Resistant Populations Research Articles

CYP72A15 confers resistance against penoxsulam to Echinochloa phyllopogon.

Monitoring and molecular mechanisms of resistance to complex III inhibitors in Tetranychus urticae populations from Türkiye.

Acetyl-coenzyme A carboxylase (ACCase) is a key herbicide target in grass species, with I1781L and D2078G mutations in the carboxyl transferase domain of plastidic ACCase conferring resistance to all ACCase inhibitor classes. The I1781L mutation was hypothesized to reduce the binding affinity of cyclohexanedione oximes (DIMs) due to increased steric hindrance at the binding site. Testing DIMs with a methyl group at the oxime carbon revealed reduced resistance in blackgrass with the I1781L mutation compared to the corresponding commercial herbicides. A correlation between the alkyl chain length and resistance factor (RF) was observed. Compound A1, featuring a methyl group, was also effective against D2078G and showed an RF of 5 or less across resistant populations, with herbicidal efficacy below 100 g a.i. ha-1. Homology modeling and molecular dynamics simulations suggest that van der Waals interactions between the ligand and specific residues in the receptor contribute to the observed change in activity.

Environmental factors contribute to antimicrobial resistance, a global health threat. Contaminated gutter water in urban areas spreads resistant bacteria, disrupting ecosystems and promoting biofilm formation, causing widespread concern. This study aimed to evaluate antibiotic-resistant bacterial populations across six gutter ecosystems in Roorkee, Uttarakhand, India during summer against different classes of antibiotics, identify presence of beta-lactamase, and explores total bacterial communities, and predicting metabolic pathways through 16S rRNA based metagenomic approach of V3 region. The highest resistant bacterial population was found in HL_NS-6, and HL_NS-2, with highly resistance to Penicillin (ampicillin and oxacillin), Cephalosporin (Cephalothin), aminoglycoside (Kanamycin), fluoroquinolone (ciprofloxacin), and Antifolate (Trimethoprim) class antibiotics. Beta-lactamase activity was detected in all samples except HL_NS-5, indicated by nitrocefin hydrolysis. The microbial community in the six samples were composed with the major families enterobacteriaceae (15.4%) and pseudomonadaceae (8.29%), covering 23.7% of the total population. The highest taxa were found in HL_NS-2 and HL_NS-4, while the largest genera were Pseudomonas (8.3%), Escherichia (8.2%), Hydrogenophaga (6.85%), and Candidatus Moranella (5.4%). There were 21.25% common bacterial genera were present as core microbiome and rest were signified the population diversity among the six-gutter microbiome. The coexistence of common metabolic pathways (citric acid cycle, carbon, nitrogen metabolism etc.), and streptomycin, glycosphingolipid, lipopolysaccharide, cyanoamino acid metabolism pathways might be induced the development of antibiotic resistance in gutter microbiome. This study suggests the presence of antibiotic-resistant bacteria with antibiotic resistant metabolic pathways, and beta-lactamase genes in urban gutter water, which could be harmful to both human health and environmental ecosystems.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-20043-4.

The phytopathogenic fungus Botrytis cinerea, which causes gray mold disease, has become a limiting factor on agricultural production. B. cinerea field control is made mainly using chemical fungicides, which has led to the spreading of resistant populations of this fungus. Thus, the quest of new fungicides molecules has been focused on synthesis of natural product-inspired compounds. The main aim of this work is to synthesize prenylated phenol derivatives and to assess their potential application as antifungal agents with minimal phytotoxic effects. Thus, new prenylphenols (4, 5, and 7) have been obtained by microwave irradiation with yields ranging from 2.4% to 42.9%, whereas compounds 8 and 9 were synthesized with yields of 25.6% and 54.1%, respectively. The effect of different concentrations of these compounds on B. cinerea spore germination, and their phytotoxic effect on tomato (Solanum lycopersicum L.) seed germination and root growth, were evaluated. Obtained results indicate that biological activities of all tested compounds are concentration-dependent. Interestingly, compound 7 exhibits the highest antifungal activity against B. cinerea spores (IC50 < 50 µg/mL) with minimal phytotoxicity on tomato seed germination and root growth. In contrast, compounds 2 and 3 are active against spores (IC50 = 461 and 325 µg/mL, respectively) but, at the same time, their phytotoxicity is important at the highest concentrations. These results indicated that the presence of hydroxyl and methyl substituents on the aromatic ring of these compounds induces variations in biological activities, and compound 7 could be a promising candidate as a sporicidal agent.

Hormonal alterations associated with polycystic ovary syndrome (PCOS) also impact bone metabolism, though it is unclear if this is bone-protective or not. Bone marker dysfunction has been reported in PCOS and appears to be associated with obesity. This study sought to determine whether a panel of bone marker proteins (BMPs) would be dysregulated in PCOS stratified by BMI as a potential biomarker for bone in PCOS. In this exploratory cross-sectional study, plasma was collected from 234 women (137 with PCOS and 97 controls) from a biobank cohort and compared to a nonobese, non-insulin resistant population (24 with PCOS and 24 controls). Slow Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement was undertaken for the following BMPs: sclerostin; Dickkopf-related protein-1; glycogen synthase kinase-3 alpha/beta; periostin; tumor necrosis factor ligand superfamily member 11; fibroblast growth factor 23; sphingosine kinase 1; sphingosine kinase 2; cathepsins A, B, D, E, G, L2, S and Z; parathyroid hormone; osteocalcin; tumor necrosis factor ligand superfamily member 11 (sRANKL) and interleukin-1 beta. Four BMPs differed in the PCOS cohort (whole set without matching for body mass index (BMI) or insulin resistance (IR)): periostin (p = 0.05), cathepsin L (p = 0.05) and osteocalcin (p = 0.02) decreased in PCOS, whilst cathepsin D (p = 0.02) increased; however, linear regression showed that only cathepsins D and L and osteocalcin differed. None of the BMPs differed in the nonobese women with and without PCOS, nor in obese PCOS and controls stratified by BMI greater than 30 kg/m2. In subgroup analysis, periostin (p = 0.001), sphingosine kinase 2 (p = 0.01) and cathepsin L (p = 0.001) were higher in obese versus nonobese PCOS (p = 0.01). Cathepsin Z (p = 0.02), sphingosine kinase 2 (p = 0.04) and lysosomal protective protein (p = 0.05) were lower in obese versus nonobese controls. Changes in BMPs indicative of impaired bone physiology were associated with BMI in both controls and PCOS, but did not differ between women with and without PCOS when BMI was matched. Hyperandrogenemia in PCOS did not affect BMP levels.

Thymol enhances the acaricidal effects of cypermethrin through the disruption of oocyte development in Rhipicephalus microplus (Acari: Ixodidae).

Cassava mosaic disease (CMD) is a major viral disease that causes severe yield loss in cassava cultivation in India. The host plant resistance breeding for CMD is the important strategy to control the disease spread. To understand the nature of disease resistance and identification of simple sequence repeat (SSR) markers closely associated with CMD resistance is important. To study the nature of resistance, seedling and clonal population developed by crossing Sree Jaya (Susceptible) and 9S127 (Resistant) and self-pollinating 9S127 parent were done and the population was evaluated for CMD disease scoring (1-5 scale) at 5 and 8 months after planting. The disease segregate in 1:1 ratio in the F1 and C1F1generation of Sree Jaya × 9S127 cross and 3:1 in the S1, C1S1 self-pollinated progenies of 9S127 parent. It confirms the gene in the resistant parent is heterozygous (Rr) and single dominant gene (RR) is controlling the resistance. In this mapping population, Sri Lankan Cassava Mosaic Virus (SLCMV) is prevalent in all the samples. A total of 14 CMD associated SSR markers were screened in the progenies using bulk segregant analysis (BSA) method. Out of 14 markers, two markers SSRY28, NS158 co-segregate with CMD resistance in the population. These markers can be used for marker assisted selection (MAS) for CMD screening in the seedling population to identify true resistant lines for further breeding trials.

Winter is a formidable challenge for ectotherms that inhabit temperate climates. The extent to which winter conditions drive rapid adaptation, and separately, how selection from novel stressors affects adaptation to winter, remain poorly understood. Here we use replicate populations of Drosophila melanogaster in a field experiment to test i) whether winter conditions drive rapid adaptation and ii) for trade-offs between insecticide resistance and overwintering survival. Following a longitudinal field experiment investigating the evolution of insecticide resistance, we tracked subsequent evolution during an overwintering period. In unexposed control populations, we detected parallel evolutionary shifts indicative of adaptation to winter conditions in multiple traits, including body size and fecundity. Additionally, populations that had evolved insecticide resistance during the growing season were more likely to go extinct than control populations. Further, both control and resistant populations showed patterns of lower resistance following the winter period, suggestive of a trade-off between overwintering success and insecticide resistance. Rapid evolutionary responses to winter conditions, and potential costs of resistance, provide important context for understanding overwintering performance in temperate insects with implications for pest management and ecosystem services.

The two-spotted spider mite (Tetranychus urticae Koch) (Acari: Tetranychidae) is one of the most widespread and destructive phytophagous mite species, occurring across all climatic zones worldwide. Currently, the control of spider mites in crop protection relies primarily on chemical acaricides. However, the selection of resistant populations to their active ingredients is reducing their efficacy. The aim of the present study was to assess the susceptibility of T. urticae to a native isolate of entomopathogenic nematodes, Steinernema feltiae Filipjev ZWO21, under laboratory conditions. The experiment was conducted using Petri dishes, each containing 22–28 adult T. urticae. Infective juveniles (IJs) of the nematodes were then applied at a dose of 8000 IJs per dish (±300 IJs per mite). Petri dishes with mites treated with nematodes were placed in a Sanyo incubation chamber at 25 °C and 60% relative humidity. After three days, dead mites were collected from the Petri dishes and dissected, and mortality was subsequently determined. The present study confirmed that the S. feltiae ZWO21 isolate exhibited considerable potential for the biological control of T. urticae, causing 37.5–83.3% (mean 57.0%) mortality in this pest species. Although this result indicates a moderate efficacy when nematodes are applied alone, it also underscores the relevance of further research into their integration with other control strategies, including acaricides, within integrated pest management (IPM) programmes.

The fall armyworm (Spodoptera frugiperda, J. E. Smith) is a highly invasive pest causing significant damage to global crops and has developed resistance to multiple insecticides. Cytochrome P450 monooxygenases (P450s) are crucial for insecticide detoxification and resistance. However, the roles of P450 genes in mediating resistance to emamectin benzoate in S. frugiperda are unclear. This study examined the expression of 15 P450 genes in susceptible and emamectin benzoate-resistant populations. CYP9A32 was highly expressed in resistant populations (EBRS, FZJRS, and FHKRS) with resistance ratios of 32.7-, 28.7-, and 48.9-fold, respectively. P450 activity was significantly higher in these resistant populations than in the susceptible population (SS), with increases of 3.52-, 7.23-, and 6.12-fold. In contrast, no significant differences were observed in glutathione S-transferase and esterase activities. RNA interference (RNAi) of CYP9A32 increased susceptibility to emamectin benzoate and reduced P450 activity by 38.74%, 26.38%, and 21.03% in SS, EBRS, and FZJRS populations, respectively. Mortality rates of 3rd instar larvae treated with emamectin benzoate at median lethal concentration dosage increased significantly due to CYP9A32 RNAi, with increases of 92.98%, 64.06%, 51.61%, and 65.52% for SS, EBRS, FZJRS, and FHKRS populations. Conversely, transgenic Drosophila melanogaster overexpressing CYP9A32 showed enhanced tolerance to emamectin benzoate. Homology modeling and molecular docking analyses revealed tight binding of CYP9A32 to emamectin benzoate. These findings demonstrate that CYP9A32 upregulation contributes to emamectin benzoate resistance in S. frugiperda. This study enhances our understanding of P450-mediated resistance mechanisms and provides insights for improving insecticide resistance management in pest control programs.

Comparative transcriptomics of naturally susceptible and resistant Trypanosoma cruzi strains in response to Benznidazole.

Spatio-temporal dynamics of deltamethrin resistance in Triatoma infestans: Challenges for chagas disease vector control in Argentina.

Disease resistance and genetic characteristics of genetically selected largemouth bass (Micropterus salmoides) revealed by whole genome resequencing.

Lolium multiflorum exhibits resistance to mesosulfuron-methyl through ALS mutations; HZ2 population also shows metabolic resistance through P450 pathways. Lolium multiflorum L., is a weed that frequently appears in wheat fields and is recognized for its strong competitive nature, where it can cause significant damage to grain production. The weeds of L. multiflorum in the wheat fields may have developed resistance to mesosulfuron-methyl. This study explored the response of L. multiflorum populations in certain areas of Henan Province, China, to mesosulfuron-methyl. The study found that, compared to the HX1 sensitive population, the HZ1 and HZ2 populations showed resistance to mesosulfuron-methyl in the full dose-response test, with resistance ratios of 12.38- and 24.19-fold, respectively. Genetic sequencing revealed novel mutations at the Pro-197-Thr and Asp-376-Glu residues of the ALS gene in both resistant populations. A critical finding was the divergent resistance mechanisms between the geographically close populations, with HZ1 resistance solely conferred by target-site mutations and HZ2 exhibiting multiple resistance driven by both target-site mutations and enhanced metabolism mediated by cytochrome P450 monooxygenases. This was conclusively demonstrated by applying the P450 inhibitors malathion and PBO, which reversed resistance in HZ2 by 66.77% and 70.53%, respectively. Furthermore, both resistant populations showed heightened sensitivity to isoproturon, suggesting a potential management strategy. Molecular docking simulations corroborated that the identified mutations reduce herbicide binding affinity. Our findings provide the first evidence of concurrent target-site and non-target-site resistance to mesosulfuron-methyl in Chinese L. multiflorum, offering crucial insights for diagnosing and managing herbicide resistance.

The recurrence of clinically advanced cancers is an evolutionary consequence of standard-of-care chemotherapies generally administered at maximum tolerated doses to kill as many cancer cells as possible. The inevitable appearance of resistance raises the possibility of shifting treatment goals from complete tumor eradication to long-term disease control. The latter approach is employed by adaptive therapy, which aims to inhibit the evolutionary dynamics governing the spread of resistant tumor phenotypes. Adaptive therapy changes focus from the cancer cells that are responsive to therapy to those that are resistant and ultimately govern outcome. This therapeutic approach retains a pool of sensitive cancer cells to compete with the therapy-resistant ones through dynamic dose modulation and/or timing. Thus, fluctuations of treatment-sensitive cells are used to control the resistant population and prolong tumor control with existing therapy agents. Here, we explore non-genetic mechanisms of resistance, including the protective role of the tumor stroma, the epithelial-to-mesenchymal transition, the overexpression of drug efflux pumps, and the extracellular vesicle-mediated transfer of them. These mechanisms can increase the size of the resistant population at the expense of the sensitive one, reducing the ability of adaptive therapy to force tumor evolution into controllable cycles.

The guts of animals and humans harbor diverse microbial communities that are regularly exposed to bacteria originating from food, water, and their surroundings. Species such as Escherichia coli are adept at colonizing multiple hosts, along with surviving in the environment. By encoding pathogenic traits and transmissible forms of antimicrobial resistance (AMR), E. coli can also pose a zoonotic risk. Our understanding of the factors that govern host residency is limited. Here, we used a chicken cecal fermentation model to study survival and the AMR transfer potential of 17 host-associated extended-spectrum β-lactamase (ESBL)-producing E. coli isolates. Vessels containing chicken cecal contents were stabilized for 4 days before the addition of a cocktail comprising ESBL-producing E. coli obtained from human, cattle, pig, and chicken hosts. Consecutive sampling showed that pig and cattle-associated isolates persisted in most vessels, although the recovery of all isolates declined over time. Increasing the inoculum dose or adding ceftiofur helped to stabilize populations of ESBL E. coli within the vessels, although this did not result in outgrowth of resistant populations in all vessels. Sequencing revealed that most new ESBL-producing E. coli recovered during the study acquired a blaCTX-M-1 plasmid from a single ESBL E. coli included in the cocktail that lacked host-specific traits (generalist). Our data highlight that isolate-specific differences in the E. coli genome composition likely explain the persistence of specific clones and efficiency of plasmid transfer, both of which could impact the spread of AMR in complex communities.IMPORTANCEThere are few insights into how host-associated Escherichia coli behave within the gut environment of other hosts. E. coli isolates that are immigrants to the gastrointestinal system of humans and animals have the potential to transfer their resistance to other native bacteria. A better understanding of this process is needed to assess how the gastrointestinal environment could serve as a reservoir and a melting pot of new, multidrug-resistant E. coli isolates.

Research into environmentally friendly methods for controlling nematodes in agricultural crops has gained significant momentum in recent years. This growing interest reflects a broader shift toward more ecologically responsible agricultural practices—ones that prioritize natural biological mechanisms, preserve soil fertility, and protect biodiversity. Increasing consumer demand for high-quality, chemical-free produce has further accelerated this transition. Among the many pests affecting crop production, phytoparasitic nematodes are some of the most destructive, particularly in vegetable crops, where they are responsible for substantial yield losses each year. Traditionally, synthetic pesticides have been the primary means of managing nematode infestations. However, their widespread use has led to considerable environmental concerns, including soil degradation, groundwater contamination, and harm to non-target organisms. Moreover, the effectiveness of many synthetic compounds diminishes over time due to soil interactions and the emergence of resistant nematode populations. Regulatory restrictions on soil fumigants—some of the few chemicals capable of penetrating deep into the soil—have also prompted the search for safer alternatives. As a result, research has increasingly focused on sustainable control strategies that integrate agronomic, biological, and natural solutions. Plant-based products, in particular, have shown considerable promise. These natural compounds exhibit strong nematicidal properties while maintaining a low environmental footprint. Their limited persistence in soil and low toxicity to humans, animals, and non-target plant species make them ideal candidates for sustainable pest management. Furthermore, the complex chemical makeup of plant-derived nematicides—often composed of multiple active ingredients—reduces the likelihood of nematodes developing resistance, a common issue with repeated synthetic pesticide applications. Numerous studies support the efficacy of these botanical alternatives. By preserving soil health and enhancing plant resilience, such approaches contribute not only to pest control but also to long-term agricultural sustainability and productivity.

Echinochloa crus-galli poses a significant challenge to rice production, with herbicide resistance threatening agricultural output in South China. We investigated quinclorac resistance in E. crus-galli populations in rice fields in the Hainan Province, identifying a metabolically resistant (R) population that exhibited faster metabolism compared with the susceptible (S) population. RNA-Seq revealed 18 differentially expressed genes (DEGs), including two of the P450 family, four glutathione S-transferases (GSTs), six glycosyltransferases (GTs), one ABC transporter, and one hydrolase, that were upregulated in the R biotype. Metabolomic analysis identified 28 differentially accumulated metabolites (DAMs) that were specifically enriched in the R biotype. Correlation analysis showed that the DEGs of EcUGT79-like and EcUGT13248-like were strongly positively correlated with most of the DAMs. Transgenic Arabidopsis and yeast expressing EcUGT79-like exhibited resistance to quinclorac and clopyralid, whereas the transgenic EcUGT13248-like biotype did not display resistance. Overall, EcUGT79-like is the primary functional gene conferring resistance to quinclorac in E. crus-galli.

Echinochloa crus-galli is a grass weed that infests rice fields and causes significant crop yield losses. In this study, we surveyed 15 resistant E. crus-galli populations collected from rice fields in Hubei Province, China, and investigated the resistance levels and target site resistance mechanisms to the acetolactate synthase (ALS) inhibitor penoxsulam. The results of whole-plant bioassay experiments revealed that 15 populations presented different levels of resistance to penoxsulam. The Trp-574-Leu mutation was detected in ten resistant populations, and the Pro-197-Leu mutation was detected in one resistant population. Additionally, the in vitro ALS activity in resistant populations (18-ETF, 18-WJJ, and 18-WMJ) was 51.28-, 5.51-, and 8.46-fold greater than that in the susceptible population. The ALS from these resistant populations requires a much higher penoxsulam concentration for activity inhibition. ALS gene expression in three resistant populations (18-ETF, 18-WJJ, and 18-WMJ) was 1.53-, 1.58-, and 1.41-fold greater than that in the susceptible population 18-NJ before penoxsulam treatment. Our results indicated that target-site mutation in ALS is at least partially responsible for barnyardgrass resistance to penoxsulam in Hubei Province.