Soil amendments have been widely applied in the remediation of saline soil and the improvement of crops resistance to external stresses. However, the responses of soil microbial community composition, structure, function, and resource competition strategy to soil amendment in saline and alkaline soil remain unclear. In this study, we conducted a barrel experiment in which soil was mixed with NaCl and Na2CO3 to achieve a salinity level of 8 g·kg−1, and then placed in barrels with a diameter of 50 cm and a height of 60 cm, then the barrels were buried in cotton fields. And soil conditioner GS was applied to improve the salt-stressed and alkali-stressed soil. This study investigated the effect of soil conditioner GS on soil microbial life history strategies under simulated saline and alkaline stress during cotton flowering in saline soils. The study explore the effects of soil amendment GS on soil microbial life history strategies under simulated saline and alkali stresses during cotton flowering stage for saline soil. The results showed that saline and alkali stresses disrupted soil microbial succession and altered rhizosphere soil micro-environment. However, after the application of amendment in saline soil, the abundance of dominant bacteria (Subgroup_17) and fungi (Mortierella, Chaetomium), soil metabolic functions (biosynthesis of amino acids and fatty acid), soil K+ content and Si/N ratio significantly increased, while soil Na+ content and electrical conductivity (EC) significantly reduced. After the application of amendment in alkaline soil, the abundance of dominant soil bacteria (Aeromicronium, Rokubacteriales, RB41) and fungi (Mycosphaeralla, Aspergillus), phenylalanine metabolise and fatty acid biosynthesis pathways soil K+/Na+ ratio, organic carbon content, total nitrogen, and Si/N ratio significantly increased, while soil Na+ content, pH, and Si/C ratio significantly decreased. Application of soil amendment could significantly increased soil nutrient content,the formation of different life cycle strategies of soil microorganisms, so as to alleviate the saline stress and alkali stress. This study provides reference for alleviating the saline and alkaline stresses to cotton by influencing key soil microorganisms using soil amendment.

Soil conditioners have great potential in saline soil remediation. However, it is still unclear that how soil conditioners affect cotton photosynthesis to improve cotton resistance to saline and alkaline stresses. Therefore, we used the self-developed soil conditioner was used to clarify whether soil conditioner has a repair effect on cotton photosynthesis under saline and alkaline stresses. The photosynthetic performance and chlorophyll fluorescence characteristics of cotton leaves have increased in PY and PJ. Transcriptome and Proteome analysis results showed that Photosystem II protein, Chlorophyll A-B binding protein, Rubrerythrin and Cytochrome B6-F complex Fe-S subunit were up-regulated in the PY and PJ group. All above changes induced by conditioner application promoted chlorophyll biosynthesis, and regulation of the photosynthetic system. This study will deepen our understanding of the molecular mechanism of soil conditioner regulating cotton photosynthetic, and provide reference for saline and alkaline soil remediation in arid areas.

Soybean cyst nematode (Heterodera glycines, SCN) and southern root-knot nematode (Meloidogyne incognita, RKN) are major limitation to soybean production, with few resistance sources available. Using 199 and 177 chromosome segment substitution lines (CSSLs) derived from Glycine max cv. Suinong14 and G. soja accession ZYD00006, we evaluated resistance to SCN HG type 1.2.3.5.6.7 (race 4) and RKN race 1, and compared the loci with those previously mapped for SCN HG type 2.5.7 (race 5). Despite both parents being susceptible, many CSSLs exhibited resistance levels exceeding both parents, while others showed extreme susceptibility, demonstrating strong transgressive segregation. QTL mapping identified 6 FI-associated and 9 CGR-associated loci for SCN race 4, and 17–25 significant loci for RKN across two inoculum levels. Single resistance loci generally conferred only moderate effects, but the combination of multiple favorable alleles from both parents produced higher resistance. Comparative analysis revealed several shared QTL intervals among SCN races 4 and 5 and RKN race 1, suggesting partial common genetic control. These findings demonstrate that pyramiding multiple loci from wild and cultivated soybean can generate transgressive inheritance, producing resistant lines beyond parental performance and offering valuable targets for breeding durable, broad-spectrum nematode resistance.

The soybean cyst nematode (SCN, Heterodera glycines) relies on chemosensation for host localization and successful infection. Understanding the molecular basis of chemosensation is critical, as it determines the nematode's ability to locate and invade host roots. In the model nematode Caenorhabditis elegans, Transient Receptor Potential Vanilloid (TRPV) channels osm-9 and ocr-2 and the G-protein α subunit goa-1 mediate sensory perception and ion transport; however, their roles in SCN remain largely unexplored. Here, we cloned and characterized these three candidate genes, which showed predominant expression in the phasmids of preparasitic juveniles. RNA interference revealed distinct roles: Hg-goa-1 regulated locomotion, whereas Hg-osm-9 and Hg-ocr-2 controlled chemotaxis, particularly attraction under acidic and basic conditions. Silencing any gene reduced root penetration and reproduction, while gene interaction analyses suggested a cross-regulatory network. Collectively, these results identify the three genes as essential regulators of SCN chemosensation, locomotion, and parasitism, providing potential molecular targets for developing species-specific nematicides.

Understanding the molecular and metabolic interplay between Meloidogyne incognita and soybean (Glycine max) root exudates is essential for unraveling plant-nematode interactions. This study investigates the transcriptomic responses of M. incognita during the preparasitic stage and the metabolomic changes in soybean root exudates influenced by nematode activity. Transcriptomic analysis identified 846 differentially expressed genes in nematodes exposed to root exudates (S-Mi) compared with nematodes alone (Mi). Upregulated genes, including those encoding sensory receptors such as G-protein-coupled receptors, nuclear hormone receptors, acetylcholine receptors, and key effectors, indicate a shift toward parasitic readiness. The downregulation of detoxification genes (e.g., cytochrome P450) and the upregulation of lysosome-related genes, such as cathepsins L-like cysteine proteases suggest metabolic reprogramming to support infection. Metabolomic profiling identified 781 metabolites across S-Mi, Mi, and Soy (root exudates alone), with enriched pathways such as tyrosine metabolism and cytochrome P450-related detoxification. Interestingly, amino acids such as L-threonine and arginylthreonine were upregulated in S-Mi, suggesting their role in nematode attraction. Additionally, lipid-like metabolites, such as 3-epipapyriferic acid and physagulin F, were elevated, potentially influencing nematode behavior and modulating plant defense response. An integrated cellular model illustrates how nematode sensory receptors detect root signals, activating cyclic adenosine monophosphate, phospholipase C, and mitogen-activated protein kinase signaling cascades, as well as acetylcholine receptor-mediated ion channels, leading to effector gene activation and metabolic shifts. This study reveals a bidirectional interaction at the preparasitic stage, where soybean root exudates reprogram nematode metabolism, and nematodes, in turn, modify root exudates to influence plant defenses, offering novel targets for sustainable nematode management.

Soil salinization and alkalization can cause great losses to agricultural production in arid regions. Cotton, a common crop in arid and semi-arid regions in China, often encounters saline stress and alkaline stress. In this study, NaCl (8 g·kg−1), Na2CO3 (8 g·kg−1), and a compound material (an organic polymer compound material) were mixed with field soil before cotton sowing, and the ion content, photosynthetic characteristics, and metabolite levels of the new cotton leaves were analyzed at the flowering and boll-forming stage, aiming to clarify the photosynthetic and metabolic mechanisms by which compound material regulates cotton’s tolerance to saline stress and alkaline stress. The results showed that the application of the compound material led to an increase in the K+/Na+ ratio, stomatal conductance (Gs), efficiency of PSII photochemistry (ψPSⅡ), potential activity (Fv/Fo), and chlorophyll content (Chla and Chlb), as well as the abundances of D-xylonic acid and DL-phenylalanine in the NaCl treatments. Additionally, there were increases in the K+ content, K+/Na+ ratio, Chla/b ratio, net photosynthetic rate (Pn), transpiration rate (Tr), ψPSⅡ, and D-saccharic acid abundance in the Na2CO3 treatments. A correlation analysis and a metabolic pathway analysis revealed that the compound material mainly regulated the photosynthetic characteristics of and the ion balance in the new leaves through regulating the abundance of key metabolites when the cotton was under NaCl stress or Na2CO3 stress. Furthermore, the positive impact of the compound material on the cotton’s NaCl stress tolerance was stronger than that on the cotton’s Na2CO3 stress tolerance.

Soil salinization adversely affects soil quality and ecosystem. Many researches have tried to ameliorate saline soils by soil conditioners. However, little is known about the differences in the responses of soil bacterial communities to natural and artificial conditioners applied to saline soils. Therefore, in this study, the effects of natural humic acid (IK), synthetic polymer (IP), and composite material (IF) (mixture of IK and IP (1:1)) on bacterial community structure and functional genes in saline soil were evaluated to clarify their differences. The results showed that the application of the three soil conditioners significantly reduced soil pH and Na+ content but increased soil alkaline phosphatase, urease, invertase and catalase activities, bacterial diversity, and nutrients, compared to the control (no conditioner). IK application increased bacterial relative abundance (e.g., Subgroup_6, RB41, MND1, and KD4-96) and metabolic functions (e.g., Two-component system and Biosynthesis of amino acids) by increasing soil nitrogen and maintaining K+ and Na+ balance. IP application increased soil alkaline phosphatase and urease activities as well as bacterial relative abundance (e.g., Subgroup_6, RB41, MND1, Gemmatimonadaceae, and KD4-96) and metabolic functions (e.g., Quorum sensing and carbon metabolism) by increasing soil organic carbon/nitrogen content. IF application increased the bacterial relative abundance of Subgroup_6, RB41, and MND1 by increasing soil available nitrogen and regulated their metabolic pathways (e.g., ABC transporters and microbial metabolism). On the whole, IK, IP, and IF could regulate the structure and function of soil bacterial community in saline soils. This study clarifies difference in the effects of different soil conditioners on the amelioration of saline soils from the perspective of soil microbiology, and provides a reference for the amelioration of saline soils in arid areas.

Soil salinity mediates microorganisms and soil processes, like soil organic carbon (SOC) cycling. Yet, how soil salinity affects SOC mineralization via shaping bacterial community diversity and composition remains elusive. Therefore, soils were sampled along a salt gradient (salinity at 0.25 %, 0.58 %, 0.75 %, 1.00 %, and 2.64 %) and incubated for 90 d to investigate (i) SOC mineralization (i.e., soil priming effects induced by cottonseed meal, as substrate) and (ii) the responsible bacteria community by using high-throughput sequencing and natural abundance of 13C isotopes (to partition cottonseed-meal-derived CO2 and soil-derived CO2). We observed a negative priming effect during the first 28 d of incubation that turned to a positive priming effect after day 56. Negative priming at the early stage might be due to the preferential utilization of cottonseed meal. The followed positive priming decreased with the increase in salinity, which might be caused by the decreased α diversity of microbial communities in soil with high salinity. Specifically, soil pH and electrical conductivity (EC) along the salinity gradient were the dominant variables modulating the structure of the microbial community and consequently SOC priming (estimated by distance-based multivariate analysis and path analysis). By adopting two-way orthogonal projections to latent structures (O2PLS), priming effects were linked with specific microbial taxa; e.g., Proteobacteria (Luteimonas, Hoeflea, and Stenotrophomonas) were the core microbial genera that were attributed to the substrate-induced priming effects. Here, we highlight that the increase in salinity reduced the diversity of the microbial community and shifted dominant microorganisms (Actinobacteria and Proteobacteria: Luteimonas, Hoeflea, and Stenotrophomonas) that determined SOC priming effects, which provides a theoretical basis for understanding SOC dynamics and microbial drivers under the salinity gradient.

Nitrogen (N), an important element for crop growth, has a great impact on dry matter weight and yield. Currently, improving N fertilizer use rate is an urgent problem to be solved in agricultural production in the world. In this field experiment, a self-developed water-soluble polymer material (PPM) with water retention and slow-release characteristics was combined with different doses of N fertilizer (N300 (100% N), PN300 (PPM + 100% N), PN240 (PPM + 80% N), PN180 (PPM + 60% N), CK (no N and PPM)) to analyze the impacts on N uptake and use efficiency of wheat plants. The results showed that the combined application of PPM and N fertilizer significantly improved yield, plant height, biomass, and N uptake and use efficiency of drip irrigated wheat, and the PN240 group had the highest N use rate. In addition, the PN300 group had the highest yield. N use efficiency in the PN240 group was 40.23% higher than that in the N300 group. Therefore, the combined application of PPM and N fertilizer, especially PN240, can reduce the N fertilizer application rate by increasing N use efficiency. This study provides technical reference for improving the N use efficiency of drip-irrigated wheat in arid areas.

Unraveling the intricacies of soybean cyst nematode (Heterodera glycines) race 4 resistance and susceptibility in soybean breeding lines-11-452 (highly resistant) and Dongsheng1 (DS1, highly susceptible)-was the focal point of this study. Employing cutting-edge N6-methyladenosine (m6A) and RNA sequencing techniques, we delved into the impact of m6A modification on gene expression and plant defense responses. Through the evaluation of nematode development in both resistant and susceptible roots, a pivotal time point (3 days postinoculation) for m6A methylation sequencing was identified. Our sequencing data exhibited robust statistics, successful soybean genome mapping, and prevalent m6A peak distributions, primarily in the 3' untranslated region and stop codon regions. Analysis of differential methylation peaks and differentially expressed genes revealed distinctive patterns between resistant and susceptible genotypes. In the highly resistant line (11-452), key resistance and defense-associated genes displayed increased expression coupled with inhibited methylation, encompassing crucial players such as R genes, receptor kinases, and transcription factors. Conversely, the highly susceptible DS1 line exhibited heightened expression correlated with decreased methylation in genes linked to susceptibility pathways, including Mildew Locus O-like proteins and regulatory elements affecting defense mechanisms. Genome-wide assessments, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, and differential methylation peak/differentially expressed gene overlap emphasized the intricate interplay of m6A modifications, alternative splicing, microRNA, and gene regulation in plant defense. Protein-protein interaction networks illuminated defense-pivotal genes, delineating divergent mechanisms in resistant and susceptible responses. This study sheds light on the dynamic correlation between methylation, splicing, and gene expression, providing profound insights into plant responses to nematode infection.

Polymer materials have great potential for soil heavy metal contamination remediation, but the metabolic mechanism by which polymer amendments regulate the responses of soil-plant systems to cadmium (Cd) stress is still unclear. To clarify the metabolic mechanism by which a self-developed soluble polymer amendment (PA) remediates Cd contamination in cotton fields, the common and differential metabolites in soil and cotton leaves were analyzed during the critical period of cotton growth (flowering and bolling stage) in a field experiment. The results showed that Cd stress increased Cd concentration in the soil-cotton system, and reduced enzyme activity in soil and cotton leaves. Besides, Cd stress also reduced the abundance of α-linolenic acid in soil and the abundance of 2-Oxoarginine and S-Adenosylmethionine in cotton leaves. These ultimately led to reductions in weight, boll number, yield, and fiber elongation. However, the application of PA to the Cd-contaminated soil significantly reduced the soil exchangeable Cd (Ex-Cd) concentration by 41.43%, and increased the boll number, yield, and fiber strength by 14.17%, 21.04%, and 19.89%, respectively compared with the Cd treatment. The results of metabolomic analysis showed that PA application mainly affected the Nicotinate and nicotinamide metabolism pathway, Lysine degradation pathway, and Arginine and proline metabolism pathway in cotton leaves and soil. Besides, in these metabolic pathways, succinic acid semialdehyde of cotton leaves, saccharopine of soil, and S-Adenosylmethionine of soil and cotton had the most significant response to PA application. Therefore, the application of PA to Cd-contaminated soil can increase soil and cotton leaf enzyme activity and cotton yield (boll number and seed cotton yield) and quality (fiber strength), and maintain soil-plant material balance by regulating the distribution of Cd ions and key metabolites in the soil-cotton system. This study will deepen our understanding of the metabolic mechanism of PA remediating Cd-contaminated cotton fields, and provide a technical reference for the remediation of heavy metal contamination in drip-irrigated cotton fields in arid areas.

Summary Entomopathogenic nematodes (EPN) as an environmentally-friendly biocontrol agent in combination with low toxic insecticides can increase control efficacy against insect pests. In this study, Steinernema carpocapsae All (Sc-All) combined with four common insecticides was used to evaluate the control efficacy against chive root gnat (Bradysia odoriphaga), an important pest of vegetables, e.g., chive, onion or garlic. The compatibility of nematodes with insecticides and host-seeking behaviour were also evaluated by the laboratory bioassay. The results showed three insecticides (matrine, imidacloprid and chlorpyrifos) at the recommended concentrations (RC), 10% RC or 2% RC and insecticide phoxim at 10% RC or 2% RC had no effect on nematodes survival. Sc-All at 50 infective juveniles (IJ) per insect larva in the presence of the four insecticides at 10% RC demonstrated a potentiated, additive or a synergistic effect on the corrected mortality rates of insect up to 100% (imidacloprid) when compared with the corresponding insecticide and Sc-All alone. A synergistic effect resulting in lethal effect was found as early as at 24 h when 200 IJ of Sc-All per insect larva were combined with 10% RC imidacloprid, whilst only 9.4% and 0 corrected mortality were detected, respectively, when exposed to the same amount of imidacloprid and Sc-All alone. For the first time a Pluronic gel system assay revealed that the presence of insecticides significantly improved Sc-All host-seeking ability as early as 30 min post exposure. The results indicated that low doses of Sc-All-imidacloprid combination would be an effective strategy to control chive root gnat.

Fig. S1.Cumulative total amounts of CO2 evolved in different five salinity soils during 90 days of incubation without addition and with cottonseed meal addition.Error bars represent standard errors of the means (n =3)

Soybean cyst nematode (Heterodera glycines Ichinohe),a devastating pathogen in soybean, was chosen as a model system toinvestigate nematode behavior and gene expression changes in responseto acidic and basic pH and salt signals (pH 4.5, 5.25, 8.6, and 10and NaCl) through full-length transcriptome sequencing of 18 samples.An average of 4.36 Gbp of clean reads per sample were generated, and3972 novel genes and 29,529 novel transcripts were identified. Sequencestructural variation during or after transcription may be associatedwith the nematode's behavioral response. The functional analysisof 1817/4962 differentially expressed genes/transcripts showed thatsignal transduction pathways, including transmembrane receptors, ionchannels, and Ca2+ transporters, were activated, but pathwaysinvolved in nematode development (e.g., ribosome) and energy production(e.g., oxidative phosphorylation) were inhibited. A correspondingmodel was established. Our findings suggest that these receptors andion channels might be potential targets for nematicides or drug discovery.

我国植物寄生线虫病已经发展成仅次于真菌病害的第二大植物病害,防治难度极大.随着我国农业可持续发展的需求,一些高毒高效化学农药不断被禁用,导致可供选择化学杀线虫剂的产品非常有限,进而杀线植物资源备受广大线虫学者的关注.本文综述了具有杀线虫作用的植物资源,如根系分泌物、组织提取物等活性物质,对植物寄生线虫的作用机制及生产实践中对这些资源的应用情况,并针对目前存在的问题和对未来的研究趋势提出了展望,以期为具有杀线虫作用的植物及其资源的开发和应用提供材料、思路和理论依据.

Due to their tiny size, soil nematodes and plant-parasitic nematodes are challenging to homogenize and collect using traditional mortar and pestle methods. To overcome this, we developed a reliable and efficient nematode preparation and grinding method using the BioPulverizer. The method involves creating a modified sample ‘sandwich’ with liquid nitrogen-frozen nematode samples placed between two layers of aluminum foil. This ‘sandwich’ facilitates complete homogenization through cryogenic grinding without any sample loss during transfer. The powerful nematode grinding yields high-quality and high-quantity samples, suitable for nucleic acid release and subsequent molecular identification and other downstream applications.

Plant-parasitic nematode infective juveniles (J2) use phytochemical signals released into the rhizosphere to locate host roots. Amino acids are the second most abundant metabolites of root exudates, but it is unknown if they are associated with J2 chemotaxis. In this study, J2 chemotaxis and mortality of the soybean cyst nematode (Heterodera glycines) and root-knot nematodes (Meloidogyne incognita and M. hapla) were examined in response to 15 amino acids and the corresponding pH values for tested amino acid solutions were measured. Responses varied by amino acid and among the species. Significant attraction, determined by J2 count within amino acid solution dispensers after 24 h exposure, occurred with 19 out of 45 J2-amino acid combinations. Heterodera glycines, M. hapla and M. incognita were attracted to nine, three and seven amino acids, respectively. Strongest attractions were to acidic polar amino acids aspartate and glutamate (H. glycines, M. hapla) and basic polar arginine (M. hapla), as previously reported, acid and basic pH attracting nematodes, thereby indicating that pH might be one of the attraction factors for these amino acids. All three nematodes exhibited clustering behaviours, such as halo or balling formations, just outside amino acid solution dispensers, with H. glycines, M. hapla and M. incognita responding to four, 12 and two amino acids, respectively. Six of 15 amino acid solutions, representing a range of pH values, caused increased mortality. Certain aspartate and glutamate affected both H. glycines and M. hapla; arginine, aspartate, cysteine, lysine, methionine affected M. incognita; and cysteine caused complete mortality in M. hapla. All the results suggest that amino acids affect nematode attraction and mortality.

昆虫病原线虫与体内细菌共生,专性寄生在昆虫体内,在害虫生物防治中发挥着重要作用.昆虫病原线虫致病性研究是其高效应用的基础,涉及线虫及其共生细菌对昆虫的交互作用.本文针对斯氏属和异小杆属线虫的致病因子及这类线虫与寄主昆虫互作机制进行了综述,为昆虫病原线虫的致病机制研究和应用提供参考.

根结线虫病是番茄(Solanum lycopersicum L.)生产中一重要病害,为了筛选抗病品种,采用温室盆栽人工定量接种法,鉴定了黑龙江省21个番茄栽培品种对南方根结线虫(Meloidogyne incognita)的抗感反应,并且对筛选到的抗性品种接种北方根结线虫(M.hapla),以验证抗性品种是否含有抗南方根结线虫的Mi基因.结果表明,抗性对照VFNT对南方根结线虫表现为免疫,参试品种只有红春桃和水果番茄的病情指数表现为抗病,分别为12和20;红春桃和水果番茄对南方根结线虫繁殖参数(卵块数和卵的繁殖系数)分别为免疫和抗病,其它品种都表现为感病或高感;红春桃和水果番茄2个品种与VFNT一样对北方根结线虫均表现为感病,说明红春桃和水果番茄品种含有和VFNT一样的Mi-1基因.该研究从当地筛选出的红春桃和水果番茄为防治番茄南方根结线虫病提供有价值的抗病材料;同时,可以看出市售的多数番茄为感病甚至高感品种,这将给番茄根结线虫病的防治带来巨大困难.

Full-length transcriptome sequencing with long reads is a powerful tool to analyze transcriptional and post-transcriptional events; however, it has not been applied on soybean (Glycine max). Here, a comparative full-length transcriptome analysis was performed on soybean genotype 09-138 infected with soybean cyst nematode (SCN, Heterodera glycines) race 4 (SCN4, incompatible reaction) and race 5 (SCN5, compatible reaction) using Oxford Nanopore Technology. Each of 9 full-length samples collected 8 days post inoculation with/without nematodes generated an average of 6.1 GB of clean data and a total of 65,038 transcript sequences. After redundant transcripts were removed, 1,117 novel genes and 41,096 novel transcripts were identified. By analyzing the sequence structure of the novel transcripts, a total of 28,759 complete open reading frame (ORF) sequences, 5,337 transcription factors, 288 long non-coding RNAs, and 40,090 novel transcripts with function annotation were predicted. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of differentially expressed genes (DEGs) revealed that growth hormone, auxin-activated signaling pathway and multidimensional cell growth, and phenylpropanoid biosynthesis pathway were enriched by infection with both nematode races. More DEGs associated with stress response elements, plant-hormone signaling transduction pathway, and plant-pathogen interaction pathway with more upregulation were found in the incompatible reaction with SCN4 infection, and more DEGs with more upregulation involved in cell wall modification and carbohydrate bioprocess were detected in the compatible reaction with SCN5 infection when compared with each other. Among them, overlapping DEGs with a quantitative difference was triggered. The combination of protein-protein interaction with DEGs for the first time indicated that nematode infection activated the interactions between transcription factor WRKY and VQ (valine-glutamine motif) to contribute to soybean defense. The knowledge of the SCN-soybean interaction mechanism as a model will present more understanding of other plant-nematode interactions.