PrismNet: predicting protein-RNA interaction using in vivo RNA structural information.

Fundamental to post-transcriptional regulation, the in vivo binding of RNA binding proteins (RBPs) on their RNA targets heavily depends on RNA structures. To date, most methods for RBP-RNA interaction prediction are based on RNA structures predicted from sequences, which do not consider the various intracellular environments and thus cannot predict cell type-specific RBP-RNA interactions. Here, we present a web server PrismNet that uses a deep learning tool to integrate in vivo RNA secondary structures measured by icSHAPE experiments with RBP binding site information from UV cross-linking and immunoprecipitation in the same cell lines to predict cell type-specific RBP-RNA interactions. Taking an RBP and an RNA region with sequential and structural information as input ('Sequence & Structure' mode), PrismNet outputs the binding probability of the RBP and this RNA region, together with a saliency map and a sequence-structure integrative motif. The web server is freely available at http://prismnetweb.zhanglab.net.

Recent advances in RNA structurome.

RNA structures are essential to support RNA functions and regulation in various biological processes. Recently, a range of novel technologies have been developed to decode genome-wide RNA structures and novel modes of functionality across a wide range of species. In this review, we summarize key strategies for probing the RNA structurome and discuss the pros and cons of representative technologies. In particular, these new technologies have been applied to dissect the structural landscape of the SARS-CoV-2 RNA genome. We also summarize the functionalities of RNA structures discovered in different regulatory layers-including RNA processing, transport, localization, and mRNA translation-across viruses, bacteria, animals, and plants. We review many versatile RNA structural elements in the context of different physiological and pathological processes (e.g., cell differentiation, stress response, and viral replication). Finally, we discuss future prospects for RNA structural studies to map the RNA structurome at higher resolution and at the single-molecule and single-cell level, and to decipher novel modes of RNA structures and functions for innovative applications.

An ultra low-input method for global RNA structure probing uncovers Regnase-1-mediated regulation in macrophages.

To enable diverse functions and precise regulation, an RNA sequence often folds into complex yet distinct structures in different cellular states. Probing RNA in its native environment is essential to uncovering RNA structures of biological contexts. However, current methods generally require large amounts of input RNA and are challenging for physiologically relevant use. Here, we report smartSHAPE, a new RNA structure probing method that requires very low amounts of RNA input due to the largely reduced artefact of probing signals and increased efficiency of library construction. Using smartSHAPE, we showcased the profiling of the RNA structure landscape of mouse intestinal macrophages upon inflammation, and provided evidence that RNA conformational changes regulate immune responses. These results demonstrate that smartSHAPE can greatly expand the scope of RNA structure-based investigations in practical biological systems, and also provide a research paradigm for the study of post-transcriptional regulation.

Quantification of Cross-Contamination of Campylobacter jejuni during Food Preparation in a Model Kitchen in China.

ABSTRACT: Numerous outbreak investigations and case-control studies of campylobacteriosis have provided evidence that handling Campylobacter-contaminated chicken products is a high risk factor for infection and illness. In this study, the cross-contamination and transfer rates of Campylobacter jejuni from chicken to ready-to-eat food were determined in various food handling scenarios. Skinless raw chicken breasts were artificially contaminated with C. jejuni and diced on cutting boards of three different materials. Whether cold water, cold water with detergent, or hot water was used, statistically significant differences were found between the transfer rates of C. jejuni to unwashed and washed cutting boards or hands, respectively. When both kitchen knife and cutting board were reused after dicing the artificially contaminated chicken, the transfer rates of C. jejuni to cucumber cut on bamboo, wooden, and plastic cutting boards were 16.28, 12.82, and 5.32%, respectively. The transfer rates from chicken to bread, a large lift-up water faucet handle, and a small twist faucet handle via unwashed hands were 0.49, 4.64, and 3.14%, respectively. This research provides scientific evidence that various types of contaminated kitchenware and cook's hands are vital potential vehicles for the cross-contamination of Campylobacter from raw chicken to ready-to-eat food and emphasizes the importance of timely and proper cleaning to prevent cross-contamination during food handling; therefore, high-quality consumer education to reduce the risk of foodborne infection is urgent and necessary.

Prenatal Stress Impairs Postnatal Learning and Memory Development via Disturbance of the cGMP-PKG Pathway and Oxidative Phosphorylation in the Hippocampus of Rats.

Clinical and animal studies have found that prenatal stress can lead to pathological changes in embryos and fetuses. However, the mechanisms through which this occurs have not been made clear. In the present study, pregnant rats were subjected to chronic psychological stress during gestational days using an improved communication box system, and the changes in behavioral performance and proteins in the hippocampus of offspring were analyzed. It was found that prenatal stress caused postnatal growth retardation and impairment in spatial learning and memory. Furthermore, in isobaric tags for relative and absolute quantitation-based proteomics analyses, 158 significantly differentially expressed proteins (DEPs) were found between the two groups. Further analyses showed that these DEPs are involved in different molecular function categories and participate in several biological processes, such as energy metabolism, learning or memory, and synaptic plasticity. Moreover, the enrichment of pathways showed that the learning and memory impairment was primarily connected with the cyclic guanosine monophosphate-protein kinase G (cGMP-PKG) pathway and oxidative phosphorylation. At the same time, the cGMP level and the expression of PKG protein were significantly decreased, and the neuronal mitochondria appeared to have a swollen and irregular shape in the hippocampus of offspring of stressed rats. These results suggest that the chronic psychological stress that pregnant rats were subjected to during gestational days may have impaired the spatial learning and memory of offspring. This affected the hippocampal oxidative phosphorylation and inhibited the cGMP-PKG pathway.

Characterization and quantitative trait locus mapping of late-flowering from a Thai soybean cultivar introduced into a photoperiod-insensitive genetic background.

The timing of both flowering and maturation determine crop adaptability and productivity. Soybean (Glycine max) is cultivated across a wide range of latitudes. The molecular-genetic mechanisms for flowering in soybean have been determined for photoperiodic responses to long days (LDs), but remain only partially determined for the delay of flowering under short-day conditions, an adaptive trait of cultivars grown in lower latitudes. Here, we characterized the late-flowering (LF) habit introduced from the Thai cultivar K3 into a photoperiod-insensitive genetic background under different photo-thermal conditions, and we analyzed the genetic basis using quantitative trait locus (QTL) mapping. The LF habit resulted from a basic difference in the floral induction activity and from the suppression of flowering, which was caused by red light-enriched LD lengths and higher temperatures, during which FLOWERING LOCUS T (FT) orthologs, FT2a and FT5a, were strongly down-regulated. QTL mapping using gene-specific markers for flowering genes E2, FT2a and FT5a and 829 single nucleotide polymorphisms obtained from restriction-site associated DNA sequencing detected three QTLs controlling the LF habit. Of these, a QTL harboring FT2a exhibited large and stable effects under all the conditions tested. A resequencing analysis detected a nonsynonymous substitution in exon 4 of FT2a from K3, which converted the glycine conserved in FT-like proteins to the aspartic acid conserved in TERMINAL FLOWER 1-like proteins (floral repressors), suggesting a functional depression in the FT2a protein from K3. The effects of the remaining two QTLs, likely corresponding to E2 and FT5a, were environment dependent. Thus, the LF habit from K3 may be caused by the functional depression of FT2a and the down-regulation of two FT genes by red light-enriched LD conditions and high temperatures.

Functional divergence between soybean FLOWERING LOCUS T orthologues FT2a and FT5a in post-flowering stem growth.

Genes in the FLOWERING LOCUS T (FT) family integrate external and internal signals to control various aspects of plant development. In soybean (Glycine max), FT2a and FT5a play a major role in floral induction, but their roles in post-flowering reproductive development remain undetermined. Ectopic overexpression analyses revealed that FT2a and FT5a similarly induced flowering, but FT5a was markedly more effective than FT2a for the post-flowering termination of stem growth. The down-regulation of Dt1, a soybean orthologue of Arabidopsis TERMINAL FLOWER1, in shoot apices in early growing stages of FT5a-overexpressing plants was concomitant with highly up-regulated expression of APETALA1 orthologues. The Dt2 gene, a repressor of Dt1, was up-regulated similarly by the overexpression of FT2a and FT5a, suggesting that it was not involved in the control of stem termination by FT5a. In addition to the previously reported interaction with FDL19, a homologue of the Arabidopsis bZIP protein FD, both FT2a and FT5a interacted with FDL12, but only FT5a interacted with FDL06. Our results suggest that FT2a and FT5a have different functions in the control of post-flowering stem growth. A specific interaction of FT5a with FDL06 may play a key role in determining post-flowering stem growth in soybean.

Estimated assessment of cumulative dietary exposure to organophosphorus residues from tea infusion in China.

BACKGROUND: China has the world's largest tea plantation area in the world. To sustain high yields of the tea, multiple pesticides are used on tea crops to control pests. Organophosphorus (OP) pesticides are among the most widely used types of agricultural pesticides in China. As tea is a significant potential source of exposure to pesticide residues, the public concern has increased in relation to pesticide residues found in tea in China. The aim of the study was to estimate cumulative dietary exposure to OP residues from tea infusion for Chinese tea consumers to determine whether exposure to OP residues from tea infusion is a cause of health concern for tea consumers in China. METHODS: OP residue data were obtained from the China National Monitoring Program on Food Safety (2013-2014), encompassing 1687 tea samples from 12 provinces. Tea consumption data were obtained from the China National Nutrient and Health Survey (2002), comprising 506 tea consumers aged 15-82 years. The transfer rates of residues from tea leaves into tea infusions were obtained from the literature. The relative potency factor (RPF) approach was used to estimate acute cumulative exposure to 20 OP residues from tea infusion using methamidophos as the index compound. Dietary exposure was calculated in a probabilistic way. RESULTS: For tea consumers, the mean and the 99.9th percentile (P99.9) of cumulative dietary exposure to OP residues from tea infusion equalled 0.08 and 1.08 µg/kg bw/d. When compared with the acute reference dose (ARfD), 10 µg/kg bw/d for methamidophos, this accounts for 0.8 and 10.8% of the ARfD. CONCLUSIONS: Even when considering OP residues from vegetables, fruits and other foods, there are no health concerns based on acute dietary exposure to OP residues from tea infusion. However, it is necessary to strengthen the management of the OP pesticides used on tea in China to reduce the risk of chronic dietary exposure to OPs from tea infusion.

Loss of Function of the E1-Like-b Gene Associates With Early Flowering Under Long-Day Conditions in Soybean.

Photoperiod response of flowering determines plant adaptation to different latitudes. Soybean, a short-day plant, has gained the ability to flower under long-day conditions during the growing season at higher latitudes, mainly through dysfunction of phytochrome A genes (E3 and E4) and the floral repressor E1. In this study, we identified a novel molecular genetic basis of photoperiod insensitivity in Far-Eastern Russian soybean cultivars. By testcrossing these cultivars with a Canadian cultivar Harosoy near-isogenic line for a recessive e3 allele, followed by association tests and fine mapping, we determined that the insensitivity was inherited as a single recessive gene located in an 842-kb interval in the pericentromeric region of chromosome 4, where E1-Like b (E1Lb), a homoeolog of E1, is located. Sequencing analysis detected a single-nucleotide deletion in the coding sequence of the gene in insensitive cultivars, which generated a premature stop codon. Near-isogenic lines (NILs) for the loss-of-function allele (designated e1lb) exhibited upregulated expression of soybean FLOWERING LOCUS T (FT) orthologs, FT2a and FT5a, and flowered earlier than those for E1Lb under long-day conditions in both the e3/E4 and E3/E4 genetic backgrounds. These NILs further lacked the inhibitory effect on flowering by far-red light-enriched long-day conditions, which is mediated by E4, but not that of red-light-enriched long-day conditions, which is mediated by E3. These findings suggest that E1Lb retards flowering under long-day conditions by repressing the expression of FT2a and FT5a independently of E1. This loss-of-function allele can be used as a new resource in breeding of photoperiod-insensitive cultivars, and may improve our understanding of the function of the E1 family genes in the photoperiod responses of flowering in soybean.

Distribution and Antimicrobial Susceptibility of Foodborne Salmonella Serovars in Eight Provinces in China from 2007 to 2012 (Except 2009).

One thousand four hundred ninety-one Salmonella isolates recovered from retail foods including chicken, beef, fish, pork, dumplings, and cold dishes in China in 2007, 2008, 2010, 2011, and 2012 were analyzed for distribution of serotype and antimicrobial susceptibility. A total of 129 Salmonella serotypes were detected among 1491 isolates. Salmonella Enteritidis (21.5%), Typhimurium (11.0%), Indiana (10.8%), Thompson (5.4%), Derby (5.1%), Agona (3.8%), and Shubra (3.0%) were the seven most important serotypes in 1491 isolates. For antibiotic susceptibility, except 16 (1.1%) isolates were susceptible to all tested antibiotics, 131 (8.8%) resisted 1-2 and 1344 (90.1%) resisted three or more antibiotics. One thousand forty-six (70.2%) of 1491 Salmonella isolates were identified as multidrug-resistant (MDR) isolates, which could resist three or more categories of antibiotics. Resistance to sulfisoxazole (78.1%) was most common among the tested Salmonella, followed by tetracycline (70.6%), trimethoprim/sulfamethoxazole (68.0%), and nalidixic acid (63.4%). Resistances to amikacin (20.0%), levofloxacin (18.7%), gatifloxacin (17.9%), ceftriaxone (17.7%), and cefoxitin (13.2%) were less frequently detected. Resistance to fluoroquinolones was most common among Salmonella Shubra and Indiana isolates, while resistance to cephalosporins was frequently detected among Salmonella Thompson isolates. The results highlighted the diversity of Salmonella serotypes and the high prevalence of Salmonella MDR isolates in China. Compared with Salmonella Enteritidis and Typhimurium isolates, the higher fluoroquinolones and cephalosporins resistance rates of some individual serotypes (Salmonella Shubra, Indiana, and Thompson) also provided more information for further study related to fluoroquinolones or cephalosporin-resistant Salmonella.

Role of C/EBP homologous protein and endoplasmic reticulum stress in asthma exacerbation by regulating the IL-4/signal transducer and activator of transcription 6/transcription factor EC/IL-4 receptor α positive feedback loop in M2 macrophages.

BACKGROUND: C/EBP homologous protein (Chop), a marker of endoplasmic reticulum (ER) stress, exhibits aberrant expression patterns during asthma development. However, its exact role in asthma pathogenesis is not fully understood. OBJECTIVES: We aimed to determine the function and mechanism of Chop in the pathogenesis of allergic asthma in patients and animals. METHODS: Studies were conducted in asthmatic patients and Chop-/- mice to dissect the role of Chop and ER stress in asthma pathogenesis. An ovalbumin (OVA)-induced allergic airway inflammation model was used to address the effect of Chop deficiency on asthma development. Next, the effect of Chop deficiency on macrophage polarization and related signaling pathways was investigated to demonstrate the underlying mechanisms. RESULTS: Asthmatic patients and mice after OVA induction exhibited aberrant Chop expression along with ER stress. Specifically, Chop was noted to be specifically overexpressed in macrophages, and mice deficient in Chop were protected from OVA-induced allergic airway inflammation, as manifested by attenuated airway inflammation, remodeling, and hyperresponsiveness. Chop was found to exacerbate allergic airway inflammation by enhancing M2 programming in macrophages. Mechanistic studies characterized an IL-4/signal transducer and activator of transcription 6/transcription factor EC (Tfec)/IL-4 receptor α positive feedback regulatory loop, in which IL-4 induces Chop expression, which then promotes signal transducer and activator of transcription 6 signaling to transcribe Tfec expression. Finally, Tfec transcribes IL-4 receptor α expression to promote M2 programming in macrophages. CONCLUSIONS: Chop and ER stress are implicated in asthma pathogenesis, which involves regulation of M2 programming in macrophages.

Risk assessment of dietary exposure to aluminium in the Chinese population.

In order to address the issue of excessive intake of aluminium (Al) from Al-containing food additives in the Chinese diet, this study conducted a dietary exposure assessment of Al in the general population based on the national surveillance data of Al content in foods and national food consumption data. It was found that the mean dietary exposure of the whole Chinese population to Al from Al-containing food additives was 1.795 mg kg‒1 bw week‒1, not exceeding the PTWI, while high dietary exposures (e.g., 97.5th percentile) to Al were 7.660 and 2.103-2.903 mg kg‒1 bw week‒1 for children, respectively, both exceeding the PTWI. It was found that the dietary exposure to Al for 32.5% of the total Chinese population and 42.6% of children aged 4-6 years exceeded the PTWI. Wheat flour and wheat-based products are the main source of dietary A l exposure (85% of the total intake); and puffed foods are the major source of Al intake for children. These findings suggested that consumption of Al-containing food additives could be a health concern for consumers with high food consumption (97.5th percentile) and children under the age of 14 years.

A soybean quantitative trait locus that promotes flowering under long days is identified as FT5a, a FLOWERING LOCUS T ortholog.

FLOWERING LOCUS T (FT) is an important floral integrator whose functions are conserved across plant species. In soybean, two orthologs, FT2a and FT5a, play a major role in initiating flowering. Their expression in response to different photoperiods is controlled by allelic combinations at the maturity loci E1 to E4, generating variation in flowering time among cultivars. We determined the molecular basis of a quantitative trait locus (QTL) for flowering time in linkage group J (Chromosome 16). Fine-mapping delimited the QTL to a genomic region of 107kb that harbors FT5a We detected 15 DNA polymorphisms between parents with the early-flowering (ef) and late-flowering (lf) alleles in the promoter region, an intron, and the 3' untranslated region of FT5a, although the FT5a coding regions were identical. Transcript abundance of FT5a was higher in near-isogenic lines for ef than in those for lf, suggesting that different transcriptional activities or mRNA stability caused the flowering time difference. Single-nucleotide polymorphism (SNP) calling from re-sequencing data for 439 cultivated and wild soybean accessions indicated that ef is a rare haplotype that is distinct from common haplotypes including lf The ef allele at FT5a may play an adaptive role at latitudes where early flowering is desirable.

HMGB1 exacerbates bronchiolitis obliterans syndrome via RAGE/NF-κB/HPSE signaling to enhance latent TGF-ß release from ECM.

Bronchiolitis obliterans syndrome (BOS), characterized by progressive airflow obstruction, is the main barrier to long-term graft survival after lung transplantation. Despite extensive studies, the mechanisms underlying BOS remain poorly understood, and targeted interventions have not yet been fully developed. In the present study, we employed a mouse model of tracheal transplantation and demonstrated that blockade of HMGB1 alone or combined with heparanase (HPSE) attenuates the development of BOS. It was noted that HMGB1 was first passively released from necrotic/damaged cells as a result of early unavoidable allograft injuries, leading to macrophage infiltration along with HMGB1 active secretion. Mechanistic studies revealed that extracellular HMGB1 acted through its receptor, RAGE, to activate NF-κB, which then bound to the HPSE promoter to transcribe its expression. The enhanced HPSE next released HS-bonded latent TGF-ß from myofibroblast ECM by cleaving HS chains to promote the initiation and progression of BOS. Together, our data suggest that HMGB1 and HPSE could be viable targets for prevention and intervention of fibrotic diseases such BOS after lung transplantation.

Chop Deficiency Protects Mice Against Bleomycin-induced Pulmonary Fibrosis by Attenuating M2 Macrophage Production.

C/EBP homologous protein (Chop) has been shown to have altered expression in patients with idiopathic pulmonary fibrosis (IPF), but its exact role in IPF pathoaetiology has not been fully addressed. Studies conducted in patients with IPF and Chop(-/-) mice have dissected the role of Chop and endoplasmic reticulum (ER) stress in pulmonary fibrosis pathogenesis. The effect of Chop deficiency on macrophage polarization and related signalling pathways were investigated to identify the underlying mechanisms. Patients with IPF and mice with bleomycin (BLM)-induced pulmonary fibrosis were affected by the altered Chop expression and ER stress. In particular, Chop deficiency protected mice against BLM-induced lung injury and fibrosis. Loss of Chop significantly attenuated transforming growth factor ß (TGF-ß) production and reduced M2 macrophage infiltration in the lung following BLM induction. Mechanistic studies showed that Chop deficiency repressed the M2 program in macrophages, which then attenuated TGF-ß secretion. Specifically, loss of Chop promoted the expression of suppressors of cytokine signaling 1 and suppressors of cytokine signaling 3, and through which Chop deficiency repressed signal transducer and activator of transcription 6/peroxisome proliferator-activated receptor gamma signaling, the essential pathway for the M2 program in macrophages. Together, our data support the idea that Chop and ER stress are implicated in IPF pathoaetiology, involving at least the induction and differentiation of M2 macrophages.

A recessive allele for delayed flowering at the soybean maturity locus E9 is a leaky allele of FT2a, a FLOWERING LOCUS T ortholog.

BACKGROUND: Understanding the molecular mechanisms of flowering and maturity is important for improving the adaptability and yield of seed crops in different environments. In soybean, a facultative short-day plant, genetic variation at four maturity genes, E1 to E4, plays an important role in adaptation to environments with different photoperiods. However, the molecular basis of natural variation in time to flowering and maturity is poorly understood. Using a cross between early-maturing soybean cultivars, we performed a genetic and molecular study of flowering genes. The progeny of this cross segregated for two maturity loci, E1 and E9. The latter locus was subjected to detailed molecular analysis to identify the responsible gene. RESULTS: Fine mapping, sequencing, and expression analysis revealed that E9 is FT2a, an ortholog of Arabidopsis FLOWERING LOCUS T. Regardless of daylength conditions, the e9 allele was transcribed at a very low level in comparison with the E9 allele and delayed flowering. Despite identical coding sequences, a number of single nucleotide polymorphisms and insertions/deletions were detected in the promoter, untranslated regions, and introns between the two cultivars. Furthermore, the e9 allele had a Ty1/copia-like retrotransposon, SORE-1, inserted in the first intron. Comparison of the expression levels of different alleles among near-isogenic lines and photoperiod-insensitive cultivars indicated that the SORE-1 insertion attenuated FT2a expression by its allele-specific transcriptional repression. SORE-1 was highly methylated, and did not appear to disrupt FT2a RNA processing. CONCLUSIONS: The soybean maturity gene E9 is FT2a, and its recessive allele delays flowering because of lower transcript abundance that is caused by allele-specific transcriptional repression due to the insertion of SORE-1. The FT2a transcript abundance is thus directly associated with the variation in flowering time in soybean. The e9 allele may maintain vegetative growth in early-flowering genetic backgrounds, and also be useful as a long-juvenile allele, which causes late flowering under short-daylength conditions, in low-latitude regions.

[Risk assessment of Salmonella in broiler chicken].

OBJECTIVE: To assess the risk of foodborne disease caused by Salmonella in broiler chickens from retail to table, and to find effective preventive measures according to the risk assessment results. METHODS: Using dose-response model and Combase database, to evaluate the chicken-Salmonella poisoning risk through the crosscontamination in the kitchen with @ RISK by combining monitoring data of broiler chickens in Heilongjiang Province and related data. RESULTS: According to the results of the quantitative risk assessment, there was a high risk of chicken-Salmonella poisoning because of cross-contamination in the kitchen. Scenario analysis suggested that, if the raw chicken was frozen or refrigerated storage in retail, the average risk of chicken-Salmonella poisoning can be reduced 1/5. CONCLUSION: The risk of Chinese residents suffering from chicken-Salmonella poisoning will be reduced effectively by using cold chain management of raw chicken in retail.

Microbiological Food Safety Surveillance in China.

Microbiological food safety surveillance is a system that collects data regarding food contamination by foodborne pathogens, parasites, viruses, and other harmful microbiological factors. It helps to understand the spectrum of food safety, timely detect food safety hazards, and provide relevant data for food safety supervision, risk assessment, and standards-setting. The study discusses the microbiological surveillance of food safety in China, and introduces the policies and history of the national microbiological surveillance system. In addition, the function and duties of different organizations and institutions are provided in this work, as well as the generation and content of the surveillance plan, quality control, database, and achievement of the microbiological surveillance of food safety in China.

[Probabilistic assessment of dietary exposure to both deoxynivalenol and zearalenone from cereal-based products in Chinese populations].

OBJECTIVE: To elucidate the dietary exposure to deoxynivalenol (DON) and zearalenone (ZEN) from cereal-based products in Chinese populations using the probabilistic assessment approach. METHODS: A total of 292 wheat flours and 347 corn-based products were collected from sampling sites of 107 supermarkets or farmers markets, which were randomly selected from 44 cities of 13 provinces in 2009 by the stratified cluster random sampling method. Then, DON and ZEN contamination levels in these samples above analyzed by UPLC-MS/MS in combination with the food consumption data of 68 959 respondents, who were divided into group 1 aged 3 to 13 years old, and group 2 aged 14 and over 14 years old (≥14 years old), obtained by China National Nutrition and Health Survey in 2002 were investigated. A probabilistic assessment model using Monte Carlo simulation was applied to derive the intake distribution of P(1)-P(99) percentile of dietary exposure to DON and ZEN. Meanwhile, all parameters related to dietary exposure to both toxins were compared with either the provisional maximum tolerable daily intake (PMTDI) of 1 µg·kg(-1)·d(-1) for DON, or the tolerable daily intake (TDI) of 0.25 µg·kg(-1)·d(-1) for ZEN in order to evaluate the risk of dietary intake of two toxins and find the minimum percentile of dietary exposure to these two toxins. The statistical differences of dietary exposure to these two toxins between two groups were achieved by t test. RESULTS: The detection frequencies of DON in wheat flours and corn-based products were 100% (292/292) and 97.4% (338/347), respectively. A total of 21 out of 639 samples (wheat flours: 5/292, corn-based products: 16/347) were positive for DON at the levels exceeding the Chinese regulatory limit of 1 000 µg/kg for DON. And the detection frequencies of ZEN in wheat flours and corn-based products were 53.4% (156/292) and 87.6% (304/347), respectively.54 out of 347 corn-based products and no wheat flours were positive for ZEN at the levels exceeding the Chinese regulatory limit of 60 µg/kg for ZEN. Meanwhile, the mean values (95% CI) of the P(50), P(75), P(90), P(95), P(97.5) and P(99) percentile of dietary exposure to DON in populations of 3 to 13 years old were 0.170 (0.170-0.171), 0.762 (0.759-0.765), 2.066 (2.038-2.069), 3.515 (3.501-3.530), 5.342 (5.314-5.372), and 9.220 (9.155-9.279) µg · kg(-1)·d(-1), which were higher than those in populations of ≥14 years old (0.131 (0.130-0.131), 0.500 (0.498-0.501), 1.280 (1.276-1.285), 2.138 (2.128-2.14), 3.510 (3.494-3.527), and 5.512 (5.474-5.546) µg·kg(-1)·d(-1)), with t values of 87.19, 163.87, 164.66, 157.78, 105.47 and 96.31, and all P values less than 0.001. And the mean values (95% CI) of the P(50), P(75), P(90), P(95), P(97.5) and P(99) percentile of dietary exposure to ZEN in populations of 3 to 13 years old were 0.001 (0.001-0.001), 0.006 (0.006-0.006), 0.039 (0.038-0.039), 0.101 (0.100-0.101), 0.195 (0.194-0.197) and 0.378 (0.374-0.381) µg · kg(-1)·d(-1), which were also higher than those in populations of ≥14 years old (0.001 (0.001-0.001), 0.004 (0.004-0.004), 0.026 (0.026-0.026), 0.061 (0.060-0.061), 0.115 (0.115-0.116) and 0.232 (0.231-0.235) µg·kg(-1)·d(-1)) with T-values of 151.11, 73.80, 96.81, 100.81, 91.93 and 76.13, and all P values less than 0.001. Besides, the minimum percentile of dietary exposure to DON in populations of 3 to 13 years old and ≥14 years old exceeded the corresponding PMTDI of 1 µg·kg(-1)·d(-1) was found in the probability distribution of P(76) (99% percentile = 1.03 µg·kg(-1)·d(-1)) and P(84) (95% percentile = 1.01 µg·kg(-1)·d(-1)) percentile, respectively. And the minimum percentile of dietary exposure to ZEN in populations of 3 to 13 years old and ≥14 years old exceeded the corresponding TDI of 0.25 µg·kg(-1)·d(-1) was found in the probability distribution of P(97) (95% percentile = 0.25 µg·kg(-1)·d(-1)) and P(98) (90% percentile = 0.26 µg·kg(-1)·d(-1)) percentile, respectively. CONCLUSION: The contamination levels of DON and ZEN in wheat flours and corn-based products and the risk of dietary exposure to both DON and ZEN in populations in Chinese populations were at relatively low levels. The dietary exposure to both DON and ZEN in populations of 3 to 13 years old was higher than those in populations of ≥14 years old . Populations of 3 to 13 years old were the populations at the high risk of dietary exposure to both mycotoxins.