Sweetpotato is a typical "potassium(K+)-favoring" crop, and K+ deficiency can lead to slow growth, reduced photosynthetic capacity, and lower yield. Genome-wide association study (GWAS) has been widely used in the identification of plant resistance genes; however, there are limited reports on the discovery of low K+ tolerance genes in sweetpotato. In this study, we conducted a GWAS involving 213 sweetpotato cultivars and identified that IbHSP18.0 was significantly associated with low K+ tolerance. We cloned IbHSP18.0, constructed an overexpression vector, and expressed it in situ in sweetpotato to obtain transgenic seedlings. The experimental results demonstrated that transgenic sweetpotato plants overexpressing IbHSP18.0 exhibited longer shoots, more leaves, higher photosynthesis rates, more abundant roots, as well as higher biomass and K+ accumulation under low K+ stress conditions. These improvements were correlated with elevated activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), along with the effective removal of excess hydrogen peroxide (H2O2) and malondialdehyde (MDA). Additionally, the expression of IbHSP18.0 in sweetpotato induced the expression of K+ channels (IbAKT1-1, IbAKT1-3, and IbKC1-1) and high-affinity K+ transporter IbHAK5 within roots. In conclusion, our findings suggest that IbHSP18.0 plays a crucial role in enhancing the tolerance of sweetpotato to low K+ stress by strengthening the antioxidant defense mechanisms and positively regulating the expression of genes involved in K+ absorption and transport.

Biomass-derived nano carbon dots (CDs) application and sweetpotato (SP) planting can alter soil microbial community structure. However, the impact of these treatments on soil microbial necromass carbon (MNC) and associated mechanisms remains unclear. In this study, we combined pot experiments and laboratory analyses to assess soil physicochemical properties, microbial community characteristics, metabolic enzyme activity and multivariate correlations, aiming to explore the determinants of soil MNC accumulation in Vertisol following CDs application and SP planting. The results showed inconsistent effects of CDs application on soil bacterial and fungal necromass C content. Although CDs application increased bacterial richness and the relative abundances of Proteobacteria, Firmicutes and Cyanobacteria in the absence of SP planting, it failed to enhance bacterial necromass C accumulation. In contrast, CDs application improved soil fungal necromass C content regardless of SP planting. Besides directly increasing soil organic carbon (SOC) concentrations, both CDs application and SP planting enhanced the contributions of fungal necromass C to SOC. However, SP planting neither increased soil dissolved organic carbon (DOC) nor altered the compound contents in DOC solution. Extracellular enzymes related to C-cycling (e.g., (3-alpha-cellobiohydrolase and (3-1,4-xylosidase) also significantly diminished under SP planting without CDs application. Linear discriminant analysis (LDA) identified distinct bacterial and fungal genera between the CDs application and SP planting treatments. Structural equation models (SEMs) revealed that the reduced accumulation of bacterial necromass C was primarily driven by increased (3-1,4-glucosidase activity and shifted in bacterial community composition, which limited microbial substrate utilization and growth. The increased fungal necromass C accumulation was attributed to altering fungal community structure and decreasing alpha-diversity, which promoted necromass formation through sequential assimilation, synthesis, and turnover of CDs and SP carbon inputs. These results highlight the differential responses of bacterial and fungal necromass accumulation to CDs application and SP planting, providing novel insights into the regulatory roles of nano CDs and plant-microbe interactions in SOC sequestration processes in Vertisol.

Plants cope with drought stress by strengthening their survival and growth capabilities through enhancing potassium absorption and utilization. In this study, we evaluate transgenic sweetpotato plants overexpressing potassium transport IbHAK5 responses to drought stresses. Overexpression of IbHAK5 can improve potassium ion (K+) absorption ability under normal condition and drought stress, which may result in the increased drought stress tolerant in transgenic plants. The transgenic plants displayed higher drought stress tolerant than wild-type plants by increasing relative water content (RWC) and alleviating oxidative stress. Transcriptome analysis further identified differentially expressed genes (DEGs) encoding aquaporins and screened K+ channel, peroxidase (POD), glutathione S-transferase (GST), and stress-related genes up-regulated by drought stress, which may provide valuable insights for breeding programs to improve drought stress tolerance. These findings broaden our understanding of the role of IbHAK5 in drought stress resistance, and provide some candidate genes for sweetpotato molecular breeding.

Tigecycline is a last resort antibiotic that is used to treat serious infections; however, some bacteria have developed tigecycline resistance by producing a tigecycline-inactivating enzyme or tigecycline resistance efflux pump, encoded by tet(X) and tmexCD-toprJ genes, respectively. Tons of seafood are consumed annually in China; however, whether seafood harbors tigecycline-resistant bacteria is not known. In this study, we isolated various tigecycline-resistant bacteria from retail seafood; among these, Shewanella was the predominant tigecycline-resistant genus (33/76, 43.4%). Genomic sequencing revealed that two Shewanella strains carried the tet(X4) gene, while one Shewanella chilikensis strain co-harbored tmexCD2-toprJ2 and blaNDM-1 genes. The tet(X4) and tmexCD2-toprJ2 were found to be located on novel members of the SXT/R391 family of integrated conjugative elements (ICEs). As per our knowledge, this is the first report on the emergence of SXT/R391 ICEs carrying tet(X4) or tmexCD2-toprJ2 gene in Shewanella strains. The SXT/R391 family ICEs could mediate the spread of tigecycline resistance genes among aquatic bacteria, and contact between seafood and consumers may lead to the dissemination of tigecycline-resistant bacteria. Our study revealed that Shewanella spp. may act as potential reservoirs of tigecycline resistance genes.

V. furnissii is a marine bacterium capable of infecting both invertebrates and humans. However, the mechanisms underlying its drug resistance and virulence remain largely elusive. In this study, we isolated a multidrug-resistant V. furnissii strain, MT14, from bivalve mollusks. Genomic analysis revealed that MT14 carries a novel pAQU-type plasmid, designated pMT14, which harbors six antibiotic resistance genes: qnrS2, qnrVC6, dfrA31, tetA; sul2, and blaGMA-1. Notably, blaGMA-1 and its variants confer resistance to penicillin-class antibiotics, including ampicillin, amoxicillin, and carbenicillin. Comparative genomic analysis further revealed that V. furnissii strains commonly encode T6SS1, T6SS2, and the hemolysin gene vfh, while only five sequenced strains carry zot toxin gene. To our knowledge, this is the first report of zot in V. furnissii. In addition, the absence of drug resistance genes in the majority of genomes (73.3%, 22/30) suggests that such traits are not intrinsic to the species but have been acquired by specific strains, likely through plasmid transfer or other mobile genetic elements. The emergence of blaGMA-1 and zot in V. furnissii represents a potential public health concern, underscoring the need for enhanced surveillance of antimicrobial resistance in marine pathogens.

Crop rotation is a key strategy to mitigate the challenges associated with tobacco monoculture, such as soil nutrient depletion and microbial community imbalance. This study investigated the effects of different preceding crops-continuous tobacco (CK), barley (T1), and rapeseed (T2)-on soil potassium (K) forms, K uptake and allocation in tobacco plants, and soil bacterial communities. A randomized complete block design was employed with three replications per treatment. Soil samples were collected at multiple time points to analyze dynamic changes in various K forms (total K, available K, exchangeable K, non-exchangeable K, water-soluble K, mineral K). The bacterial community composition was assessed via 16 S rRNA gene sequencing at tobacco maturity. Key findings include: (1) Preceding crops T1 and T2 significantly enhanced soil available K (increased by 0.55-1.65 times), exchangeable K (1.85-5.77 times), and water-soluble K (3.35-7.23 times) compared to CK at maturity, and promoted the release of non-exchangeable and mineral K. (2) At harvest, the leaf K content in the T2 treatment reached 3.17%, significantly higher than in CK, indicating improved K allocation to leaves. (3) Bacterial community richness (Chao1 index) and diversity (Shannon index) were highest in T2, followed by T1 and lowest in CK. The dominant phyla were Proteobacteria, Actinobacteria, and Acidobacteria, whose relative abundances increased under rotation. The rapeseed rotation (T2) most effectively enhanced soil K supply, bacterial diversity, and leaf K accumulation. These results demonstrate that selecting appropriate preceding crops, particularly rapeseed, can optimize soil K availability, improve bacterial community structure, and enhance potassium utilization efficiency in tobacco, providing a theoretical basis for sustainable tobacco cultivation.

Aeromonas hydrophila, an opportunistic pathogen, often encodes Type VI Secretion System (T6SS) genes. However, the specific functions of T6SS, particularly in the context of clinical strains, remain poorly understood. In this study, we characterize a multi-drug-resistant strain, AH54, which possesses a complete and functional T6SS, composed of a structural cluster and two homologous auxiliary clusters (Aux1 and Aux2). Each auxiliary cluster encodes two distinct effector proteins: a rearrangement hotspot (Rhs) protein and a proline-alanine-arginine repeat (PAAR) protein-Rhs1/PAAR1 in Aux1 and Rhs2/PAAR2 in Aux2. Our findings reveal that AH54 assembles a fully operational T6SS capable of delivering these effectors, driving inter-bacterial antagonism. Interestingly, the T6SS activity in AH54 is temperature-regulated, with enhanced secretion and antibacterial activity at lower temperatures. To protect itself from self-intoxication, AH54 produces immunity proteins (Tsi1-Tsi4) that neutralize the toxic effectors. While PAAR1 and PAAR2 are critical for Hcp secretion, immunity proteins Tsi3 and Tsi4 do not cross-protect against PAAR effectors, suggesting distinct roles for each PAAR protein in optimizing AH54's competitive fitness. In addition, using a Dictyostelium discoideum phagocytosis model, we demonstrate that Rhs2, a metal ion-dependent DNase effector, plays a crucial role in protecting AH54 from eukaryotic predation via T6SS. These findings highlight the pivotal role of T6SS in bacterial competition and pathogenesis, offering new insights into the virulence mechanisms of A. hydrophila.

Potassium is a vital element in sweetpotato that plays important roles during its growth and development. In this study, potassium transporter IbHAK5, which is homologous to Arabidopsis HAK5, was cloned and overexpressed in sweetpotato. IbHAK5 encoded a protein of 739 amino acids and localized in the plasma membrane. Two IbHAK5-overexpressing transgenic lines with the highest expression level of IbHAK5 were screened for K+-deficiency stress tolerant assay. Compared with wild type sweetpotato plants, transgenic plants grew well with higher chlorophyll content, and maintain great higher K+ contents via decreasing more K+ effluxes under low potassium ion (− K+) stress condition. Additionally, IbHAK5 can help plants improve root morphology and increase endogenous hormone IAA content under both normal condition and − K+ stress, which may result in the increased root K+ absorption ability. The results indicated that IbHAK5 play an important role in sweetpotato response to − K+ stress, as well as support molecular-assisted breeding with the IbHAK5 gene.

Type VI secretion systems (T6SSs) are widely distributed among Vibrio species, yet their roles in the coexistence of toxigenic and non-toxigenic strains remain unclear. Here, we report an orphan T6SS effector-immunity module, T6SS effector specific to Vibrios (TseVs)-cognate immunity protein (TsiVs), primarily harbored by non-toxigenic Vibrio cholerae. TseVs exhibits robust vibriocidal activity, specifically targeting susceptible Vibrios lacking the TsiVs. TseVs forms dual-membrane, ion-selective pores that collapse Na+/K+ homeostasis, resulting in membrane depolarization and ATP depletion. Remarkably, non-Vibrio bacteria evade TseVs through proton motive force (PMF)-dependent resilience, uncovering an immunity-independent defense strategy. Furthermore, tseVs-positive non-toxigenic V. cholerae strains are globally distributed and have dominated in recent decades, highlighting TseVs's ecological significance in Vibrio population dynamics. By linking TseVs bioenergetic targeting mechanisms to Vibrio population shifts, we demonstrate how T6SS effectors shape microbial genetic diversity. Our findings suggest that TseVs represents a promising model for precision antimicrobial strategies, minimizing collateral damage to commensal microbiota.

Fertilization are commonly used strategies to alleviate continuous cropping obstacles, but long-term stationary fertilization also causes varying degrees of soil barriers that hinder the growth of crop with the extension of planting years. However, there was currently a lack of systematic research on which soil properties change caused by long-term stationary fertilization were the reasons for the production obstacles in sweetpotatoplanting fields. Here, soil samples from a 21-year-old continuously sweetpotato-planting field covering four fertilizations (CK: no fertilizer; M: organic manure only; NPK: chemical fertilizer only; MNPK: chemical fertilizer plus organic manure) were collected and analyzed. Compared with CK, fertilization significantly increased soil microbial biomass carbon content, the activities of urease, invertase and alkaline phosphatase, and the increase amplitudes in these indicators was the largest in MNPK. Moreover, fertilization significantly decreased the relative abundance of harmful fungi (i.e., Gibberella_avenacea, , Alternaria_alternata, , Mortierella_alpina, , etc.) compared with CK. Especially, the relative abundance of fungal pathogens, Fusarium_oxysporum and Fusarium_proliferatum, , showed a trend of MNPK

Plant roots are sensitive to potassium (K+) deficiency signals. Therefore, regulating root growth by exogenous methods is a vital strategy to improve low K+ tolerance of sweetpotato. We studied the effects of exogenous indole-3-acetic acid (IAA) on growth, K+ absorption, and root characteristics in sweetpotato exposed to low K+ treatment (LK). LK significantly inhibited dry mass, K+ concentration and accumulation, as well as the root elongation (length) and branching (forks and crossings) in sweetpotato seedlings. However, exogenous IAA increased the length, ratio, and density of lateral roots and promoted absorption and accumulation of K+, which effectively alleviated the inhibitory effect of low K+. Exogenous IAA also increased the expression levels of auxin synthesis (IbYUC6 and IbTAR2) and transport (IbPIN1, IbPIN3, and IbPIN8) genes in leaves and roots, which promoted the increase of endogenous IAA content. Furthermore, exogenous IAA was more effective on low-K-tolerant variety (XS32) than low-K-sensitive variety (NZ1) under LK stress, depending on their different IAA synthesis and transport strategies. These results indicated that exogenous IAA enhanced root responsiveness of sweetpotato to low K+ stress by modulating auxin biosynthesis and transport, thereby improving the tolerance of sweetpotato to low K+ stress.

Improving the utilization efficiency of sweetpotato on soil legacy phosphorus (P) is not only a need for sustainable utilization of P resources, but also an urgent need for cost saving and efficiency enhancement in the sweetpotato industry. Nano carbon dots (CDs), as an exogenous regulatory measure, were sprayed (10 mL, 1.5 mg mL− 1) on sweetpotato seedlings (Shangshu 19 and Xushu 32) grown in low P stress (spraying ultra-pure water as control), after which the root morphological, physiological parameters and rhizosphere properties were analyzed. Foliar-applied CDs promoted the root growth (e.g., increasing root length, projected area, surface area, etc.), and increased the expression of root phosphate transport genes (PHO1, PHT1-4). Meanwhile, foliar-applied CDs significantly reduced the expression level of inositol phosphate of root, and improved phoD gene abundance in Shangshu 19 rhizosphere. For Xushu 32, the expression level of roots citric acid and oxalic acid, and the abundance of rhizosphere pqqC gene increased after spaying CDs. Principal coordinates analysis (PCoA) showed that phoD-harboring Tuwongella, Prosthecobacter, Leptolyngbya, Rubinisphaera, and pqqC-harboring Nitrincola, Novimethylophilus, Ramlibacter, Mycobacterium, Thiomonas played key roles on the solubilization of insoluble P in Shangshu 19 and Xushu 32 rhizosphere, respectively. These alterations could increase available P content in Shangshu 19 (53

Biomolecular encryption employing chemical modifications enables secure approaches for information storage and communications. However, constructing high information density pathways for rapid synthesis and readout remains a challenge to guarantee confidentiality, integrity, and availability (CIA). Here we develop a nanopore sequencing based protocol, demonstrated by complete substitution using 5-hydroxymethylcytosine (5hmC) for individual nucleotide recognition rather than sequential interactions. Such motif-insensitive methylation at the single-molecule level does not naturally exist and results in severe ion current disruption and a 67.2%-100% readout failure, which ensure its ability on the encryption of the data encoded inside the DNA. We further propose and establish an alignment-free DeepSME basecaller, which is a deep learning-based platform independent on prior models and knowledges. DeepSME utilizes a three-stage training pipeline that initiates tolerable for 11.55% errors, expands its neighboring k-mer dictionary model size from 4^6 to 4^9, and mitigates the errors by only three microbial genomes, giving rise to 92% precision with 92% recall. Fully 5hmC encrypted digital information were deciphered by DeepSME within 16× coverage depth. The versatile and transparent DeepSME pipeline and its F1-score performance of 86.4% surpassing all the state-of-the-art basecallers, support its great potential for meeting the rapidly increasing CIA demands of DNA-based secure communications. ### Competing Interest Statement Qingyuan Fan, Xuyang Zhao, Junyao Li, Ronghui Liu, and Yi Li have a patent filed with application number CN117238360A. The remaining authors declare no competing interests.

With the intensification of global climate change, high-temperature and drought stress have emerged as critical environmental stressors affecting tobacco plants’ growth, development, and yield. This study provides a comprehensive review of tobacco’s physiological and biochemical responses to optimal temperature conditions and limited irrigation across various growth stages. It assesses the effects of these conditions on yield and quality, along with the synergistic interactions and molecular mechanisms associated with these stressors. High-temperature and drought stress induces alterations in both enzymatic and non-enzymatic antioxidant activities, lead to the accumulation of reactive oxygen species (ROS), and promote lipid peroxidation, all of which adversely impact physiological processes such as photosynthetic gas exchange, respiration, and nitrogen metabolism, ultimately resulting in reduced biomass, productivity, and quality. The interaction of these stressors activates novel plant defense mechanisms, contributing to exacerbated synergistic damage. Optimal temperature conditions enhance the activation of heat shock proteins (HSPs) and antioxidant-related genes at the molecular level. At the same time, water stress triggers the expression of genes regulated by both abscisic acid-dependent and independent signaling pathways. This review also discusses contemporary agricultural management strategies, applications of genetic engineering, and biotechnological and molecular breeding methods designed to mitigate adverse agroclimatic responses, focusing on enhancing tobacco production under heat and drought stress conditions.

The dynamic monitoring information of the "specialized, refined, unique, and new" enterprise green quality immune system is the basic key data in enterprise green quality management and quality evaluation, which can reflect the latest status and trends of internal and external green quality information in real time. The key to optimizing and constructing a dynamic early warning technology system for green quality management in "specialized, refined, unique, and new" enterprises is to establish a unified response mechanism for sensitivity in implementing monitoring of all important aspects of green quality management. This article starts with three stages: concise and concentrated monitoring information, sorting and integrating monitoring information, and updating and obtaining monitoring information. It analyzes the construction process of a dynamic early warning technology system for a sensitive green quality management immune system, and enhances the resilience of the "specialized, refined, and innovative" enterprise green quality immune system.

Potassium is a vital element in sweetpotato that plays important roles during its growth and development. In this study, potassium transporter IbHAK5, which is homologous to Arabidopsis HAK5, was cloned and overexpressed in sweetpotato. IbHAK5 encodes a protein of 739 amino acids and localized in the plasma membrane. Two IbHAK5-overexpressing transgenic (HO) lines with the highest expression level of IbHAK5 were screened for K+-deficiency stress tolerant assay. Compared with wide type (WT) sweetpotato plants, transgenic plants grew well with higher chlorophyll content, and maintain great higher K+ contents via decreasing more K+ effluxes under low potassium ion (− K+) stress condition. Additionally, IbHAK5 can help plants improve root morphology and increase endogenous hormone IAA content under both normal condition and − K+ stress, which may result in the increased root K + absorption ability. The results indicated that IbHAK5 play an important role in sweetpotato response to – K+ stress, as well as support molecular-assisted breeding with the IbHAK5 gene.

Background Sweetpotato is a typical ‘‘potassium (K + ) favoring’’ food crop, which root differentiation process needs a large supply of potassium fertilizer and determine the final root yield. To further understand the regulatory network of the response to low potassium stress, here we analyze physiological and biochemical characteristics, and investigated root transcriptional changes in two sweetpotato genotypes, namely, - K tolerant “Xu32” and - K susceptible“NZ1”. Result We found Xu32 had the higher capability of K + absorption than NZ1 with better growth performance, higher net photosynthetic rate and higher chlorophyll contents under low potassium stress, and identified 889 differentially expressed genes (DEGs) in Xu32, 634 DEGs in NZ1, 256 common DEGs in both Xu32 and NZ1. The Gene Ontology (GO) term in molecular function enrichment analysis revealed that the DEGs under low K + stress are predominately involved in catalytic activity, binding, transporter activity and antioxidant activity. Moreover, the more numbers of identified DEGs in Xu32 than that in NZ1 responded to K + -deficiency belong to the process of photosynthesis, carbohydrate metabolism, ion transport, hormone signaling, stress-related and antioxidant system may result in different ability to K + -deficiency tolerance. The unique genes in Xu32 may make a great contribution to enhance low K + tolerance, and provide useful information for the molecular regulation mechanism of K + -deficiency tolerance in sweetpotato. Conclusions The common and distinct expression pattern between the two sweetpotato genotypes illuminate a complex mechanism response to low potassium exist in sweetpotato. The study provides some candidate genes, which can be used in sweetpotato breeding program for improving low potassium stress tolerance.

Background Vibrio furnissii is an emerging human pathogen closely related to V. fluvialis that causes acute gastroenteritis. V. furnissii infection has been reported to be rarer than V. fluvialis, but a multi-drug resistance plasmid has recently been discovered in V. furnissii. Methods During daily monitoring at a general hospital in Beijing, China, seven V. furnissii strains were collected from patients aged over 14 years who presented with acute diarrhoea between April and October 2018. Genome analysis and comparison were performed for virulence and antimicrobial resistance genes, plasmids and transposon islands, together with phylogenetic analysis. Antimicrobial resistance to 19 antibiotics was investigated using the microbroth dilution method. Virulence phenotypes were investigated based on type VI secretion system (T6SS) expression and using a bacterial killing assay and a haemolysin assay. Results Phylogenetic analysis based on single-nucleotide polymorphisms revealed a closer relationship between V. furnissii and V. fluvialis than between other Vibrio spp. The seven V. furnissii isolates were in different monophyletic clades in the phylogenetic tree, suggesting that the seven cases of gastroenteritis were independent. High resistance to cefazolin, tetracycline and streptomycin was found in the V. furnissii isolates at respective rates of 100.0%, 57.1% and 42.9%, and intermediate resistance to ampicillin/sulbactam and imipenem was observed at respective rates of 85.7% and 85.7%. Of the tested strains, VFBJ02 was resistant to both imipenem and meropenem, while VFBJ01, VFBJ02, VFBJ05 and VFBJ07 were multi-drug resistant. Transposon islands containing antibiotic resistance genes were found on the multi-drug resistance plasmid in VFBJ05. Such transposon islands also occurred in VFBJ07 but were located on the chromosome. The virulence-related genes T6SS, vfh, hupO, vfp and ilpA were widespread in V. furnissii. The results of the virulence phenotype assays demonstrated that our isolated V. furnissii strains encoded an activated T6SS and grew in large colonies with strong beta-haemolysis on blood agar. Conclusion This study showed that diarrhoea associated with V. furnissii occurred sporadically and was more common than expected in the summer in Beijing, China. The antibiotic resistance of V. furnissii has unique characteristics compared with that of V. fluvialis. Fluoroquinolones and third-generation cephalosporins, such as ceftazidime and doxycycline, were effective at treating V. furnissii infection. Continua laboratory-based surveillance is needed for the prevention and control of V. furnissii infection, especially the dissemination of the antibiotic resistance genes in this pathogen.