The sugar beet cyst nematode (Heterodera schachtii) is a globally distributed plant parasite that causes significant agricultural losses. It was recently detected for the first time in Xinjiang Uygur Autonomous Region, China. However, knowledge of the population genetics of this nematode is still limited, especially concerning the origin of H. schachtii populations in China. We genotyped H. schachtii populations from China and integrated global datasets to assess genetic diversity, population structure, and migration history. Global populations showed high genetic diversity, with the greatest variation in China, Germany, and the United States. Three genetic groups were identified: Group EA (Europe, North America, Oceania, Middle East), Group CN (China), and Group KR (Korea). Moderate differentiation was observed among most populations, with low genetic distance between Chinese and German populations. Gene flow analyses revealed frequent exchanges, especially asymmetric migration from Europe/Middle East to other regions. Demographic modeling supports that Chinese H. schachtii populations were derived from Germany, which is likely the center of origin for H. schachtii. Global H. schachtii populations exhibit complex migration patterns with significant genetic structure. The evidence for German ancestry of Chinese populations and asymmetric gene flow from Europe advances our understanding of this pathogen's global spread. Our findings will facilitate the selection of resistant cultivars and development of effective pest management strategies in northwestern China. © 2025 Society of Chemical Industry.

The vegetative mycelium of Pleurotus ostreatus (oyster mushroom) exhibits the ability to reduce nematode populations. This property may be utilized in integrated management programs targeting harmful nematodes such as Heterodera schachtii, a major pest of sugar beet crops. In addition to sugar beet, many other plant species serve as hosts for this nematode; susceptible plants promote H. schachtii development and population growth. Current control strategies rely on integrated plant protection methods, including the use of tolerant cultivars, fallowing, and trap crops such as oilseed radish and white mustard. This study aimed to determine whether sugar beet cv. Janetka or nematocidal plants—oilseed radish cv. Romesa and white mustard cv. Bardena—affect the nematocidal activity of P. ostreatus mycelium when applied together. Specifically, the influence of root or seed secretions from these plants on the activity of ten P. ostreatus mycelial strains was assessed using the model nematode Caenorhabditis elegans and the target pest H. schachtii. Experiments were conducted under laboratory conditions on water agar media colonized by P. ostreatus mycelium. Seeds or root exudates of the tested plants were applied to the mycelial surface. Following incubation, nematode mobility (C. elegans) and cyst entwining by the mycelium (H. schachtii) were evaluated, along with the ability of the mycelium to produce toxocysts. The results indicate that trap plants did not significantly alter the nematocidal activity of the mycelium. However, certain mycelial strains were slightly stimulated by seed diffusates or root exudates. Oilseed radish moderately influenced the nematocidal activity of four mycelial strains against C. elegans, whereas in the case of H. schachtii, similar effects were observed with white mustard. The mycelial elimination of H. schachtii occurred through cyst entwining, which was generally more effective in the presence of plant exudates. Overall, the findings demonstrate that incorporating trap crops such as oilseed radish cv. Romesa or white mustard cv. Bardena, as green manure in crop rotation systems, does not interfere with the nematocidal activity of P. ostreatus mycelium and simultaneously may enrich the soil with nutrients. The study further confirms that P. ostreatus maintains its ability to effectively entwine and eliminate H. schachtii cysts even in the presence of sugar beet, supporting its potential role as a biological control agent. To our knowledge, this is the first experiment that integrates the activities of trap plants and sugar beet with the nematocidal effects of P. ostreatus mycelium.

Parasitic nematodes are a significant concern in human and veterinary medicine as well as agriculture. In this study, we prepared twenty-seven 5-phenyl-1H-indole derivatives bearing various substituents on the phenyl ring and assessed their efficacy against nematodes. Using Caenorhabditis elegans, we selected the most potent compounds and evaluated their toxicity on selected animal and plant-parasitic nematode species. Compounds featuring 4-chloro, 4-fluoro, and 4-trifluoromethoxy groups on the phenyl ring inhibited the motility of exsheathed L3 larvae of Hemonchus contortus while exhibiting limited cytotoxicity in mammalian cell cultures. These compounds showed similar effects against the plant-parasitic nematodes Heterodera schachtii and Ditylenchus destructor, albeit with reduced potency. We propose that the compounds might act as inhibitors of mitochondrial complex II as inferred from molecular modeling, decreased mitochondrial membrane potential, and reduced activity in C. elegans complex II mutants.

Summary Plant-parasitic nematodes (PPN) are economically important crop pests. Cyst nematodes undergo embryogenesis within the egg and arrest at the second-stage juvenile. Within the egg the nematode is bathed in perivitelline fluid, which contains the protein vitellogenin. In Caenorhabditis elegans there are six genes encoding four protein subunits that produce two complexes whose roles in nematode development include transporting lipids, providing amino acids, influencing post-embryonic phenotypes and providing some environmental protection against bacterial infection. Annexins are a family of proteins also found in perivitelline fluid. Neither of these groups of proteins have been fully characterised in PPN. Proteins present in the perivitelline fluid of cyst nematodes ( Globodera spp. and Heterodera schachtii ) were characterised by Western blot analysis using a panel of three antibodies (MAC-356, IACR-PC320 and UH-VitA), immuno-localisation studies, MALDI-TOF and LC/MS. The monospecific polyclonal antibody IACR-PC320 to an annexin from vitelline fluid recognised a band at approx. 34 kDa in H. schachtii that was slightly larger, approx. 35 kDa, in G. pallida . The antibody UH-VitA, raised to a short synthetic peptide (EQQLRSSGKWEFSLFNAEEREG) and identified as having 86% similarity to sequences of vitellogenins identified from the published genomes of Globodera pallida , G. rostochiensis and H. schachtii , was shown in immuno-localisation studies to be present in seam cells of H. schachtii . In the light of recent studies in C. elegans and the work presented here, we suggest that seam cells have a dual role across Nematoda, e.g. , they are: i ) important in the regulation and development of the cuticle; and ii ) responsible for the origin and diversity of the cuticle surface coat and thereby play a key role in microbial immunity.

Plant-parasitic cyst nematodes, such as Heterodera schachtii, cause substantial crop losses world-wide and induce specialized feeding structures in host roots, yet the molecular mechanisms underlying feeding structure initiation and development remain poorly understood. We introduce RNA tomography for plants, a powerful untargeted spatial transcriptomics technology that allows studying gene expression at high spatial resolution. We applied RNA tomography to Arabidopsis (Arabidopsis thaliana) roots infected with H. schachtii, capturing 96 consecutive cross sections of 20 micrometers at 1- and 2-d post inoculation (dpi). We identified the location of the nematode's pharyngeal glands, the organs where most effectors are produced, using marker genes, and discovered multiple uncharacterized H. schachtii genes expressed in the same region. Additionally, we mapped the Arabidopsis spatial gene expression response upon nematode infection, revealing that some genes are expressed in a specific section. Our findings provide novel insights into early nematode parasitism. RNA tomography offers a powerful new approach to understanding plant cellular organization and interactions under various conditions, including development and responses to biotic and abiotic stresses.

Heterodera schachtii, a nematode primarily feeding on sugar beet and cruciferous plants, e.g., rapeseed, cabbage, broccoli, mustard, and radish, had a significant impact on Camelina sativa (L.) Crantz. The isolation of H. schachtii cysts from C. sativa roots and a known data gap regarding their development on this plant prompted an investigation into their interaction. A pot experiment conducted under controlled conditions in a growth chamber showed that H. schachtii completes its full development cycle in the roots of spring (UP, Smielowska, Borowska, Omega) and winter (Lemka, Maczuga, Luna, Przybrodzka) camelina cultivars at temperatures of 15, 20, and 25 °C. Female nematodes and cysts were most abundant in the Omega cultivar at 20 °C, averaging 9.25 per plant. Nematode feeding did not affect the height or fresh weight of the plants. Plants of the Przybrodzka cultivar had fewer leaves than the control plants. More siliques were observed on the control plants of the UP cultivar kept at 15 °C and those of the UP and Borowska cultivars at 20 °C. Under natural conditions, the number of eggs and larvae in the soil decreased by approximately 50% during the camelina growth cycle for both spring and winter biotypes.

Upon pathogen infection, plants trigger a reactive oxygen species (ROS) burst to activate immunity. Although some effectors secreted by plant-parasitic nematodes are known to suppress ROS-mediated immunity, there are limited studies examining the regulation of respiratory burst oxidase homologs (RBOH)-dependent ROS pathways by these nematodes. Using developmental expression analysis, in situ hybridization, and immunohistochemical tests, we found that both Hs28B03 and Hs8H07 were expressed and secreted during the early parasitism by Heterodera schachii. Transgenic Arabidopsis plants were used to assess the role of Hs28B03 and Hs8H07 in H. schachii parasitism. Yeast two-hybrid was used to identify host targets in Arabidopsis. We identified Hs28B03 and Hs8H07 from H. schachtii, which play a crucial role in promoting nematode infection and parasitism, as well as inhibiting host immune responses. Hs28B03 and Hs8H07 harbor the SKP1/BTB/POZ domain and exhibit the capacity to mimic the host's SKP1 proteins, allowing them to regulate the ubiquitin pathway within the plant. Hs28B03 and Hs8H07 specifically target and degrade the host's AtSRC2 protein, inhibiting the Ca2+-dependent production of ROS mediated by RBOHF, enhancing Arabidopsis susceptibility to H. schachtii. In conclusion, nematodes can secrete effectors that mimic plant ubiquitination pathway components, suppressing ROS bursts via the RBOHF pathway, thereby facilitating parasitism.

Sugar beet cultivation is significantly impacted by Heterodera schachtii, requiring effective and sustainable management practices to ensure crop productivity and soil quality. The efficacy of nine compost and manure-based organic amendments was investigated for their potential to manage sugar beet cyst nematode (SBCN) populations and enhance sugar beet yield and quality. A multi-phase research approach was employed, which included laboratory egg-hatching assays, greenhouse trials, and microplot experiments conducted under semi-field conditions. In laboratory egg-hatching experiments, poultry and swine manure consistently demonstrated significantly lower hatching rates compared to water and other treatments, suggesting their potent inhibitory effects on nematode reproduction. The suppressive effects of organic amendments were confirmed in greenhouse trials, where poultry manure and Layer Manure® were shown to reduce cyst, egg, and juvenile populations at higher application rates. In microplot trials, these amendments maintained their effectiveness, achieving significant reductions in SBCN populations and enhancing sugar beet yield and Brix percentage, which indicated improved sugar content. Furthermore, organic amendments were found to stimulate beneficial soil nematode populations, with poultry manure increasing bacterivore and fungivore nematodes. The results underscored the potential of organic amendments, particularly poultry manure and Layer Manure®, as alternatives to chemical nematicides. These amendments were demonstrated to offer a multifaceted approach to nematode management while improving crop productivity and soil quality.

Cyst nematodes are among the major plant-parasitic nematodes worldwide, and they cause significant damage to Brassicaceae crops, including Kimchi-cabbage, in Korea. To survey the incidence of cyst nematodes in Kimchi-cabbage fields, 469 soil samples were collected from the main producing areas between 2018 and 2021. Only cyst nematodes belonging to the genus Heterodera were investigated, and the overall nematode incidence was found to be 40%. Regionally, the highest incidence was observed in Taebaek, reaching 89%, with mean densities of cysts and eggs per 500 cm³ of soil recorded at 522 and 49,734, respectively. Based on Bayesian analysis of the mitochondrial DNA cytochrome c oxidase subunit I gene sequence, the cyst nematodes were identified as four species: clover cyst nematode (Heterodera trifolii, HT, frequency: 78%), soybean cyst nematode (H. glycines, HG, 11%), sugar beet cyst nematode (H. schachtii, 4%), and white soybean cyst nematode (H. sojae, HSo, 2%). Mixed infestations were found in some fields, with HT + HG (4%) and HG + HSo (1%). These results indicate that HT is the dominant species in the main Kimchi-cabbage producing areas in Korea. In conclusion, implementing effective HT management strategies is critical to minimize economic losses in Kimchi-cabbage production in Korea.

Cyst nematodes, some of the most important plant-parasitic nematodes globally, cause major damage to Chinese cabbage and soybean plants in Korea. Cysts are commonly used for cyst nematode bioassays because many eggs are included inside cyst. Traditionally, cysts are extracted from the soil using the paper strip method or the centrifugal flotation method (CFM) combined with sieving. The specific gravity of sugar solution (SGSS) is often used in the CFM; however, the efficiency of cyst extraction and egg hatching in the CFM has not been studied. In this study, we assessed the effects of SGSS in a specific gravity range of 1.15 to 1.30 in the CFM on the cyst extraction and egg hatching of clover cyst nematode (Heterodera trifolii) and sugar beet cyst nematode (H. schachtii). High SGSS in the CFM within the range of 1.15 to 1.30 was positively correlated with the extraction of more cysts. Egg-hatching rates were not different between SGSSs, indicating that SGSS did not directly affect egg-hatching rates. These results showed that the cysts of cyst nematodes can be efficiently extracted with high SGSS in the CFM.

Rhizosphere microbes, particularly bacteria, are essential for controlling plant-parasitic nematodes (PPNs) through various mechanisms. However, the plant's age and the genetic composition of nematode populations can significantly influence the inhibitory effectiveness of these microbes against the beet cyst nematode Heterodera schachtii. In this study, rhizosphere microbes were isolated from 39-day-old and 69-day-old resistant oilseed radish plants to evaluate their impact on the penetration of the second-stage juveniles (J2s) originating from four genetically distinct H. schachtii populations. The suppression of J2s penetration by the attached microbes varied across the nematode populations, which displayed differing levels of aggressiveness toward the resistant oilseed radish. Furthermore, differences in the alpha and beta diversity of rhizosphere bacteria were observed between the 39-day-old and 69-day-old plants, leading to variations in the bacterial attachment among the four nematode populations. In summary, the effectiveness of resistant catch crops against H. schachtii is influenced by the pathogenicity of the nematode populations and their interactions with the rhizosphere microbial community shaped by the plant's age.

Cyst nematodes remain a major threat to global agricultural production, causing huge losses. To understand the parasitism of the cyst nematodes Heterodera trifolii (HT) and Heterodera schachtii (HS), we constructed whole-genome assemblies using short- and long-read sequencing technologies. The nematode genomes were 379 Mb and 183 Mb in size, with the integrated gene models predicting 40,186 and 18,227 genes in HT and HS, respectively. We found more than half of the genes predicted in HT (64.7%) and HS (53.2%) were collinear to their nearest neighbor H. glycines (HG). Large-scale duplication patterns in HT and segmental duplications of more than half of the orthologous genes indicate that the genome of HT is polyploid in nature. Functional analysis of the genes indicated that 65.6% of the HG genes existed within the HT genome. Most abundant genes in HT and HS were involved in gene regulation, DNA integration, and chemotaxis. Differentially expressed genes showed upregulation of cuticle structural constituent genes during egg and female stages and cytoskeletal motor activity-related genes in juvenile stage 2 (J2). Horizontal gene transfer analyses identified four new vitamin biosynthesis genes, pdxK, pdxH, pdxS, and fabG, of bacterial origin, to be first reported in HT and HS. Mitogenomes of HT, HS, and HG showed similar structure, composition, and codon usage. However, rates of substitution of bases in the gene nad4l were significantly different between HT and HS. The described genomes, transcriptomes, and mitogenomes of plant-parasitic nematodes HT and HS are potential bio-resources used to identify several strategies of control of the nematode.

Cyst nematodes establish a highly specialized feeding structure called a syncytium in host roots by secreting effectors into a selected host cell that reprogram host development programs. The selected host cell undergoes distinct morphological, physiological, and gene expression changes, resulting in the fusion of hundreds of cells to create a novel cell type that does not normally exist in the host. Here, we profiled the transcriptome of the syncytium induced by the beet cyst nematode (BCN) Heterodera schachtii in Arabidopsis roots using laser capture microdissection and RNA sequencing. Aside from biological processes that are expected to be altered by nematode infection, we also found that genes annotated in nitrate and iron ion signaling and transport-related biological processes are significantly overrepresented in genes that are downregulated by BCN infection, suggesting that these ions may play important roles in BCN infection. Comparing the syncytium transcriptome with that of various root cell types showed that it was overrepresented by genes that are enriched in cells marked by ATHB15, a member of the HD-ZIP III transcription factor family that is highly expressed in the stem cell organizer of the root vasculature. These results suggest that the syncytium may partially adopt the molecular signature of a stem cell organizer, consistent with our previous hypothesis that BCN uses a stem cell organizer as an intermediate status for syncytium formation. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Purpose. To establish the effectiveness of treating sugar beet seeds with insecticides in limiting the development of heteroderosis in modern agrocenoses of the right-bank Forest-Steppe of Ukraine. Methods. General scientific ones: scientific hypothesis, experiment, observations, analysis, field research, laboratory analysis, mathematical and statistical analysis. Results. The cyst-forming beet nematode Heterodera schachtii Schmidt, which belongs to the ecological-trophic group of phytohelminths and is the causative agent of heteroderosis, is widely distributed in all beet-growing zones of Ukraine. At high population density (over 250- 300 eggs and larvae per 100 cm3 of soil), root crop losses can reach 65% or more. Microscopic size, rapid reproduction, long-term (up to 9 years) viability, resistance to abiotic factors greatly complicate effective control of the pathogen's population, which makes the existing integrated method of protection insufficient against the background of global changes in modern agrocenoses and necessitates the strengthening of its chemical component. Treatment of beet seeds with insecticides and their compositions makes it possible to reduce the population density of the first generation of the pathogen, the most dangerous for young plants, by 53.7-62.6%, which, despite its subsequent recovery, allows saving the plant density from excessive thinning at the time of harvesting by 4.1-9.1 thousand pcs/ha and reduce the yield losses of root crops by 2.6-9.9 t/ha, sugar production – by 1.3-1.72 t/ha. Conclusions. Treatment of sugar beet seeds with insecticides and their compositions is a fairly effective measure in limiting the density of the most harmful first generation of beet nematode, which allows saving a significant part of the crop from losses in modern agrocenoses, reduce the population density of the first generation by 60-62%.

Cyst nematodes use a stylet to secrete CLE-like peptide effector mimics into selected root cells of their host plants to hijack endogenous plant CLE signaling pathways for feeding site (syncytium) formation. Here, we identified ATHB8, encoding a HD-ZIP III family transcription factor, as a downstream component of the CLE signaling pathway in syncytium formation. ATHB8 is expressed in the early stages of syncytium initiation, and then transitions to neighboring cells of the syncytium as it expands; an expression pattern coincident with auxin response at the infection site. Conversely, MIR165a, which expresses in endodermal cells and moves into the vasculature to suppress HD-ZIP III TFs, is down-regulated near the infection site. Knocking down HD-ZIP III TFs by inducible over-expression of MIR165a in Arabidopsis dramatically reduced female development of the sugar beet cyst nematode (Heterodera schachtii). HD-ZIP III TFs are known to function downstream of auxin to promote cellular quiescence and define stem cell organizer cells in vascular patterning. Taken together, our results suggest that HD-ZIP III TFs function together with a CLE and auxin signaling network to promote syncytium formation, possibly by inducing root cells into a quiescent status and priming them for initial syncytial cell establishment and/or subsequent cellular incorporation.

Cyst nematodes use a stylet to secrete CLE-like peptide effector mimics into selected root cells of their host plants to hijack endogenous plant CLE signaling pathways for feeding site (syncytium) formation. Here, we identified ATHB8, encoding a HD-ZIP III family transcription factor, as a downstream component of the CLE signaling pathway in syncytium formation. ATHB8 is expressed in the early stages of syncytium initiation, and then transitions to neighboring cells of the syncytium as it expands; an expression pattern coincident with auxin response at the infection site. Conversely, MIR165a, which expresses in endodermal cells and moves into the vasculature to suppress HD-ZIP III TFs, is down-regulated near the infection site. Knocking down HD-ZIP III TFs by inducible over-expression of MIR165a in Arabidopsis dramatically reduced female development of the sugar beet cyst nematode (Heterodera schachtii). HD-ZIP III TFs are known to function downstream of auxin to promote cellular quiescence and define stem cell organizer cells in vascular patterning. Taken together, our results suggest that HD-ZIP III TFs function together with a CLE and auxin signaling network to promote syncytium formation, possibly by inducing root cells into a quiescent status and priming them for initial syncytial cell establishment and/or subsequent cellular incorporation.

Plant pathogenic nematodes play an important role in crop production and are difficult to control. One of them is Heterodera schachtii—a cyst nematode, pathogenic to sugar beet. Nature suggests a natural way to resolve this problem by using nematode-trapping fungi, one of which is Pleurotus ostreatus. It is one of the most widespread mushrooms in the world. It is a valuable and widely cultivated edible mushroom with nematocidal properties. The mycelium of this mushroom produces toxin droplets that paralyze nematodes, after which the nematodes become infected with the hyphae filament, resulting in their death. This feature can be put to practical use as a natural nematocidal agent. In this paper, we have described studies on the variability of the nematocidal properties in the progeny of three wild strains of P. ostreatus (Po1, Po2, Po4), obtained by crossing dikaryons with monokaryons (Buller phenomenon). The toxicity of mycelium was tested against the model organism Caenorhabditis elegans and against sugar beet pest—H. schachtii. The results of the study allowed the selection of the progeny heterokaryotic mycelia with the best parameters useful for in vitro control of both nematodes. They differed in the activity against C. elegans and H. schachtii, and in the toxic knobs production. The results indicated that the progeny of the Po1 strain presented a good ability to produce hyphal knobs in the presence of C. elegans, and progenies of the Po4 strain presented good quality of growth in preferred temperatures (10–25 °C). Three strains Po1 5dix27, Po2 20dix21, and Po4 2dix1, as well as a maternal strain Po4 controlled H. schachtii by entwining cysts better than other strains. These strains were moderately effective against C. elegans. Strains Po2 15dix17, Po4 1dix18, and Po4 1dix30 may be considered good controlling isolates against both tested organisms. The results of the research also clearly suggest that the killing properties of P. ostreatus mycelia should not be assessed only by their ability to produce toxic hyphal knobs. Their nematocidal properties also depend on other mechanisms developed by mycelia, which is observed as the lethality of nematodes. The results of this research will lead to a natural way to protect plants against nematodes. The research also proved the nematocidal properties of the wild strains to reduce the H. schachtii population in the soil.

The biological activity of bacterial rhamnolipids on Arabidopsis thaliana and the cyst nematode Heterodera schachtii is linked to their molecular structure

Plant-parasitic nematodes constrain global food security. During parasitism, they secrete effectors into the host plant from two types of pharyngeal gland cells. These effectors elicit profound changes in host biology to suppress immunity and establish a unique feeding organ from which the nematode draws nutrition. Despite the importance of effectors in nematode parasitism, there has been no comprehensive identification and characterisation of the effector repertoire of any plant-parasitic nematode. To address this, we advance techniques for gland cell isolation and transcriptional analysis to define a stringent annotation of putative effectors for the cyst nematode Heterodera schachtii at three key life-stages. We define 717 effector gene loci: 269 "known" high-confidence homologs of plant-parasitic nematode effectors, and 448 "novel" effectors with high gland cell expression. In doing so we define the most comprehensive "effectorome" of a plant-parasitic nematode to date. Using this effector definition, we provide the first systems-level understanding of the origin, deployment and evolution of a plant-parasitic nematode effectorome. The robust identification of the effector repertoire of a plant-parasitic nematode will underpin our understanding of nematode pathology, and hence, inform strategies for crop protection.

BackgroundPlant-parasitic nematodes are economically important pests responsible for substantial losses in agriculture. Researchers focusing on plant-parasitic nematodes, especially on finding new ways of their control, often need to assess basic parameters such as their motility, viability, and reproduction. Traditionally, these assays involve visually counting juveniles and eggs under a dissecting microscope, making this investigation time-consuming and laborious.ResultsIn this study, we established a procedure to efficiently determine the motility of two plant-parasitic nematode species, Heterodera schachtii and Ditylenchus destructor, using the WMicrotracker ONE platform. Additionally, we demonstrated that hatching of the cyst nematode H. schachtii can be evaluated using both the WMicrotracker ONE and by assessing the enzymatic activity of chitinase produced during hatching.ConclusionsWe present fast and straightforward protocols for studying nematode motility and hatching that allow us to draw conclusions about viability and survival. Thus, these methods are useful tools for facilitating fast and efficient evaluation in various fields of research focused on plant-parasitic nematodes.