeast heterologous expression assays. Sixty-two PsiWRKY genes were identified and classified into three groups. Time-series transcriptome analysis across nine cold-stress time points revealed four expression patterns, with 29 genes significantly induced (> 2-fold), mainly during late acclimation (48–72 h). qRT-PCR confirmed RNA-seq trends (R² = 0.742). Functional enrichment and WGCNA analyses indicated that cold-responsive PsiWRKYs coordinate abscisic acid-gibberellin antagonism and sugar metabolism. Molecular docking predicted interactions between PsiWRKY proteins and Calvin cycle enzymes, with PsiWRKY16 and PsiWRKY55 showing the highest structural confidence (pTM > 0.75). Network analysis identified PsiWRKY16 and PsiWRKY50 as hub regulators linking GA signaling genes (GID1/DELLA) with sugar metabolism enzymes such as GAPDH and PRK. Yeast assays quantitatively confirmed enhanced cold tolerance, as heterologous expression of PsiWRKY16 reduced doubling time by 0.56 h and increased area under the curve and carrying capacity by 26.20 and 3.39, respectively, while PsiWRKY50 increased these values by 14.45 and 1.43. Promoter analysis showed enrichment of ABRE and DRE elements (p = 0.00061), and integrative target prediction identified 193 genes co-regulated by WRKY and CBF pathways, supporting ABA-CBF signaling convergence. PsiWRKYs exhibit subgroup-specific and time-resolved responses to cold stress. PsiWRKY16, PsiWRKY50, and PsiWRKY55 are implicated in coordinating hormonal signaling and metabolic reprogramming, providing candidate targets for cold-tolerant breeding in king grass.

Potatoes serve as a globally significant staple and vegetable crop, playing a pivotal role in ensuring food security and providing essential nutrients. However, potatoes are susceptible to a variety of pests and diseases, among which bacterial wilt caused by Ralstonia solanacearum stands out as one of the most severe bacterial diseases, posing a significant threat to the global potato industry. Currently, although there have been numerous studies on potato bacterial wilt, there is still a need for further exploration in terms of integrated management and innovative prevention and control strategies. This review comprehensively sorts out existing research on the classification, pathogenic mechanisms, and control measures of potato bacterial wilt, with a particular focus on the latest advancements in the fields of biological control and genetic engineering. Compared with existing literature, this review delves deeply into analyzing the inhibitory effects of various beneficial microorganisms and their synergistic mechanisms in biological control on bacterial wilt, and uncovers the unique potential and action pathways of genetic engineering technology in breeding potato varieties resistant to bacterial wilt. By integrating these cutting-edge research findings, this review aims to provide a set of innovative and feasible integrated methods for the scientific and efficient management of bacterial wilt, thereby promoting the healthy and sustainable development of the potato industry.

Salt stress has become one of the major abiotic stress factors limiting sustainable crop production worldwide, and potato, as the fourth largest food crop globally, is particularly severely affected by saline and other environmental stresses in terms of its growth, development, yield, and quality. StBIN2 belongs to the GSK3 family of proteins, and numerous studies have confirmed that GSK3 family members widely regulate diverse abiotic stress responses and developmental processes in plants. However, the specific function and underlying mechanism of StBIN2 in the salt stress response of potato remain unclear. In this study, using the potato cultivar ‘Chuanyu 10’ as experimental material, we successfully isolated and cloned the StBIN2 gene and systematically investigated its biological function under salt stress. Subcellular localization analysis revealed that the StBIN2 protein is localized in the nucleus. Tissue-specific expression pattern analysis showed that StBIN2 transcript levels were significantly higher in leaves and tuber tissues than in other tissues. Under 200 mM NaCl salt stress treatment, StBIN2-overexpressing potato lines exhibited enhanced salt stress tolerance compared with WT plants, whereas gene-silenced lines displayed a hypersensitive phenotype to salt stress. Physiological parameter measurements demonstrated that the activities of superoxide dismutase (SOD) and catalase (CAT) in overexpressing transgenic plants were significantly upregulated relative to those in the WT, whereas the levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) were markedly reduced. Collectively, these experimental results confirm that StBIN2 significantly enhances salt tolerance in transgenic potato, indicating that potato StBIN2 positively participates in the physiological regulation of salt stress. This work lays an important foundation for further elucidation of the functional mechanism of StBIN2 within the plant abiotic stress response network.

BACKGROUND:The phytoene desaturase gene is a classical visual marker for validating CRISPR/Cas9 genome editing in plants, as its loss of function produces a readily scorable albino phenotype. While the biochemical basis of pigment loss is well established, it remains unclear whether pds knockout elicits transcriptomic changes extending beyond carotenoid biosynthesis. Resolving this question is essential for correctly interpreting pds-based editing outcomes and for assessing the robustness of phenotype-only screening approaches. METHODS:A CRISPR/Cas9 editing platform targeting pds was established in diploid potato. Albino, non-albino edited, and wild-type tissues were subjected to RNA-seq profiling. Differential expression, functional enrichment, and weighted gene co-expression network analysis were integrated to resolve phenotype-associated transcriptional modules, and hierarchical regulatory layers underlying albinism. RESULTS:CRISPR/Cas9-mediated disruption of pds in potato-generated stable albino phenotypes and revealed extensive transcriptomic reprogramming that was not limited to pigment loss. Albino tissues exhibited more than 9700 differentially expressed genes relative to both wild-type and non-albino edited tissues, whereas non-albino edits showed substantially fewer changes. Functional enrichment demonstrated pervasive suppression of photosynthesis and carbon metabolism alongside activation of secondary metabolism, stress responses, hormone signaling, and cell wall remodeling. WGCNA and cross-validation resolved these changes into distinct, phenotype-associated regulatory layers: MEorangered4 captured coordinated repression of starch and sucrose metabolism (r = -0.998), MEdarkgreen marked albino-linked activation of secondary metabolism and barrier biogenesis (r = 0.855; overlap with Albino Core set, OR = 23.65), while MEblack and MEgrey60 reflected downregulation of stress signaling, proteostasis, and hormone-integrative control and were enriched in transgenic-background-associated gene sets. CONCLUSIONS:pds knockout in potato is accompanied by broad transcriptomic changes beyond pigment biosynthesis, suggesting that albinism involves coordinated regulatory and metabolic adjustment under plastid dysfunction rather than pigment loss alone. These results refine the use of pds as a visual editing marker and provide a framework for linking localized genome edits to coordinated network-level transcriptional responses in plants.

Potato is a globally significant food and economic crop, playing a crucial strategic role in ensuring global food security and promoting economic development. The Snakin/GASA (gibberellic acid-stimulated Arabidopsis) family, a group of plant antimicrobial peptides regulated by hormones, play key roles in plant growth and development through hormone signal transduction. Previous studies have shown that overexpression of StSN2 significantly increases the tuber numbers and the proportion of large tubers, suggesting that StSN2 is a critical regulator of tuber formation, although its precise mechanism remains unclear. In this study,researchers utilized CRISPR/Cas9 technology to regulate the expression level of StSN2 in potatoes, and delved into the function of StSN2 in potato tuber formation. The research results show that deletion of the StSN2 gene led to a delay of about 14 days in the formation of potato stolons, and a decrease in yield by 20-30%. Bioinformatics analysis of the StSN2 promoter identified multiple cis-regulatory elements, and exogenous ABA and GA treatments confirmed that StSN2 responds strongly to ABA induction. Further analysis of key gene expression and enzyme activities during tuber development demonstrated that StSN2 enhances the ABA signaling pathway by upregulating components such as StPYL1, StSnRK2.2/2.3/2.6, and StABI5, thereby promoting tuber formation. In conclusion, this study integrates genetic, molecular, and physiological approaches to elucidate the regulatory role of StSN2 in potato tuber formation. The findings enrich our understanding of the molecular mechanisms underlying tuber development and provide a theoretical foundation for improving potato yields and stability through molecular design.

IntroductionCold acclimatization in tropical region-originated plants involves complex gene expression reprogramming to adapt to fluctuating temperatures. However, the molecular mechanisms and gene networks regulating cold tolerance in king grass remain largely unknown.MethodsTo address this, we established a full-length reference transcriptome of king grass to enhance assembly quality and performed multiple time-point transcriptomic analyses following cold treatment at 4°C. Differentially expressed genes (DEGs) and transcription factors (TFs) involved in cold stress response were identified and analyzed through clustering and co-expression network analysis.ResultsA total of 13,056 DEGs were identified and classified into nine clusters via k-means analysis. The cold response exhibited three distinct phases: early (before 3 h), middle (6–24 h), and late (48–72 h). Early-responsive genes were enriched in glycolipid metabolism and photosynthesis, middle-stage genes in carbohydrate metabolism, and late-stage genes in cold stress, osmotic stress, and endogenous stimuli responses. Key regulators of the ICE-CBF-COR signaling module, including 13 positive and negative regulators, were identified. The co-expression network further revealed mutual regulatory interactions within this module, highlighting its role in cold stress adaptation.DiscussionOur findings provide insights into the cold tolerance mechanisms of king grass, offering a genetic basis for modifying cold stress regulators. This research contributes to the broader understanding of low-temperature adaptive mechanisms in tropical plants and supports future breeding strategies for improved cold tolerance.

IntroductionPlant root-associated microbiomes play an important role in plant health, yet their responses to bacterial wilt remain unclear poorly understood.MethodsThis study investigated spatial variations in microbiome and metabolome composition across three root-associated niches—root-surrounding soil, rhizosphere, and endosphere—of healthy and Ralstonia solanacearum-infected potato plants. A total of 36 samples were analyzed, with microbial diversity assessed by full-length 16S rRNA and ITS sequencing, and metabolic profiles characterized using LC-QTOF-MS.ResultsAlpha diversity analysis revealed that bacterial diversity in healthy plants was consistently higher than in diseased plants, progressively increasing from the root-surrounding soil to the rhizosphere, and most notably in the endosphere, where the Shannon index declined from 5.3 (healthy) to 1.2 (diseased). In contrast, fungal diversity was lower in diseased plants in the root-surrounding soil and rhizosphere, but significantly elevated in the endosphere, suggesting niche-specific microbial responses to pathogen stress. Beta diversity confirmed significant microbiome restructuring under pathogen stress (R² > 0.5, p = 0.001). Taxonomic analysis showed over 98% dominance of Proteobacteria in the diseased endosphere, where Burkholderia, Pseudomonas, and Massilia enriched in healthy plants were significantly reduced. R. solanacearum infection promotes the enrichment of Fusarium species in both the rhizosphere and endosphere. Metabolomic analysis revealed extensive pathogen-induced metabolic reprogramming, with 299 upregulated and 483 downregulated metabolites in the diseased endosphere, including antimicrobial metabolites such as verruculogen and aurachin A. Network analysis identified XTP as a central metabolite regulating microbial interactions, whereas antimicrobial metabolites exhibited targeted pathogen suppression. O2PLS analysis revealed that pathogen-induced antimicrobial metabolites (e.g., Gentamicin X2, Glutathionylspermine) were associated with Clostridia and Ketobacter in diseased plants, while nucleotide-related compounds (e.g., XTP) correlated with Rhodomicrobium and others, indicating infection-driven microbial adaptation and metabolic restructuring.DiscussionThese findings provide insights into pathogen-driven disruptions in root microbiomes and suggest potential microbiome engineering strategies for bacterial wilt management.

Tropical forage crops vary widely in biochemical composition, resulting in inconsistent silage quality. Understanding how plant traits shape microbial and metabolic networks during ensiling is crucial for optimizing fermentation outcomes. Eight tropical forages—Sorghum bicolor (sweet sorghum), Sorghum × drummondii (sorghum–Sudangrass hybrid), Sorghum sudanense (Sudangrass), Pennisetum giganteum (giant Napier grass), Pennisetum purpureum cv. Purple (purple elephant grass), Pennisetum sinese (king grass), Leymus chinensis (sheep grass), and Zea mexicana (Mexican teosinte)—were ensiled under uniform conditions. Fermentation quality, bacterial and fungal communities (16S rRNA and ITS sequencing), and metabolite profiles (untargeted liquid chromatography–mass spectrometry, LC-MS) were analyzed after 60 days. Sweet sorghum and giant Napier grass showed optimal fermentation, with high lactic acid levels (111.2 g/kg and 99.4 g/kg, respectively), low NH4+-N (2.4 g/kg and 3.1 g/kg), and dominant Lactiplantibacillus plantarum. In contrast, sheep grass and Mexican teosinte exhibited poor fermentation, with high NH4+-N (6.7 and 6.1 g/kg) and Clostridium dominance. Fungal communities were dominated by Kazachstania humilis (>95%), while spoilage-associated genera such as Cladosporium, Fusarium, and Termitomyces proliferated in poorly fermented silages. Metabolomic analysis identified 15,827 features, with >3000 significantly differential metabolites between silages. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment revealed divergence in flavonoid biosynthesis, lipid metabolism, and amino acid pathways. In the sweet sorghum vs. sheep grass comparison, oxidative stress markers ((±) 9-HODE, Agrimonolide) were elevated in sheep grass, while sweet sorghum accumulated antioxidants like Vitamin D3. Giant Napier grass exhibited higher levels of antimicrobial flavonoids (e.g., Apigenin) than king grass, despite both being dominated by lactic acid bacteria. Sorghum–Sudangrass hybrid silage showed enrichment of lignan and flavonoid derivatives, while Mexican teosinte accumulated hormone-like compounds (Gibberellin A53, Pterostilbene), suggesting microbial dysbiosis. These findings indicate that silage fermentation outcomes are primarily driven by forage-intrinsic traits. A “forage–microbiota–metabolite” framework was proposed to explain how plant-specific properties regulate microbial assembly and metabolic output. These insights can guide forage selection and development of precision inoculant for high-quality tropical silage.

The microbiota in forage silage plays a pivotal role in determining the fermentation quality. Identifying effective microbial additives is essential to help forage producers refine their search for functional inoculants and to support farmers in adopting them for practical ensiling. This study investigated microbial and metabolomic dynamics in king grass silages treated with six commercial inoculants dominated by Enterococcus faecium-like species, Bacillus velezensis, and Lactobacillus paraplantarum. The fermentation characteristics, viable microbial diversity, and metabolite profiles were compared between treated and untreated silages using 16S rDNA sequencing and metabolic profiling via LC-QTOF-MS, integrated with multi-omics correlation analyses. Additive-treated silages showed improved fermentation quality, simplified bacterial correlation networks, and distinct microbial successions and interactions. A total of 1523 metabolites were detected, with 56–84 significantly altered in each treated group compared to the control. Metabolites with antimicrobial, antioxidant, and cholesterol-lowering activities were more abundant in treated silages, especially organic acids, amino acids, and short-chain fatty acids. Inoculants distinctly influenced amino acid, energy, nucleotide, and vitamin metabolism during ensiling. This study advances our understanding of how commercial microbial additives reshape the bacterial community structure and function in silages and highlights promising lactic acid bacteria species contributing to silage quality through the production of bio-functional metabolites.

Late blight caused by Phytophthora infestans seriously threatens world’s potato production. Understanding the responsive mechanism of potato to P. infestans infection and exploring key regulators would be advantageous for improving the late blight resistance. Here, we firstly assessed the late blight resistance of 10 potato cultivars collected from Liangshan Yi Autonomous Prefecture and found that Chuan Liang Shu (CLS) is highly resistant, while Bu Wu Yu (BWY) is extremely susceptible. Comparative transcriptomics further revealed distinct mechanisms of CLS and BWY in response to P. infestans infection, in which CLS activates defense pathways rapidly, while BWY prioritizes energy towards growth and development pathways. Specifically, the up-regulated genes in CLS were largely enriched in oxidation-reduction process and SA-related pathways, resulting in activated ROS-scavenging systems and SA signaling. Clustering analysis for the expression patterns of transcription factors (TFs) demonstrates that the WRKY family members were significantly enriched in a cluster that is specifically induced in CLS after P. infestans infection. Silencing StWRKY26, one of the four WRKYs with higher induction levels, significantly compromise the intrinsic resistance against P. infestans in CLS. Our study enriches the knowledge of transcriptional responses of potato under P. infestans infection and provide candidate genes for breeding potato cultivars with strong late blight resistance.

Bacterial wilt, caused by Ralstonia solanacearum (Rs), often presents as a symptomless latent infection where plants test positive for Rs but exhibit no visible symptoms. While latent infection is associated with pathogen exposure, the role of rhizosphere microorganisms in plant resistance remains unclear. This study aimed to investigate whether latently infected potato plants can recruit beneficial microbiomes to mitigate Rs infection. Two potato cultivars, H15 (high susceptibility) and Q9 (low susceptibility), were tested under high pathogen pressure. Full-length 16S rRNA sequencing and microbial network analyses were conducted on rhizosphere samples to assays microbiome responses. Plate inhibition assays and greenhouse inoculation trials were used to screen and validate potential beneficial bacteria from latently infected samples. Resistance to infection differed significantly between the two cultivars, with 86.67

Drought is a negative agronomic effect that can lead to an increase in reactive oxygen species (ROS) levels. Excessive drought can severely alter cell membrane fluidity and permeability, significantly reducing cell viability. The Gibberellic acid-stimulated Arabidopsis (Snakin/GASA) gene family has an important role as antioxidants in inhibiting the accumulation of ROS and improving crop drought resistance. However, the regulatory mechanism of potato StSnakin-2 (StSN2) in response to drought, along with how StSN2 expression is regulated, is not well understood. In this study, we found that StSN2 was induced by drought. Overexpression of StSN2 significantly increased drought tolerance, whereas silencing StSN2 increased sensitivity to drought. Overexpression of StSN2 resulted in higher antioxidant enzyme (superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)) activity, and lowered hydrogen peroxide (H2O2) and malondialdehyde (MDA) accumulation during drought stress. Also, overexpression of StSN2 increased the relative water content (RWC) of leaves and reduced the water loss in leaves. We screened the upstream regulatory protein translation-controlled tumor protein (StTCTP) of StSN2 through DNA pull-down combined with mass spectrometry. Yeast one-hybrid (YIH), electrophoretic mobility shift assay (EMSA), and luciferase reporting assay (LUC) indicated that StTCTP binds the StSN2 promoter. Like StSN2, StTCTP was highly expressed in response to drought. Overexpression of StTCTP increased the photosynthetic rate and CAT enzyme activity, and lowered H2O2 and MDA accumulation during drought. Meanwhile, overexpression of StTCTP increased leaf RWC and reduced water loss. Our research strongly suggested that StSN2 effectively cleared ROS and significantly boosted the drought resistance of potatoes. Furthermore, as a transcriptional activator of StSN2, StTCTP, much like StSN2, also enhanced the potato's drought tolerance. The results provided a foundation for the further study of StSN2 regulatory mechanisms under drought stress.

This study isolated soluble dietary fiber from Tartary buckwheat dehulled seeds (TBSDF) and systematically characterized its physicochemical properties, structural features, bioactivities, and modulatory effects on gut microbiota. Structural analysis revealed TBSDF as a neutral, highly branched heteropolysaccharide with a (1 -> 4)-alpha-D-glucan backbone, primarily composed of glucose, galactose, xylose, galacturonic acid, and arabinose (molar ratio 0.795:0.063:0.057:0.046:0.038), with a predominant low-molecular-weight fraction (6.084 kDa) and high thermal stability. TBSDF exhibited excellent hydration properties, including water solubility (73.26 g/ 100 g), water-holding capacity (6.62 g/g), swelling capacity (3.13 mL/g), and oil-holding capacity (38.01 g/g). It also exhibited strong adsorption capacities for glucose (7.70 f 0.91 mmol/L), sodium cholate (10.14 f 0.26 mg/ g), and cholesterol (2323.01 f 1.73 mg/g at pH 2.0 and 114.94 f 0.86 mg/g at pH 7.0). Dose-dependent antioxidant activity was observed against DPPH, ABTS, and hydroxyl radicals. In vitro fecal fermentation showed TBSDF enriched beneficial bacteria (Megasphaera, Allisonella, Lachnoclostridium, Roseburia, and Succinivibrio), suppressed pathogens (Escherichia-Shigella), and increased the concentrations of short-chain fatty acids (SCFAs), particularly isobutyrate and valerate. PICRUSt analysis linked TBSDF-induced microbial shifts to enhanced carbohydrate, amino acid, energy, and lipid metabolism. These findings underscore TBSDF's potential prebiotic properties and provide a foundation for developing Tartary buckwheat-based functional foods targeting gut health.

Potato (Solanum tuberosum L.) is one of the most economically significant crops globally. Nevertheless, potato cultivation is becoming increasingly susceptible to a multitude of diseases, including bacterial wilt, which is caused by Ralstonia solanacearum. To identify the GRF gene family in potatoes and to examine their expression profiles in response to hormones and R. solanacearum infection. A comprehensive genome-wide analysis was conducted to identify the GRF gene family in the potato genome. A total of 13 GRF genes were identified from the latest potato genome, including five StGRFs belonging to the ɛ group and eight of the non-ɛ group. The transcriptional responses of the StGRFs to two biotic stress-related phytohormones (SA and MeJA) were defined, as well as the response to infection with R. solanacearum in a bacterial wilt-sensitive cultivar, S. tuberosum ‘Qingshu 9’. Many StGRF genes exhibited high induction levels in response to R. solanacearum infection and SA treatment while displaying a marked decline in expression in the presence of MeJA. Furthermore, protein interaction network analysis revealed that the StGRF proteins interact with several candidate target proteins, indicating that GRF proteins are ubiquitous regulators in potatoes. However, the associations between two type III effectors (T3Es) RipAC/RipH2 from R. solanacearum isolates and StGRF7 were not detectable in a yeast two-hybrid assay. This study provides comprehensive information on the GRF gene family and lays a foundation for further research on the molecular mechanism of potato biotic stress adaptation.

ABSTRACT Over-application of chemical fertilizers and continuous cropping obstacles seriously restrict the sustainable development of tobacco production. Localized fertilization of beneficial microbes has potential advantages in achieving higher productivity, but the underlying biological mechanisms of interactions between rhizospheric microorganisms and the related metabolic cycle remain poorly characterized. Here, an integrative analysis of microbiomes with non-targeted metabolomics was performed on 30 soil samples of rhizosphere, root surrounding, and bulk soils from flue‐cured tobacco under continuous and non-continuous monocropping systems. The analysis was conducted using UPLC-MS/MS platforms and high-throughput amplicon sequencing targeting the bacterial 16S rRNA gene and fungal ITS gene. The microbial inoculant consisted of Bacillus subtilis , B. velezensis, and B. licheniformis at the ratio of 1:1:1 in effective microbial counts, improved the cured leaf yield and disease resistance of tobacco, and enhanced nicotine and nitrogen contents of tobacco leaves. The bacterial taxa Rhizobium , Pseudomonas , Sphingomonadaceae , and Burkholderiaceae of the phylum Proteobacteria accumulated in high relative abundance and were identified as biomarkers following the application of the microbial inoculant. Under continuous monocropping, metabolomics demonstrated that the application of the microbial inoculant significantly affected the soil metabolite spectrum, and the differential metabolites were significantly enriched to the synthesis and degradation of nicotine (nicotinate and nicotinamide metabolism and biosynthesis of alkaloids derived from nicotinic acid). In addition, microbes were closely related to the accumulation of metabolites through correlation analysis. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments. IMPORTANCE This study elaborated on how the microbial fertilizer significantly changed overall community structures and metabolite spectrum of rhizospheric microbes, which provide insights into the process of rhizosphere microbial remolding in response to continuous monocropping. we verified the hypothesis that the application of the microbial inoculant in continuous cropping would lead to the selection of distinct microbiota communities by establishing models to correlate biomarkers. Through correlation analysis of the microbiome and metabolome, we proved that rhizospheric microbes were closely related to the accumulation of metabolites, including the synthesis and degradation of nicotine. The interactions between plant roots and rhizospheric microorganisms provide valuable information for understanding how these beneficial microbes affect complex biological processes and the adaption capacity of plants to environments.

[目的]进一步明确烟草连作障碍发生机理,探索烟草短期连作与根际微生物结构和根际代谢物之间的关系.[方法]采用Illumina高通量测序技术和超高效液相色谱串联四级杆飞行时间质谱技术,分析短期连作与未连作植烟根际土壤微生物组和代谢组多样性.[结果]根际细菌菌群多样性在不同品种间、连作与未连作组间均无显著差异,短期连作对根际细菌菌群结构和多样性影响不显著,但短期连作土壤中根际真菌丰度和均匀度显著降低,未连作根际真菌多样性显著高于短期连作根际真菌多样性.甘蓝油壶菌(Olpidium brassicae)、木贼镰刀菌(Fusarium equiseti)丰度在短期连作根际中显著增高,细长被孢霉菌(Moriierella elonga-ta)丰度显著降低.LEfSe分析发现镰刀菌属(Fusarium)真菌为短期连作根际土壤中的标志物微生物.代谢组分析发现,有机氮化合物、鞘脂类、萜类、类固醇及其衍生物为短期连作与未连作植烟根际土壤间的显著差异代谢物.其中,游离氨基酸和小檗碱、茄定碱、酒糟碱等生物碱类物质在短期连作根际土壤中显著富集,表明短期连作过程中可能已经产生真菌感染和自毒效应.[结论]本研究初步解析了烟草短期连作下根际微生物和代谢物的相互关系,虽然短期连作对根际细菌群落的影响较小,但根际次生代谢物产生的化感作用能够快速且显著改变根际真菌菌群结构,导致致病真菌的快速繁殖.

Background/ObjectiveSilage characteristics of grass materials directly affect their silage qualities. To expand the source of silage raw materials and develop mixed silages underlined by exploring the positive interactions between forage grasses and legumes, three gramineous grasses, Napier grass (Pennisetum purpureum), king grass (Pennisetum sinese), and forage maize (Zea mays) were separately mixed ensiled with a combination of four forage legumes including Medicago sativa, Vicia villosa, Vicia sativa, and Trifolium repens.MethodsThe chemical composition and fermentation quality of the mixed silages were analyzed and compared with those of the sole silages of these three grasses, as well as the diversity of microbial communities, through the 16S/ITS full-length sequencing.ResultsThe results showed that the inclusion of forage legumes could somewhat improve the fermentation quality, as indicated by significantly (p < 0.05) higher crude protein and lactic acid contents while lower neutral detergent fiber, acid detergent fiber contents and pH values, compared with the sole silages. Among the three types of mixed silages, the mixed king grass had the highest dry matter and crude protein content as well as lowest neutral detergent fiber and acid detergent fiber content. Meanwhile, the bacterial and fungal communities in the mixed silages were influenced by increased the relative abundance of lactic acid bacteria, which inhibited the proliferation of undesirable bacteria, such as Hafnia alvei, Enterobacter cloacae, and Serratia proteamaculanss. Co-occurrence networks identified 32 nodes with 164 positive and 18 negative correlations in bacteria and 80 nodes with two negative and 76 positive correlations in fungi during fermentation.ConclusionInclusion of forage legume to grasses can improve the fermentation quality and optimize the structure of microbial community, which appears to be a feasible strategy to enhance the forage resource utilization.

This study aimed to investigate the mechanism of Na+/Ca2+-induced soy hull polysaccharide (SHP) migration in the mucus layer. The viscosity, potential, microstructure, SHP migration, and metabolite migration were analyzed. The results showed that Na+ had little effect on the viscosity of polysaccharides, while Ca2+ increased the viscosity of polysaccharides. Na+ and Ca2+ promoted the migration of SHP particles by reducing the zeta potential, while they decreased the migration of SHP chyle particles by increasing the aggregation. SHP was fermented by gut microbiota to produce a large number of short-chain fatty acids (SCFAs). Compared with Ca2+, Na+ increased the migration of total SCFAs in the mucus layer. The high-Na+/Ca2+ mucus internal environment had a specific effect on the transport of nutrients in the intestine.