Movement and Home Range of Amur Soft-Shell Turtle (Pelodiscus maackii) in the Ussuri River, Heilongjiang Province, China.

Comprehensively understanding the spatial ecology and habitat preferences of endangered species is essential for population restoration and conservation. We investigated the home range and movement of the endangered Amur soft-shell turtle (Pelodiscus maackii) in the Ussuri River, Heilongjiang Province, Northeastern China. The study involved tracking 19 Amur soft-shell turtles from late June to mid-October, 2022, resulting in complete and partial home range size data for eight subadults and two adults, respectively. The primary analysis focused on eight subadults, and the models that best described daily movement were identified. We also explored the potential factors influencing home range size. The mean movement rate ranged from 39.18 ± 20.04 m/day to 72.45 ± 29.36 m/day and was positively correlated with the linear home range and water temperature. The most enlightening estimation of home range was derived from a 95% kernel density estimate, utilizing likelihood cross-validation smoothing while adhering to constraints delineated by the river boundaries. The average size of the home range was determined to be 1.02 hectares and displayed no correlation with body size. Subadults tended to establish well-defined home ranges over time, whereas defining home ranges for adults proved challenging. This research addresses a gap regarding the ecology of the Amur soft-shell turtle and provides a foundation for future conservation plans.

Interactions between the nitrate reductase 2 and catalase 1 fine-tune disease resistance in cassava.

Cassava is one of the most important tuber crops that is used for food, starch and bio-energy. However, cassava is susceptible to a number of diseases, especially cassava bacterial blight (CBB). Nitric oxide (NO) and hydrogen peroxide (H2O2) regulate plant growth and development, as well as stress responses. However, no direct relationships between the enzymes involved in the metabolic enzymes that produce and process these key signaling molecules has been demonstrated. Here, we provide evidence for the interaction between the nitrate reductase 2 (MeNR2) and catalase 1 (MeCAT1) proteins in vitro and in vivo, using yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays, respectively. MeNR2 is a positive regulator and MeCAT1 is a negative regulator of CBB resistance. MeNR2 was localized in the nucleus, cell membrane and peroxisome, while MeCAT1 was localized in the peroxisomes. The interactions between MeNR2 and MeCAT1 also had effects of their respective enzyme activities. Taken together, the data presented here suggested that there is coordination between H2O2 and NO signaling in cassava disease resistance, through the interactions between MeCAT1 and MeNR2.

CPK1-HSP90 phosphorylation and effector XopC2-HSP90 interaction underpin the antagonism during cassava defense-pathogen infection.

Cassava is one of the most important tropical crops, but it is seriously affected by cassava bacteria blight (CBB) caused by the bacterial pathogen Xanthomonas phaseoli pv manihotis (Xam). So far, how pathogen Xam infects and how host cassava defends during pathogen-host interaction remains elusive, restricting the prevention and control of CBB. Here, the illustration of HEAT SHOCK PROTEIN 90 kDa (MeHSP90.9) interacting proteins in both cassava and bacterial pathogen revealed the dual roles of MeHSP90.9 in cassava-Xam interaction. On the one hand, calmodulin-domain protein kinase 1 (MeCPK1) directly interacted with MeHSP90.9 to promote its protein phosphorylation at serine 175 residue. The protein phosphorylation of MeHSP90.9 improved the transcriptional activation of MeHSP90.9 clients (SHI-RELATED SEQUENCE 1 (MeSRS1) and MeWRKY20) to the downstream target genes (avrPphB Susceptible 3 (MePBS3) and N-aceylserotonin O-methyltransferase 2 (MeASMT2)) and immune responses. On the other hand, Xanthomonas outer protein C2 (XopC2) physically associated with MeHSP90.9 to inhibit its interaction with MeCPK1 and the corresponding protein phosphorylation by MeCPK1, so as to repress host immune responses and promote bacterial pathogen infection. In summary, these results provide new insights into genetic improvement of cassava disease resistance and extend our understanding of cassava-bacterial pathogen interaction.

NF-YC15 transcription factor activates ethylene biosynthesis and improves cassava disease resistance.

The nuclear factor Y (NF-Y) transcription factors play important roles in plant development and physiological responses. However, the relationship between NF-Y, plant hormone and plant stress resistance in tropical crops remains unclear. In this study, we identified MeNF-YC15 gene in the NF-Y family that significantly responded to Xanthomonas axonopodis pv. manihotis (Xam) treatment. Using MeNF-YC15-silenced and -overexpressed cassava plants, we elucidated that MeNF-YC15 positively regulated disease resistance to cassava bacterial blight (CBB). Notably, we illustrated MeNF-YC15 downstream genes and revealed the direct genetic relationship between MeNF-YC15 and 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (MeACO1)-ethylene module in disease resistance, as evidenced by the rescued disease susceptibility of MeNF-YC15 silenced cassava plants with ethylene treatment or overexpressing MeACO1. In addition, the physical interaction between 2C-type protein phosphatase 1 (MePP2C1) and MeNF-YC15 inhibited the transcriptional activation of MeACO1 by MeNF-YC15. In summary, MePP2C1-MeNF-YC15 interaction modulates ethylene biosynthesis and cassava disease resistance, providing gene network for cassava genetic improvement.

Embryonic development and transcriptomic analysis in red-eared slider Trachemys scripta elegans under salinity stress.

The elevated salinity in freshwater causes a serious threat to the survival and reproduction of freshwater organisms. The effect of salinity on embryonic development of freshwater turtles is little known. In this study, we investigated the embryonic morphology and underlining mechanism of red-eared slider (Trachemys scripta elegans) in different salinities incubated environment (2.5 ppt and 5 ppt). Results showed that salinity caused various forms of malformed embryos, including brain hypoplasia, eye defects, skeletal dysplasia, deformities of carapace, plastron, limb in the embryo. Severely, salinity could lead to embryos decease. Transcriptome analysis showed that differentially expressed genes induced by salinity primarily enriched in development pathways, metabolism pathways, disease pathways as well as cell processes through KEGG enrichment analysis. In addition, in early and middle embryonic developmental stages, the mRNA expression of apoptotic genes (p38 and bax) significantly increased, whereas anti-apoptotic gene bcl-2 decreased in salinities incubated environment. These findings demonstrated that salinity inhibited the process of embryonic development and damaged organogenesis of turtles through promoting apoptotic pathways.

Seasonal changes in hepatic lipid metabolism and apoptosis in Chinese soft-shelled turtle (Pelodiscus sinensis).

Chinese soft-shelled turtle (Pelodiscus sinensis) hibernates without eating and drinking when the ambient temperature is very low. To better understand the characteristics of energy utilization during hibernation, the turtles in the physiological phases of summer active (SA), Pre-Hibernation (Pre-H), Mid-Hibernation (Mid-H) and early arousal (EA) were sampled. The results showed that the levels of serum triglyceride and hepatic lipid droplet were markedly increased in Pre-H and decreased in Mid-H compared with that in SA, indicating that P. sinensis experiences lipid accumulation in Pre-H and lipid is the predominant energy reserve during hibernation. The mRNA expression levels of genes (FABP and CPT-2) involved in lipolysis and lipid oxidation were up-regulated in Mid-H, while the genes related to lipid synthesis (FAS, ACSL-1, ACC, elovl5, and SCD1) were inhibited in Mid-H. Meanwhile, the mRNA expression levels of endoplasmic reticulum stress marker gene Bip and key genes (ATF4, ATF6, and IRE1α) involving the unfolded protein response were significantly increased in Mid-H and EA. Also, the expression levels of genes (ASK1, JNK1, and Bax) associated with cell apoptosis increased in Mid-H and EA, however, the expression of Bcl2 was inhibited in Mid-H. Therefore, hibernation can cause endoplasmic reticulum stress and apoptosis. The findings will provide a theoretical framework for an animal's cold adaptation and offer insights into preventing and managing metabolic syndrome.

Microplastic Distribution Characteristics and Sources on Beaches That Serve as the Largest Nesting Ground for Green Turtles in China.

The threat of microplastics to marine animals and habitats is increasing, which may affect sea turtle nesting grounds. The Qilianyu Islands are the largest remaining green turtle (Chelonia mydas) nesting grounds in China. Despite being far from the mainland, microplastic pollution cannot be ignored. In this study, the level of microplastic pollution in surface sediments from three different zones, namely, the bottom, intertidal, and supratidal zone, was investigated on North Island, Qilianyu Islands. The results showed that the abundance of microplastics in the supratidal zone was significantly higher than that in the bottom zone and intertidal zone (r = 3.65, p = 0.011), with the highest average abundance of microplastics located on the southwest coast of North Island. In the bottom zone, only plastic blocks (88%) and fibers (12%) were found. The main types of microplastics in the intertidal and supratidal zones were plastic blocks (48%) and foam (42%), with polyethylene (PE) (40%) and polystyrene (PS) (34%) being the predominant components. These types and components of microplastics differed from those in the surrounding seawater, but corresponding types and components were found in the plastic debris on the beach. Meanwhile, it was also observed that there were multiple instances of fragmented plastic on the beach. Thus, we suggest that the microplastics on the beach in North Island were mainly derived from the fragmentation of microplastic debris, indicating secondary microplastics. It is recommended to further strengthen the regular cleaning of plastic debris on the beach, especially the removal of small plastic debris, in order to reduce the pollution from secondary microplastics generated by the fragmentation of beach plastic debris and to better protect China's most important sea turtle nesting site in the South China Sea.

Effects of butyl paraben on behavior and molecular mechanism of Chinese striped-necked turtle (Mauremys sinensis).

Butyl paraben (BuP) is widely used in cosmetics, drugs, and food preservation. Recently it is an identified new pollutant that affects various aspects of reproduction, lipid metabolism, and nervous system. Behavioral activity serves as a pre-warning biomarker for predicting water quality. So, in this study, the changes in some behaviors and its neurotransmitters and cell apoptosis in the brain of Chinese striped-necked turtles (Mauremys sinensis) were studied when the turtles were exposed to BuP concentrations of 0, 5, 50, 500, and 5000 µg/L for 21 weeks. The results showed that, the basking time and altering scores to external stimuli in the groups of 50, 500, and 5000 µg/L were significantly reduced, while the time for body-righting was significantly increased, compared with the control (0 µg/L), indicating that the turtles exhibited depression and inactive behavior. The analysis of neurotransmitter in the brain showed that 5-hydroxytryptamine (5-HT) contents in the groups of 500 and 5000 µg/L were significantly higher than the other groups, which was due to an increase in the mRNA relative expression levels of the 5-HT receptor gene (5-HTR), neurotransmitter transporter genes (Drd4, Slc6a4), and neurotransmitter synthase tryptophan hydroxylase (TPH). Furthermore, GABA transaminase (GABA-T) activity increased in the 500 and 5000 µg/L groups, and tyrosine hydroxylase (TH) activity increased dramatically in the 5000 µg/L group. However, acetyl-CoA (AChE) activity was significantly reduced in these four BuP exposure groups. These changes could be attributed to decreased movement velocity and increased inactivity. Meanwhile, the mRNA expression level of BAX, Bcl-2, caspase-9 and TUNEL assay indicated the occurrence of cell apoptosis in the brains of the higher BuP exposed groups, which may play an important role in neuronal death inducing behavior change. In summary, these findings offer fundamental insights into turtle ecotoxicology and serve as a foundation for a comprehensive assessment of the ecological and health risks associated with BuP.

Altered gut mycobiome in patients with end-stage renal disease and its correlations with serum and fecal metabolomes.

BACKGROUND: The relationship between the gut mycobiome and end-stage renal disease (ESRD) remains largely unexplored. METHODS: In this study, we compared the gut fungal populations of 223 ESRD patients and 69 healthy controls (HCs) based on shotgun metagenomic sequencing data, and analyzed their associations with host serum and fecal metabolites. RESULTS: Our findings revealed that ESRD patients had a higher diversity in the gut mycobiome compared to HCs. Dysbiosis of the gut mycobiome in ESRD patients was characterized by a decrease of Saccharomyces cerevisiae and an increase in various opportunistic pathogens, such as Aspergillus fumigatus, Cladophialophora immunda, Exophiala spinifera, Hortaea werneckii, Trichophyton rubrum, and others. Through multi-omics analysis, we observed a substantial contribution of the gut mycobiome to host serum and fecal metabolomes. The opportunistic pathogens enriched in ESRD patients were frequently and positively correlated with the levels of creatinine, homocysteine, and phenylacetylglycine in the serum. The populations of Saccharomyces, including the HC-enriched Saccharomyces cerevisiae, were frequently and negatively correlated with the levels of various toxic metabolites in the feces. CONCLUSIONS: Our results provided a comprehensive understanding of the associations between the gut mycobiome and the development of ESRD, which had important implications for guiding future therapeutic studies in this field.

Cassava phosphatase PP2C1 modulates thermotolerance via fine-tuning dephosphorylation of antioxidant enzymes.

Global warming is an adverse environmental factor that threatens crop yields and food security. 2C-type protein phosphatases (PP2Cs), as core protein phosphatase components, play important roles in plant hormone signaling to cope with various environmental stresses. However, the function and underlying mechanism of PP2Cs in the heat stress response remain elusive in tropical crops. Here, we report that MePP2C1 negatively regulated thermotolerance in cassava (Manihot esculenta Crantz), accompanied by the modulation of reactive oxygen species (ROS) accumulation and the underlying antioxidant enzyme activities of catalase (CAT) and ascorbate peroxidase (APX). Further investigation found that MePP2C1 directly interacted with and dephosphorylated MeCAT1 and MeAPX2 at serine (S) 112 and S160 residues, respectively. Moreover, in vitro and in vivo assays showed that protein phosphorylation of MeCAT1S112 and MeAPX2S160 was essential for their enzyme activities, and MePP2C1 negatively regulated thermotolerance and redox homeostasis by dephosphorylating MeCAT1S112 and MeAPX2S160. Taken together, this study illustrates the direct relationship between MePP2C1-mediated protein dephosphorylation of MeCAT1 and MeAPX2 and ROS accumulation in thermotolerance to provide insights for adapting to global warming via fine-tuning thermotolerance of the tropical crop cassava.

Comparative toxic effect of ammonia exposure on Mauremys sinensis and invasive species Trachemys scripta elegans.

As one of main pollutants, ammonia could cause adverse effects to aquatic animals. To explore the toxic effects of ammonia on Chinese striped-necked turtles (Mauremys sinensis) and invasive species red-eared slider (Trachemys scripta elegans), we compared the activities of antioxidant enzymes, the mRNA levels of genes involved in immune status, endoplasmic reticulum stress and apoptosis between T. s. elegans and M. sinensis under ammonia exposure for 30 days. The results showed that ammonia obviously increased the activities of SOD, CAT, GPX and T-AOC in both T. s. elegans and M. sinensis, especially CAT and GPX in T. s. elegans were higher than that in M. sinensis. The expression levels of JAK, RELA and Mcl-1 in T. s. elegans obviously increased, while IL-6 mRNA levels significantly increased in M. sinensis. In addition, Bip and IRE1 levels in M. sinensis showed a marked increase, and were significantly higher than that in T. s. elegans. Bcl-2 and Bcl-xL transcriptional levels in T. s. elegans showed an increase, especially Bcl-xL were significantly higher than that in M. sinensis. These results indicated that T. s. elegans exhibited more stronger antioxidant defense and immune function than M. sinensis under ammonia exposure. M. sinensis was more likely to occur endoplasmic reticulum stress and inflammation in ammonia environment. This research reveals the physiological response of turtles to ammonia, helps to understand adverse effects of environmental pressure on aquatic turtles, and further explains the tolerance of invasive species T. s. elegans to environmental pollution.

Prevalence of and associated factors for sarcopenia in patients with liver cirrhosis: A systematic review and meta-analysis.

BACKGROUND: Sarcopenia is associated with poor outcomes in patients with cirrhosis. However, the prevalence of and associated factors for developing sarcopenia in this population remain to be determined. OBJECTIVES: This study aimed to summarize the prevalence, characteristics, and associated factors of sarcopenia in patients with cirrhosis. METHODS: Electronic searches were performed from inception to June 9, 2022 to identify the eligible studies. We meta-analyzed the prevalence of sarcopenia in overall patients with cirrhosis and subgroups. Both crude and adjusted odds ratios (ORs) were pooled using the random effects model. RESULTS: A total of 55 studies involving 13,158 patients from 17 countries were included. The overall prevalence of sarcopenia was 40.1 % (95 % CI 35.4%-44.9 %) in patients with cirrhosis. The pooled prevalence was higher in males, Child-Pugh class C cirrhosis, decompensated stage, ascites, subjective global assessment class C cirrhosis, and when sarcopenia was defined by L3-SMI (third lumbar-skeletal muscle index) at a higher cutoff. In multivariate analysis, older age (adjusted OR 1.04, 95 % CI 1.00-1.07), male (adjusted OR 4.75, 95 % CI 2.72-8.28), lower body mass index (BMI) (adjusted OR 0.78, 95 % CI 0.73-0.83), alcoholic liver disease (ALD) (adjusted OR 1.43, 95 % CI 1.19-1.72), but not ascites and hepatic encephalopathy, were significantly associated with an increased risk of sarcopenia in patients with cirrhosis. CONCLUSION: Sarcopenia is a prevalent complication, and older age, male patients, lower BMI, and patients with ALD are associated with an increased risk of sarcopenia in patients with cirrhosis.

Coat protein of cassava common mosaic virus targets RAV1 and RAV2 transcription factors to subvert immunity in cassava.

Cassava common mosaic virus (CsCMV, genus Potexvirus) is a prevalent virus associated with cassava mosaic disease, so it is essential to elucidate the underlying molecular mechanisms of the coevolutionary arms race between viral pathogenesis and the cassava (Manihot esculenta Crantz) defense response. However, the molecular mechanism underlying CsCMV infection is largely unclear. Here, we revealed that coat protein (CP) acts as a major pathogenicity determinant of CsCMV via a mutant infectious clone. Moreover, we identified the target proteins of CP-related to abscisic acid insensitive3 (ABI3)/viviparous1 (VP1) (MeRAV1) and MeRAV2 transcription factors, which positively regulated disease resistance against CsCMV via transcriptional activation of melatonin biosynthetic genes (tryptophan decarboxylase 2 (MeTDC2), tryptamine 5-hydroxylase (MeT5H), N-aceylserotonin O-methyltransferase 1 (MeASMT1)) and MeCatalase6 (MeCAT6) and MeCAT7. Notably, the interaction between CP, MeRAV1, and MeRAV2 interfered with the protein phosphorylation of MeRAV1 and MeRAV2 individually at Ser45 and Ser44 by the protein kinase, thereby weakening the transcriptional activation activity of MeRAV1 and MeRAV2 on melatonin biosynthetic genes, MeCAT6 and MeCAT7 dependent on the protein phosphorylation of MeRAV1 and MeRAV2. Taken together, the identification of the CP-MeRAV1 and CP-MeRAV2 interaction module not only illustrates a molecular mechanism by which CsCMV orchestrates the host defense system to benefit its infection and development but also provides a gene network with potential value for the genetic improvement of cassava disease resistance.

Angiotensin-(1-7) plays an important role in regulating spermatogenesis in Trachemys scripta elegans under salinity stress.

Elevation in water salinity can threaten the spermatogenesis and fertility of freshwater animals. The role of the renin-angiotensin system (RAS) in regulating spermatogenesis has attracted considerable attention. Our previous study found that red-eared sliders (Trachemys scripta elegans), could survive in 10 PSU water for over 1 year. To understand the chronic impact of salinity on testicular spermatogenesis and underlying mechanisms, male T. s. elegans were subjected to treatment with water of 5 PSU and 10 PSU for a year, and spermatogenesis and regulation of the RAS signal pathway was assessed. Results showed induced inflammation in the testes of T. s. elegans in the 10 PSU group, as evidenced by a decrease in the number of testicular germ cells from 1586 to 943. Compared with the control group, the levels of proinflammatory genes, including TNF-α, IL-12A and IL-6 were elevated 3.1, 0.3, and 1.4 times, respectively, in animals exposed to 10 PSU water. Testicular antiapoptotic processes of T. s. elegans might involve the vasoactive peptide angiotensin-(1-7) in the RAS, as its level was significantly increased from 220.2 ng ml-1 in controls to 419.2 ng ml-1 in the 10 PSU group. As expected, specific inhibitor (A-779) for the Ang-(1-7) acceptor effectively prevented the salinity-induced upregulation of genes encoding anti-inflammatory and antiapoptotic factors (TGF-ß1, Bcl-6) in the testis of the 10 PSU animals, whereas it promoted the upregulation of proinflammatory and proapoptotic factors (TNF-α, IL-12A, IL-6, Bax and caspase-3). Our data indicated that Ang-(1-7) attenuates the effect of salinity on inflammation and apoptosis of the testis in T. s. elegans. A new perspective to prevent salinity-induced testis dysfunction is provided.

Morphological and transcriptomic analyses of embryonic development of red-eared slider Trachemys scripta elegans.

Embryology provides an understanding of individual's origin and developmental patterns. Turtles are among the oldest living reptiles and have unique body structure. However, the morphogenesis and mechanisms of turtles are not fully understood. In this study, we focused on the embryonic development of red-eared slider (Trachemys scripta elegans) which widely distributes in the world. At an incubation temperature of 28 °C, the turtle eggs had a 61-day incubation cycle, and the entire embryonic development process was divided into 27 stages and 3 phases according to variations in age, body size, and morphological characteristics. The early phase of embryonic development (the first 12 stages) were characterized by embryo growth, and the appearance of internal organ precursors. The middle phase (stages 13-20) involved prominent heart division at stage 13 and the appearance of carapace and plastron at stages 14 and 17, respectively. In the later phase (stages 21-27), the hatchlings formed, and the carapace and plastron thickened. Transcriptome analysis of embryos showed enrichment of the differential genes in pathways related to development, metabolism, disease, and cellular processes. The Kyoto Encyclopedia of Genes and Genomes enrichment (KEGG) analysis implied the crucial regulatory role of the axon guidance pathway. Real-time fluorescence quantitative PCR indicated upregulated expression of wnt5a and bmp7 in stages 7 and 16 compared to that in stage 12. This study revealed the development process of red-eared slider embryo and the dynamics of the signaling pathway affecting its development, which supplemented the theory of embryo development, and provided new ideas for the molecular mechanism of turtle embryo development.

Toxicological effects of copper on bioaccumulation and mRNA expression of antioxidant, immune, and apoptosis-related genes in Chinese striped-necked turtle (Mauremys sinensis).

Heavy metals are among the most ubiquitous environmental pollutants of recent decades. Copper is commonly used to control algal blooms or macrophyte and waste infestations, its ambient concentration has increased significantly, indicating possible environmental risk. To investigate the effects of copper exposure on bioaccumulation, antioxidant defense, immune response, and apoptosis in the Chinese Striped-necked Turtle Mauremys sinensis, three experimental groups, control (0.0 mg/L), Cu2 (2 mg/L) and Cu4 (4 mg/L) were designed, and sampled at 14 and 28 days. Results showed that copper accumulates in different organs depending on the concentration and exposure time, Liver > Kidney > Gut > Heart > Brain > Muscle and the time order was 28 days > 14 days. The liver enzymes AST, ALT, and ALP decreased when the turtles were exposed to copper stress, while the contents of bilirubin TBIL, DBIL, IBIL, and LDH showed a significant upward trend. Similarly, the mRNA expression level of acetylcholinesterase AChE in the brain was significantly downregulated upon copper exposure. An upward trend was noticed in the liver Metallothionein MT mRNA expression levels compared to the control group. The mRNA expression levels of antioxidant enzymes CAT, SOD, MnSOD, and GSH-PX1 in the liver increased initially and then significantly decreased. Furthermore, the relative mRNA expression levels of inflammatory cytokines IL-1ß, IL-8, TNF-α, and IFN-γ involved in inflammatory response significantly upregulated. Copper significantly increased the hepatic mRNA transcription of heat shock proteins HSP70 and HSP90 at different exposure durations. In addition, the relative mRNA levels of caspase3, caspase8, and caspase9 related to the caspase-dependent apoptotic pathway significantly increased under copper stress. These results explain that copper toxicity causes bioaccumulation, promotes oxidative stress, obstructs immunity, and induces inflammation and apoptosis by altering their gene expression levels in M. sinensis.

Naringenin Improves Innate Immune Suppression after PRRSV Infection by Reactivating the RIG-I-MAVS Signaling Pathway, Promoting the Production of IFN-I.

Porcine reproductive and respiratory syndrome (PRRS) has been prevalent for nearly forty years since it was first reported. It has been one of the major diseases jeopardizing the healthy development of the world swine industry, as well as causing great economic losses to the industry's economic development. Furthermore, no way has been found to combat the disease due to the immunosuppressive properties of its pathogen porcine reproductive and respiratory syndrome virus (PRRSV) infection. We previously examined the mRNA expression of IFN-I in PRRSV-infected Marc-145 cells at different time periods using qRT-PCR, and found that the mRNA expression of IFN-I in the late stage of PRRSV infection showed suppression. Naringenin is a flavonoid found in citrus fruits and has a very wide range of pharmacological activities. Therefore, the aim of the present study was to investigate the modulatory effect of naringenin on the suppressed innate immune response after PRRSV infection. The expression of IFN-I, IL-10, and ISGs in the late stage of PRRSV infection was examined using qRT-PCR, and the results showed that naringenin improved the expression of antiviral cytokines suppressed by PRRSV infection. Further results showed that naringenin treatment significantly up-regulated the expression of proteins related to the RIG-I-MAV immune signaling pathway, and that naringenin could not significantly activate the RIG-I-MAVS signaling pathway after the addition of the RIG-I inhibitor Cyclo. Overall, these data demonstrated that naringenin could improve the innate immune response suppressed by PRRSV infection by modulating the RIG-I-MAVS signaling pathway. Therefore, our study will provide a theoretical basis for the development of naringenin as a drug against immunosuppressive viral infectious disease infections.