Integrative analysis of co-expression pattern of solute carrier transporters reveals molecular subtypes associated with tumor microenvironment hallmarks and clinical outcomes in colon cancer.

Recent findings have suggested that solute carrier (SLC) transporters play an important role in tumor development and progression, and alterations in the expression of individual SLC genes are critical for fulfilling the heightened metabolic requirements of cancerous cells. However, the global influence of the co-expression pattern of SLC transporters on the clinical stratification and characteristics of the tumor microenvironment (TME) remains unexplored. In this study, we identified five SLC gene subtypes based on transcriptome co-expression patterns of 187 SLC transporters by consensus clustering analysis. These subtypes, which were characterized by distinct TME and biological characteristics, were successfully employed for prognostic and chemotherapy response prediction in colon cancer patients, as well as demonstrated associations with immunotherapy benefits. Then, we generated an SLC score model comprising 113 genes to quantify SLC gene co-expression patterns and validated it as an independent prognostic factor and drug response predictor in several independent colon cancer cohorts. Patients with a high SLC score possessed distinct characteristics of copy number variation, genomic mutations, DNA methylation, and indicated an SLC-S2 subtype, which was characterized by strong stromal cell infiltration, stromal pathway activation, poor prognosis, and low predicted fluorouracil and immunotherapeutic responses. Furthermore, the analysis of the Cancer Therapeutics Response Portal database revealed that inhibitors targeting PI3K catalytic subunits could serve as promising chemosensitizing agents for individuals exhibiting high SLC scores. In conclusion, the co-expression patterns of SLC transporters aided the disease classification, and the SLC score proved to be a reliable tool for distinguishing SLC gene subtypes and guiding precise treatment in patients with colon cancer.

Sublethal effect of chlorpyrifos on predatory behavior and physiology of Eocanthecona furcellata (Hemiptera: Pentatomidae).

Insecticides have been known to reduce the predation efficacy of natural enemies. However, the mechanism of the sublethal effect of insecticides on the functional response of predators remains unclear. This study investigated the sublethal effects of the broad-spectrum insecticide chlorpyrifos on the predatory bug Eocanthecona furcellata (Wolff), which is a potential biological control agent against pests in integrated pest management (IPM) programs. After exposure to a sublethal concentration of chlorpyrifos, the predation capacity and the maximum predatory number of E. furcellata increased by 11.27 and 15.26%, respectively, with prey handling time decreased by 15.07%, and the searching efficiency increased by 5.88-12.61%. Additionally, the intraspecific interference effect was enhanced. Glutathione S-transferase (GST) activity was significantly decreased after 12- to 60-h treatment. At 12 h after treatment, the expression levels of GST gene (GST3), acetylcholinesterase gene (AChE), and cytochrome P450 monooxygenasegene (cyp6B1) were significantly up-regulated by 1.47-, 1.48-, and 2.05-fold, respectively, while GST gene (GST1) was significantly down-regulated by 16.67-fold. These results indicated that a sublethal chlorpyrifos concentration inhibited the GST activity and stimulated the predatory behavior of E. furcellata. The results will advance our understanding of the toxicological mechanism of predatory stink bug responses to insecticides and predict chlorpyrifos' effects on predators in an IPM program.

A short neuropeptide F analog (sNPF), III-2 may particularly regulate juvenile hormone III to influence Spodoptera frugiperda metamorphosis and development.

Allatostatin (AS) or Allatotropin (AT) is a class of insect short neuropeptide F (sNPF) that affects insect growth and development by inhibiting or promote the synthesis of juvenile hormone (JH) in different insects. III-2 is a novel sNPF analog derived from a group of nitroaromatic groups connected by different amino acids. In this study, we found that III-2 showed high insecticidal activity against S. frugiperda larvae with a LC50 of 18.7 mg L-1. As demonstrated by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), III-2 particularly facilitated JH III and hindered 20E synthesis in S. frugiperda. The results of RNA-Seq and quantitative real-time polymerase chain reaction (qPCR) showed that III-2 treatment promoted the expression of key genes such as SfCYP15C1 in JH synthesis pathway and inhibited the expression of SfCYP314A1 and other genes in the 20E synthetic pathway. Significant differences were also observed in the expression of the genes related to cuticle formation. We report for the first time that sNPF compounds specifically interfere with the synthesis and secretion of a certain JH in insects, thus affecting the ecdysis and growth of insects, and leading to death. This study may provide a new plant conservation concept for us to seek the targeted control of certain insects based on specific interference with different JH.

Co-expression pattern of SLC transporter genes associated with the immune landscape and clinical outcomes in gastric cancer.

Solute carrier (SLC) transporters play a dual role in the occurrence and progression of tumours by acting as both suppressors and promoters. However, the overall impact of SLC transcriptome signatures on the tumour microenvironment, biological behaviour and clinical stratification of gastric cancer has not been thoroughly investigated. Therefore, we comprehensively analysed the expression profiles of the SLC transporter family members to identify novel molecular subtypes in gastric cancer. We identified two distinct SLC subtypes, SLC-S1 and SLC-S2, using non-negative matrix factorization. These subtypes were markedly linked with the tumour microenvironment landscape, biological pathway activation and distinct clinical features of gastric cancer. Furthermore, a new scoring model, the SLC score, was developed to quantify the SLC subtypes. High SLC scores indicated a pattern of 'SLC-S2', characterized by stromal infiltration and activation, poor prognosis and insensitivity to chemotherapy and immunotherapy, but high sensitivity to imatinib. The SLC score could serve as a supplement to the Tumour Node Metastasis (TNM) staging system to guide personalized treatment strategies and predict prognosis for patients with gastric cancer.

Multiple herbicide resistance in a Cyperus difformis population in rice field from China.

Herbicide resistance is rapidly emerging in Cyperus difformis in rice fields across China. The response of a C. difformis population GX-35 was tested against five acetolactate synthase (ALS)-inhibiting herbicides, auxin herbicide MCPA and photosynthesis II (PSII)-inhibitor bentazone. Population GX-35 evolved multiple resistance to ALS-inhibiting herbicides (penoxsulam, bispyribac­sodium, pyrazosulfuron-ethyl, halosulfuron-methly and imazapic) and auxin herbicide MCPA, with resistance levels of 140-, 1253-, 578-, 18-, 13-, and 21-fold, respectively, compared to the susceptible population. In this population, ALS gene expression was similar to that of the susceptible population. However, an Asp376Glu mutation in ALS gene was observed, leading to reduced inhibition of in-vitro ALS activities by five ALS-inhibiting herbicides. Furthermore, CYP71D8, CYP77A3, CYP78A5 and three ABC transporter genes (cluster-14412.23067, cluster-14412.25321, and cluster-14412.24716) over-expressed in absence of penoxsulam. On the other hand, an UGT73C1 and an ABC transporter (cluster-14412.25038) were induced by penoxsulam. Additionally, both over-expression and induction were observed for CYP74, CYP71A1, UGT88A1 and an ABC transporter (cluster-14412.21723). The GX-35 population has indeed evolved multiple herbicide resistance in China. Therefore, a diverse range of weed control tactics should be implemented in rice field.

Epigenetic Modification-Associated Molecular Classification of Gastric Cancer.

Epigenetic modification is involved in tumorigenesis and cancer progression. We developed an epigenetic modification-associated molecular classification of gastric cancer (GC) to identify signature genes that accurately predict prognosis and the efficacy of immunotherapy. Least absolute shrinkage and selection operator and multivariate Cox regression analysis were conducted to develop an epigenetic modification-associated molecular classification. We investigated the significance of PIP4P2, an independent prognostic factor of the classification system, in predicting the prognosis and immunotherapy efficacy of patients with GC. The epigenetic modification-associated molecular classification was highly associated with the clinicopathological characteristics of patients and the existing classification of GC. PIP4P2 was highly expressed in GC tissue and tumor-associated macrophages. High PIP4P2 expression in GC tissue-induced tumor progression by activating PI3K/AKT signal transduction had a negative impact on immunotherapy efficacy. High expression of PIP4P2 in macrophages was correlated with poor prognosis in patients with GC. PIP4P2 is an independent unfavorable prognostic factor of epigenetic modification-associated molecular classification, is involved in tumorigenic progression, and is essential for assessing the prognosis and immunotherapy efficacy of GC.

Colonization Mechanism of Endophytic Enterobacter cloacae TMX-6 on Rice Seedlings Mediated by Organic Acids Exudated from Roots.

Small molecular organic acids (SMOAs) in root exudates are critical for plant-microbe interaction, especially under environmental stresses. However, the dominant organic acids driving the process and promoting the colonization are unclear. Here, using a target metabolomics, 20 main SMOAs of rice root exudates were identified and analyzed in control and 10 mg/L thiamethoxam-treated groups. The composition of these SMOAs differed significantly between the two treatments. Among which, malic acid, citric acid, succinic acid, and proline induced a chemotactic response, swimming ability, and biofilm formation of Enterobacter cloacae TMX-6 in a dose-dependent manner. The maximal chemotactic response of TMX-6 was induced by proline at 10 mg/L, and a strong chemotactic response was even observed at 0.01 mg/L. The recruitment assay confirmed that the addition of these four compounds promoted the colonization of TMX-6. The results provide insight for directional regulation of plant-microbe interactions for beneficial outcomes.

HCN-induced embryo arrest: passion fruit as an ecological trap for fruit flies.

BACKGROUND: Fruit flies are important economic pests of fruits, vegetables, and nuts all over the world. In this study, a permanent ecological trap, which was created by the ovicidal effect of phytogenic hydrogen cyanide (HCN) liberated from passion fruits due to oviposition by fruit flies and can be used in the pest management, were determined. RESULTS: Observation of fruit fly eggs in Passiflora within the passion fruit cultivation region in southern China, from Aug 2019 to Oct 2020 showed that the exotic Passiflora attracted the native fruit flies to oviposit, but the eggs could not hatch. Using classical staging to categorize embryonic development and fumigation assays, we show that oviposition by fruit fly on passion fruits, release HCN from the cyanogenic mesocarp. Exposure of the eggs to HCN causes arrest of embryonic development and finally the death of eggs. CONCLUSION: Our results reveal that the life cycle of fruit fly in Passiflora is interrupted at the egg stage. Consequently, we predict that this ecological trap may be permanent. Extensive cultivation of the Passiflora vine as a dead-end trap crop may be an effective avenue to reduce populations of fruit fly pests. © 2023 Society of Chemical Industry.

N6-methyladenosine RNA Methylation Correlates with Immune Microenvironment and Immunotherapy Response of Melanoma.

RNA methylation normally inhibits the self-recognition and immunogenicity of RNA. As such, it is likely an important inhibitor of cancer immune recognition in the tumor microenvironment, but how N6-methyladenosine (m6A) affects prognosis and treatment response remains unknown. In eight independent melanoma cohorts (1,564 patients), the modification patterns of 21 m6A gene signatures were systematically correlated with the immune cell infiltration of melanoma tumor microenvironment. m6A modification patterns for each patient were quantified using the principal component analysis method, yielding an m6Ascore that reflects the abundance of m6A RNA modifications. Two different m6A modification patterns were observed in patients with melanoma, separated into high and low m6Ascores that correlated with survival and treatment response. Low m6Ascores were characterized by an immune-inflamed phenotype, with 61.1% 5-year survival. High m6Ascores were characterized by an immune-excluded phenotype, with 52.2% 5-year survival. Importantly, lower m6Ascores correlated with more sensitive anti-PD-1 and anti-CTLA4 treatment responses, with 90% of patients with low m6Ascore responding, whereas 10% of those with high m6Ascore nonresponding (in cohort GSE63557). At single-cell and spatial transcriptome resolution, m6Ascore reflects melanoma malignant progression, immune exhaustion, and resistance to immune checkpoint blockade therapy. Hence, the m6Ascore correlates to an important facet of tumor immune escape as a tool for personalized medicine to guide immunotherapy in patients with melanoma.

Commensal microbiome promotes hair follicle regeneration by inducing keratinocyte HIF-1α signaling and glutamine metabolism.

Tissue injury induces metabolic changes in stem cells, which likely modulate regeneration. Using a model of organ regeneration called wound-induced hair follicle neogenesis (WIHN), we identified skin-resident bacteria as key modulators of keratinocyte metabolism, demonstrating a positive correlation between bacterial load, glutamine metabolism, and regeneration. Specifically, through comprehensive multiomic analysis and single-cell RNA sequencing in murine skin, we show that bacterially induced hypoxia drives increased glutamine metabolism in keratinocytes with attendant enhancement of skin and hair follicle regeneration. In human skin wounds, topical broad-spectrum antibiotics inhibit glutamine production and are partially responsible for reduced healing. These findings reveal a conserved and coherent physiologic context in which bacterially induced metabolic changes improve the tolerance of stem cells to damage and enhance regenerative capacity. This unexpected proregenerative modulation of metabolism by the skin microbiome in both mice and humans suggests important methods for enhancing regeneration after injury.

Expression pattern of secretory-cell-related transcriptional signatures in colon adenocarcinomas defines tumor microenvironment characteristics and correlates with clinical outcomes.

Despite the connection of secretory cells to distinct mucus-containing colon cancer histological subtypes and the interaction of secretory cells with immune cells in the pathogenesis of intestinal inflammatory diseases, whether the secretory cell signatures are associated with tumor microenvironment (TME) heterogeneity and can aid in colon cancer patient classification have not been investigated. Here, by performing the principal component analysis and consensus clustering analysis, we identified four distinct expression patterns based on secretory cell signatures which were significantly associated with different clinical behaviors, TME landscape, pathway activation, genomic mutations, and DNA methylation characteristics. Subsequently, a 'SCS score' model was constructed. The high SCS score indicated a pattern of 'secretory cell subtype 2', which was characterized by stromal infiltration and activation, and predicted poor prognosis and low sensitivity to fluorouracil-based chemotherapy and immunotherapy, but high sensitivity to PI3K catalytic subunit inhibitors. In conclusion, our study comprehensively uncovered the tumor heterogeneity related to secretory cell signature expression patterns. Moreover, the SCS score can supplement routine histopathological assessments to guide personalized therapeutic strategies in colon cancer patients.

High aquaporin expression correlates with increased translocation of quinclorac from shoots to roots in resistant Echinochloa crus-galli var. zelayensis.

BACKGROUND: Echinochloa crus-galli var. zelayensis is a troublesome weed in rice fields and can be controlled by using quinclorac. However, over-reliance on quinclorac has resulted in resistant (R) barnyardgrass, which differs significantly in its ability to transport quinclorac compared to susceptible (S) barnyardgrass. This study aimed to investigate the underlying mechanisms for this different translocation between R and S barnyardgrass. RESULTS: Larger amount of quinclorac was transferred from shoots to roots in R compared to S barnyardgrass. After 1 day of quinclorac [300 g active ingredient (a.i.) ha-1 ] foliar treatment, its content in shoots of R was 81.92% of that in S barnyardgrass; correspondingly, in roots of R was 1.17 fold of that in S barnyardgrass. RNA-sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) confirmed the expression levels of PIPs belonging to aquaporins (AQPs) in R were higher than in S barnyardgrass, with or without quinclorac treatment. With co-application of quinclorac and AQPs inhibitors [mercury(II) chloride (HgCl2 )] treatment, even though the expression levels of PIPs and the transport rates of quinclorac were both suppressed in R and S barnyardgrass, this process was less pronounced in R than in S barnyardgrass. CONCLUSION: This report provides clear evidence that higher PIPs expression results in rapid quinclorac translocation from shoots to roots and reduces the quinclorac accumulation in the shoot meristems in R barnyardgrass, thus reducing the control efficacy of quinclorac. © 2022 Society of Chemical Industry.

CD8+ T cell/cancer-associated fibroblast ratio stratifies prognostic and predictive responses to immunotherapy across multiple cancer types.

Background: Cancer-associated fibroblasts (CAFs) within the tumor microenvironment (TME) are critical for immune suppression by restricting immune cell infiltration in the tumor stromal zones from penetrating tumor islands and changing their function status, particularly for CD8+ T cells. However, assessing and quantifying the impact of CAFs on immune cells and investigating how this impact is related to clinical outcomes, especially the efficacy of immunotherapy, remain unclear. Materials and methods: The TME was characterized using immunohistochemical (IHC) analysis using a large-scale sample size of gene expression profiles. The CD8+ T cell/CAF ratio (CFR) association with survival was investigated in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) lung cancer cohorts. The correlation between CFR and immunotherapeutic efficacy was computed in five independent cohorts. The correlation between CFR and objective response rates (ORRs) following pembrolizumab monotherapy was investigated in 20 solid tumor types. To facilitate clinical translation, the IHC-detected CD8/α-SMA ratio was applied as an immunotherapeutic predictive biomarker in a real-world lung cancer cohort. Results: Compared with normal tissue, CAFs were enriched in cancer tissue, and the amount of CAFs was overwhelmingly higher than that in other immune cells. CAFs are positively correlated with the extent of immune infiltration. A higher CFR was strongly associated with improved survival in lung cancer, melanoma, and urothelial cancer immunotherapy cohorts. Within most cohorts, there was no clear evidence for an association between CFR and programmed death-ligand 1 (PD-L1) or tumor mutational burden (TMB). Compared with TMB and PD-L1, a higher correlation coefficient was observed between CFR and the ORR following pembrolizumab monotherapy in 20 solid tumor types (Spearman's r = 0.69 vs. 0.44 and 0.21). In a real-world cohort, patients with a high CFR detected by IHC benefited considerably from immunotherapy as compared with those with a low CFR (hazard ratio, 0.37; 95% confidence interval, 0.19-0.75; p < 0.001). Conclusions: CFR is a newly found and simple parameter that can be used for identifying patients unlikely to benefit from immunotherapy. Future studies are needed to confirm this finding.

Characterization and genomic analysis of a bensulfuron methyl-degrading endophytic bacterium Proteus sp. CD3 isolated from barnyard grass (Echinochloa crus-galli).

Bensulfuron methyl (BSM) is a widely used sulfonylurea herbicide in agriculture. However, the large-scale BSM application causes severe environmental problems. Biodegradation is an important way to remove BSM residue. In this study, an endophytic bacterium strain CD3, newly isolated from barnyard grass (Echinochloa crus-galli), could effectively degrade BSM in mineral salt medium. The strain CD3 was identified as Proteus sp. based on the phenotypic features, physiological biochemical characteristics, and 16S rRNA gene sequence. The suitable conditions for BSM degradation by this strain were 20-40°C, pH 6-8, the initial concertation of 12.5-200 mg L-1 with 10 g L-1 glucose as additional carbon source. The endophyte was capable of degrading above 98% BSM within 7 d under the optimal degrading conditions. Furthermore, strain CD3 could also effectively degrade other sulfonylurea herbicides including nicosulfuron, halosulfuron methyl, pyrazosulfuron, and ethoxysulfuron. Extracellular enzyme played a critical role on the BSM degradation by strain CD3. Two degrading metabolites were detected and identified by using liquid chromatography-mass spectrometry (LC-MS). The biochemical degradation pathways of BSM by this endophyte were proposed. The genomic analysis of strain CD3 revealed the presence of putative hydrolase or esterase genes involved in BSM degradation, suggesting that a novel degradation enzyme for BSM was present in this BSM-degrading Proteus sp. CD3. The results of this research suggested that strain CD3 may have potential for using in the bioremediation of BSM-contaminated environment.

Bruceine D may affect the phenylpropanoid biosynthesis by acting on ADTs thus inhibiting Bidens pilosa L. seed germination.

Bruceine D is a natural quassinoid, which was successfully isolated in our research group from the residue of Brucea javanica (L.) seeds. Our previous research showed that Bruceine D prevented Bidens pilosa L. seed germination by suppressing the activity of key enzymes and the expression levels of key genes involved in the phenylpropanoid biosynthesis pathway. In this study, integrated analyses of non-targeted metabolomic and transcriptomic were performed. A total of 356 different accumulated metabolites (DAMs) were identified, and KEGG pathway analyses revealed that most of these DAMs were involved in phenylpropanoid biosynthesis. The decreased expression of ADTs and content of L-phenylalanine implicates that Bruceine D may suppress the downstream phenylpropanoid biosynthesis pathway by disrupting primary metabolism, that is, the phenylalanine biosynthesis pathway, thus inhibiting the final products, resulting in the interruption of B. pilosa seed germination. These results suggest that Bruceine D may inhibit the B. pilosa seed germination by suppressing phenylpropanoid biosynthesis through acting on ADTs.

Cyperus rotundus L. drives arable soil infertile by changing the structure of soil bacteria in the rhizosphere, using a maize field as an example.

Rhizosphere microorganisms can greatly affect plant growth, especially the plant growth-promoting rhizobacteria (PGPR), which can improve plant root development and growth because they contain various biological functions including nitrogen fixation, phosphate solubilization, and phytosiderophore production. This study demonstrates that Cyperus rotundus L. is capable of developing and forming complex underground reproductive systems at arbitrary burial depths and cutting modes due to its extremely strong multiplication and regeneration ability. With the densities of C. rotundus increasing, the abundance of PGPR, soil enzymes invertase and urease, the nutrient contents of the field soil, and maize quality were impacted. Notably, more abundance of PGPR-most notably, the nitrogen-fixing microorganisms (NFMs) such as Azospirillum, Burkholderia, Mycobacterium, and Rhizobium-enriches in the rhizosphere of C. rotundus than in that of maize. In addition, the activities of soil enzymes invertase (S_SC) and urease (S_SU) were significantly higher in its rhizosphere than in maize, further proving that more NFMs enrich the C. rotundus rhizosphere. The nutrient contents of the field soil of TN, SOM, and SOC were reduced, indicating that the presence of C. rotundus made the soil infertile. Hence, these pieces of evidence indicate that C. rotundus may drive the field soil infertile as reflected by reduced soil nutrients via altering rhizosphere bacteria community structure.

Tumor Microenvironment Evaluation for Gastrointestinal Cancer in the Era of Immunotherapy and Machine Learning.

A dynamic and mutualistic interplay between tumor cells and the surrounding tumor microenvironment (TME) triggered the initiation, progression, metastasis, and therapy response of solid tumors. Recent clinical breakthroughs in immunotherapy for gastrointestinal cancer conferred considerable attention to the estimation of TME, and the maturity of next-generation sequencing (NGS)-based technology contributed to the availability of increasing datasets and computational toolbox for deciphering TME compartments. In the current review, we demonstrated the components of TME, multiple methodologies involved in TME detection, and prognostic and predictive TME signatures derived from corresponding methods for gastrointestinal cancer. The TME evaluation comprises traditional, radiomics, and NGS-based high-throughput methodologies, and the computational algorithms are comprehensively discussed. Moreover, we systemically elucidated the existing TME-relevant signatures in the prognostic, chemotherapeutic, and immunotherapeutic settings. Collectively, we highlighted the clinical and technological advances in TME estimation for clinical translation and anticipated that TME-associated biomarkers may be promising in optimizing the future precision treatment for gastrointestinal cancer.

Evaluation of stromal cell infiltration in the tumor microenvironment enable prediction of treatment sensitivity and prognosis in colon cancer.

Current clinical factors for screening candidates that might benefit from adjuvant chemotherapy in colon cancer are inadequate. Tumor microenvironment, especially the stromal components, has the potential to determine treatment response. However, clinical translation of the tumor-associated stromal characterization into a practical biomarker for helping treatment decision has not been established. Using machine learning, we established a novel 31-gene signature, called stromal cell infiltration intensity score (SIIS), to distinguish patients characterized by the enrichment of abundant stromal cells in five colon cancer datasets from GEO (N = 990). Patients with high-SIIS were at higher risk for recurrence and mortality, and could not benefit from adjuvant chemotherapy due to their intrinsic drug resistance; however, the opposite was reported for patients with low-SIIS. The role of SIIS in detection of patients with high stromal cell infiltration and reduced drug efficiency was consistently validated in the TCGA-COAD cohort (N = 382), Sun Yat-sen University Cancer Center cohort (N = 30), and could also be observed in TCGA pan-cancer settings (N = 4898) and four independent immunotherapy cohorts (N = 467). Based on multi-omics data analysis and the CRISPR library screen, we reported that lack of gene mutation, hypomethylation in ADCY4 promoter region, activation of WNT-PCP pathway and SIAH2-GPX3 axis were potential mechanisms responsible for the chemoresistance of patients within high-SIIS group. Our findings demonstrated that SIIS provide an important reference for those making treatment decisions for such special patients.

Assessing the toxicological interaction effects of imidacloprid, thiamethoxam, and chlorpyrifos on Bombus terrestris based on the combination index.

In modern agricultural production, a variety of pesticides are widely used to protect crops against pests. However, extensive residues of these pesticides in the soil, water, and pollen have negatively affected the health of nontarget organisms, especially among pollinators such as bumblebees. As an important pollinator, the bumblebee plays a vital role in agricultural production and the maintenance of ecosystem diversity. Previous research has focused on the effects of a single pesticide on pollinating insects; however, the synergistic effects of multiple agents on bumblebees have been not studied in detail. Imidacloprid, thiamethoxam, and chlorpyrifos are three of common pesticides known for severe effects on bumblebee health. It is still unknown what synergistic effects of these pesticides on pollinators. In our test, the individual and combined toxicities of chlorpyrifos, thiamethoxam, and imidacloprid to bumblebees after 48 h of oral administration were documented by the equivalent linear equation method. Our results showed that the toxicity of each single pesticide exposure, from high to low, was imidacloprid, thiamethoxam, and chlorpyrifos. All binary and ternary combinations showed synergistic or additive effects. Therefore, our research not only shows that the mixed toxicity of insecticides has a significant effect on bumblebees, but also provides scientific guidelines for assessing the safety risks to bumblebees of these three insecticide compounds. In assessing the risk to pollinating insects, the toxicity levels of laboratory experiments are much lower than the actual toxicity in the field.

Corrigendum: PET/Ct Imaging of Activated Cancer-Associated Fibroblasts Predict Response to PD-1 Blockade in Gastric Cancer Patients.

[This corrects the article DOI: 10.3389/fonc.2021.802257.].