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1.
Aquat Toxicol ; 220: 105406, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31945653

RESUMO

Currently, feed adulteration and contamination with melamine (MEL) are considered one of the serious issues in the aquatic industry. With the limited studies of MEL exposure alone in fish, its adverse impacts on fish cannot be evaluated well. Accordingly, this study aimed to investigate the effects of MEL containing diets on the immune response, disease resistance to Aeromonas hydrophila, growth performance, chemical composition, immune-related genes expression, and histopathology of both spleen and head kidneys. Also, the efficacy of curcumin (CUR) dietary supplementation to alleviate MEL negative impacts were evaluated. A total of 180 apparently healthy Oreochromis niloticus (O. niloticus) were divided into four groups with three replicates fed the basal diet only, basal diet fortified with 200 mg/kg CUR, basal diet containing 1 % MEL, or a basal diet containing CUR + MEL. The results displayed that MEL significantly reduced growth performance indices and body crude lipid contents. Anemic, leukopenic, lymphocytopenic, heterocytopenic, esonipenic, hypoproteinemic and hypoalbuminic conditions were apparent. Moreover, depleted immune and antioxidant indicators including lysozyme activity, nitric oxide, immunoglobulin M, complement 3, glutathione peroxidase, and superoxide dismutase enzyme activity were recorded. Also, MEL reduced the disease resistance of O. niloticus to bacterial infection. Furthermore, MEL induced downregulation of mRNA levels of interleukin 1ß and tumor necrosis factor α in the spleen together with obvious pathological perturbations in both spleen and head kidneys. The CUR addition resulted in a significant enhancement in most indices. These results may conclude that MEL could alter both innate and adaptive immune responses via the negative transcriptional effect on immune-related genes together with the oxidative damage of the immune organs. Furthermore, CUR dietary supplements could be advantageous for mitigating MEL negative impacts, thus offering a favorable aquafeed additive for O. niloticus.


Assuntos
Ração Animal/análise , Ciclídeos , Curcumina/farmacologia , Citocinas/biossíntese , Resistência à Doença/efeitos dos fármacos , Contaminação de Alimentos/análise , Triazinas/toxicidade , Aeromonas hydrophila/crescimento & desenvolvimento , Animais , Antioxidantes/metabolismo , Ciclídeos/sangue , Ciclídeos/crescimento & desenvolvimento , Ciclídeos/metabolismo , Suplementos Nutricionais , Resistência à Doença/imunologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/prevenção & controle , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/prevenção & controle , Rim Cefálico/efeitos dos fármacos , Rim Cefálico/metabolismo , Estresse Oxidativo/efeitos dos fármacos
2.
Plant Physiol Biochem ; 147: 322-335, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31911359

RESUMO

It is well known that parasitic weeds such as Orobanche (broomrape) significantly decrease crop growth and yield. Although hormonal priming is a well-known inducer of plant resistance against broomrapes (Orobanche spp.), the metabolic events associated with such resistance are poorly understood. Therefore, the current work was undertaken to elucidate the role of SA in inducing tomato resistance against Orobanche, considering its impact on carbon and nitrogen metabolism of the host. Total carbon and nitrogen and levels of carbon (sugars, organic acids and fatty acids) and nitrogen (amino acids and polyamines)-containing metabolites as well as the activities of some key enzymes involved in their metabolic pathways were evaluated. Broomrape infection significantly disrupted C/N ratio in the host roots. On contrary, SA treatment markedly induced accumulation of sugars, organic acids, fatty acids, amino acids as well as polyamines in healthy plants. Under broomrape challenge, SA mitigated the infection-induced growth inhibition by improving the level of nitrogen-containing osmoprotectants (proline, arginine and some polyamines). However, a decrease was observed in some C and N assimilates which are well known to be potentially transferred to the parasite, such as sucrose, asparagine, alanine, serine and glutamate. Interestingly, SA treatment induced the catapolism of polyamines and fatty acids in the host root. Accordingly, our study suggests that SA-induced resistance against broomrape relies on the rational utilization of C and N assimilates in a manner that disturbs the sink strength of the parasite and/or activates the defense pool of the host.


Assuntos
Carbono , Resistência à Doença , Lycopersicon esculentum , Nitrogênio , Orobanche , Ácido Salicílico , Carbono/metabolismo , Resistência à Doença/efeitos dos fármacos , Lycopersicon esculentum/efeitos dos fármacos , Lycopersicon esculentum/parasitologia , Nitrogênio/metabolismo , Orobanche/fisiologia , Ácido Salicílico/farmacologia
3.
Food Chem ; 305: 125483, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610420

RESUMO

Kiwifruit (Actinidia deliciosa cv. Jinkui) were treated with 0.1 mmol/L methyl jasmonate (MeJA) to investigate the effects on disease resistance to soft rot caused by Botryosphaeria dothidea. The results showed that MeJA treatment significantly reduced the diameter of lesions after inoculation with B. dothidea. This treatment significantly enhanced the activities of related antioxidant protective enzymes, defence-related enzymes including catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), polyphenol oxidase (PPO), chitinase (CHI), ß-1,3 glucanase (GLU) and increased the accumulation of total phenolic content, while the degree of membrane lipid peroxidation was reduced. MeJA treatment effectively enhanced gene expression of AcPOD, AcSOD, AcCHI and AcGLU. The results from this research suggest that MeJA treatment is a promising and safe strategy for controlling postharvest rot soft of kiwifruit.


Assuntos
Acetatos/farmacologia , Actinidia/microbiologia , Ascomicetos/efeitos dos fármacos , Ciclopentanos/farmacologia , Resistência à Doença/efeitos dos fármacos , Oxilipinas/farmacologia , Actinidia/química , Actinidia/metabolismo , Ascomicetos/fisiologia , Quitinases/genética , Quitinases/metabolismo , Frutas/química , Frutas/metabolismo , Frutas/microbiologia , Expressão Gênica/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidase/genética , Peroxidase/metabolismo , Fenóis/análise , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
4.
Plant Biol (Stuttg) ; 22(1): 70-80, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31283085

RESUMO

The effects of elevated glutathione levels on defence responses to powdery mildew (Euoidium longipes) were investigated in a salicylic acid-deficient tobacco (Nicotiana tabacum cv. Xanthi NahG) and wild-type cv. Xanthi plants, where salicylic acid (SA) contents are normal. Aqueous solutions of reduced glutathione (GSH) and its synthetic precursor R-2-oxothiazolidine-4-carboxylic acid (OTC) were injected into leaves of tobacco plants 3 h before powdery mildew inoculation. SA-deficient NahG tobacco was hyper-susceptible to E. longipes, as judged by significantly more severe powdery mildew symptoms and enhanced pathogen accumulation. Strikingly, elevation of GSH levels in SA-deficient NahG tobacco restored susceptibility to E. longipes to the extent seen in wild-type plants (i.e. enhanced basal resistance). However, expression of the SA-mediated pathogenesis-related gene (NtPR-1a) did not increase significantly in GSH or OTC-pretreated and powdery mildew-inoculated NahG tobacco, suggesting that the induction of this PR gene may not be directly involved in the defence responses induced by GSH. Our results demonstrate that artificial elevation of glutathione content can significantly reduce susceptibility to powdery mildew in SA-deficient tobacco.


Assuntos
Ascomicetos , Resistência à Doença , Glutationa , Ácido Salicílico , Tabaco , Ascomicetos/efeitos dos fármacos , Ascomicetos/fisiologia , Resistência à Doença/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas , Glutationa/metabolismo , Glutationa/farmacologia , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/microbiologia , Tabaco/química , Tabaco/microbiologia
5.
PLoS One ; 14(12): e0226951, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31877189

RESUMO

Crop plants always encounter multiple stresses in the natural environment. Here, the effects of the fungicide zinc thiazole (ZT) on propagation of Ralstonia solanacearum, a bacterial pathogen, were investigated in peanut seedlings under salt stress. Compared with water control, salt stress markedly reduced pathogen resistance in peanut seedlings. However, impaired pathogen resistance was alleviated by treatment with dimethylthiourea, a specific ROS scavenger, or ZT. Subsequently, salt stress or combined salt and pathogen treatment resulted in inhibition of photosynthesis, loss of chlorophyll and accumulation of thiobarbituric acid reactive substances, which could be reversed by ZT. In addition, ZT treatment suppressed the salt stress up-regulated Na+ content and Na+/K+ ratios in peanut roots. Furthermore, salt stress or combined salt and pathogen treatment impaired the activities of antioxidant (e.g. superoxide dismutase/SOD and catalase/CAT), and defense-related (e.g. phenylalanine ammonia lyase /PAL and polyphenol oxidase/PPO) enzymes, which could be rescued by addition of ZT. In contrast, only slight changes of SOD and CAT activities were observed in pathogen-infected seedlings. Similarly, activities of PAL and PPO were slightly modified by salt stress in peanut seedlings. These results suggest that the ZT-enhanced pathogen resistance can be partly attributed to the improvement of photosynthetic capacity and defense enzyme activities, and also the inhibition of Na+/K+ ratios, in this salt-stressed crop plant.


Assuntos
Arachis/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Doenças das Plantas/prevenção & controle , Ralstonia solanacearum/efeitos dos fármacos , Arachis/enzimologia , Arachis/microbiologia , Arachis/fisiologia , Resistência à Doença/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Doenças das Plantas/microbiologia , Ralstonia solanacearum/fisiologia , Estresse Salino , Tolerância ao Sal/efeitos dos fármacos , Tiazóis/farmacologia , Zinco/farmacologia
6.
Fish Shellfish Immunol ; 94: 880-888, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31562894

RESUMO

The humpback grouper (Cromileptes altivelis) is a commercially valuable species of the family Epinephelidae; however, its marketization suffers from slow growth speed, low survival rate, and various pathogenic diseases. Lactococcus lactis and Schizochytrium limacinum are commonly used as immunostimulants due to their health benefits for the aquatic organisms. In the present study, we assessed the effects of dietary supplementation with L. lactis HNL12 combined with S. limacinum algal meal on the growth performances, innate immune response, and disease resistance of C. altivelis against Vibrio harveyi. The results showed that fish fed with a combination diet of L. lactis and S. limacinum exhibited significantly higher final weight, percent weight gain, and specific growth rate compared with groups fed with them alone. A bacterial challenge experiment indicated that the group fed with the L. lactis combined with S. limacinum diet achieved the highest relative percent of survival value (68.63%), suggesting that L. lactis and S. limacinum significantly improved the disease resistance against V. harveyi after a 4-week feeding trial. Moreover, the respiratory burst activity of macrophages of fish fed with a L. lactis combined with S. limacinum diet was significantly higher than that of fish fed the control diet after 1, 2, and 3 weeks of feeding. The serum superoxide dismutase of fish fed with a L. lactis combined with S. limacinum diet significantly increased compared to those fed the control diet after 1 and 2 weeks of feeding, while the serum alkaline phosphatase of fish fed with a L. lactis combined with S. limacinum diet after 2 and 4 weeks was significantly increased, compared to the control group. The serum lysozyme activities of fish fed with a L. lactis combined with S. limacinum diet significantly increased compared to the control group after 2 weeks of feeding. Furthermore, transcriptome sequencing of the C. altivelis head kidney was conducted to explore the immune-regulating effects of the L. lactis combined with S. limacinum diet on C. altivelis. A total of 86,919 unigenes, annotated by at least one of the reference databases (Nr, Swiss-Prot, GO, COG, and KEGG), were assembly yielded by de novo transcriptome. In addition, 157 putative differentially expressed genes (DEGs) were identified between the L. lactis combined with S. limacinum group and the control group. For pathway enrichment, the DEGs were categorized into nine KEGG pathways, which were mainly related to infective diseases, antigen processing and presentation, digestive system, and other immune system responses. The findings of this study suggest that the L. lactis combined with S. limacinum diet can induce positive effects on the growth, immunity, and disease resistance of C. altivelis against V. harveyi. This study expands our understanding of the synergistic combinations of probiotics and prebiotics in aquaculture.


Assuntos
Bass/imunologia , Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Lactococcus lactis/química , Prebióticos , Probióticos/farmacologia , Estramenópilas/química , Adjuvantes Imunológicos/farmacologia , Animais , Bass/crescimento & desenvolvimento , Resistência à Doença/efeitos dos fármacos , Resistência à Doença/imunologia , Vibrio/fisiologia , Vibrioses/imunologia , Vibrioses/veterinária
7.
Carbohydr Polym ; 225: 115221, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521273

RESUMO

Alginate Oligosaccharide (AOS) is a natural biological carbohydrate extracted from seaweed. In our study, Arabidopsis thaliana was used to evaluate the AOS-induced resistance to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Resistance was vitally enhanced at 25 mg/L in wild type (WT), showing the decreased disease index and bacteria colonies, burst of ROS and NO, high transcription expression of resistance genes PR1 and increased content of salicylic acid (SA). In SA deficient mutant (sid2), AOS-induced disease resistance dropped obviously compared to WT. The disease index was significantly higher than WT and the expression of recA and avrPtoB are two and four times lower than WT, implying that AOS induces disease resistance injecting Pst DC3000 after three days treatment by arousing the SA pathway. Our results provide a reference for the profound research and application of AOS in agriculture.


Assuntos
Arabidopsis/metabolismo , Resistência à Doença/efeitos dos fármacos , Oligossacarídeos/metabolismo , Doenças das Plantas/microbiologia , Pseudomonas syringae/efeitos dos fármacos , Proteínas de Arabidopsis , Feófitas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico/metabolismo
8.
Carbohydr Polym ; 225: 115227, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521296

RESUMO

This study investigated the effects of dietary chitosan on the growth performance and nonspecific immunity of loaches (Misgurnus anguillicadatus). Four practical diets at three levels of chitosan (1, 5 and 10 g/kg) were fed to loach (3.13 ±â€¯0.02 g) in triplicate groups (20 fish per replicate) for 10 weeks. Contrary to high-chitosan treatment, the administration of low or moderate levels of oral chitosan (1 or 5 g/kg) significantly increased the body weight gain, specific growth rate and condition factor. The oral administration of chitosan significantly increased the survival rate, phenoloxidase, superoxide dismutase, glutathione peroxidase, lysozyme, acid phosphatase and alkaline phosphatase activities, as well as the immunoglobulin M and complement 3 contents and the disease resistance against Aeromonas hydrophila. The optimum dose of dietary chitosan required for the maximum growth of loach was 5 g/kg. These results indicated that chitosan exerted immunostimulatory effects on loaches (M. anguillicadatus) and can thus be used as a dietary supplement.


Assuntos
Quitosana/farmacologia , Cipriniformes , Resistência à Doença/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas , Imunidade Inata/efeitos dos fármacos , Aeromonas hydrophila/efeitos dos fármacos , Ração Animal , Animais , Cipriniformes/crescimento & desenvolvimento , Cipriniformes/imunologia , Cipriniformes/metabolismo , Suplementos Nutricionais , Doenças dos Peixes/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/veterinária , Alimentos Marinhos
9.
Fish Shellfish Immunol ; 94: 548-557, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31539573

RESUMO

A 56-day growth trial was conducted to investigate the effects of dietary yeast hydrolysate on the growth performance, antioxidation, immune response and resistance against Aeromonas hydrophila in largemouth bass. Four experimental diets were prepared with yeast hydrolysate levels of 0% (Y0), 1.5% (Y1.5), 3.0% (Y3.0) and 4.5% (Y4.5). Each diet was randomly assigned to triplicate 150-L tanks and each tank was stocked with 30 largemouth bass (initial body weight, IBW = 7.71 ±â€¯0.02 g). A challenge test was carried out after the feeding trial by injecting A. hydrophila intraperitoneally for 4-day observation. The results showed that the FBW and WGR in Y1.5 group were significantly higher than those in Y0 group (P < 0.05) and the feed conversion ratio (FCR) got the lowest value in Y1.5 group. And the hydrolysate supplement significantly increased the 4-day cumulative survival rate after the bacterial challenge (P < 0.05). The plasma malondialdehyde was lower in the yeast hydrolysate supplement groups in both pre- and post-challenge test (P < 0.05), while the plasma C3 increased (P < 0.05). In post-challenge test, the plasma superoxide dismutase (SOD) and catalase (CAT) activities increased in the Y1.5 and Y3.0 groups respectively (P < 0.05), and plasma lysozyme in Y1.5 group and the plasma IgM in Y3.0 group were higher than those in others respectively (P < 0.05). For the q-PCR results, in post-challenge test, the hepatic hep2 expression level in Y1.5 and Y4.5 groups were both significantly higher than those in others (P < 0.05), as well as il-8 in Y3.0 group. The spleen hif-1alpha and tgf-beta1 expression levels in Y4.5 group were all significantly lower than those in others (P < 0.05), while the gilt was significantly higher (P < 0.05) in the post-challenge test. And the expression levels of spleen tnf-alpah1 in Y1.5 and Y3.0 groups and il-8 in Y3.0 group were all significantly higher than those in other groups (P < 0.05) in the post-challenge test. The head kidney gilt expression level was significantly higher in the yeast hydrolysate supplement groups compared with the Y0 group (P < 0.05), and the head kidney il-8 expression level in Y1.5 group was significant higher than those in other groups in post-challenge test (P < 0.05). The present results indicated dietary yeast hydrolysate improved the antioxidant ability and enhanced the immune response of largemouth bass without negative effect on growth. And 1.5% or 3.0% of dietary yeast hydrolysate was recommended for largemouth bass based on the present results.


Assuntos
Bass , Resistência à Doença/efeitos dos fármacos , Doenças dos Peixes/imunologia , Expressão Gênica/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Fermento Seco/metabolismo , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Bass/crescimento & desenvolvimento , Dieta/veterinária , Suplementos Nutricionais/análise , Doenças dos Peixes/genética , Doenças dos Peixes/metabolismo , Infecções por Bactérias Gram-Negativas/genética , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/metabolismo , Fermento Seco/administração & dosagem
10.
Fish Shellfish Immunol ; 94: 558-565, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31546036

RESUMO

In this study, we demonstrate the enhanced disease resistance and positive immunomodulation of novel pectin isolated from Spirulina maxima (SmP) in zebrafish model. Zebrafish larvae exposed to SmP had significantly (p < 0.05) higher cumulative percent survival (CPS) at 25 (44.0%) and 50 µg/mL (67.0%) against Edwardsiella piscicida compared to the control. However, upon Aeromonas hydrophila challenge, SmP exposed larvae at 50 µg/mL had slightly higher CPS (33.3%) compared to control group (26.7%). SmP supplemented zebrafish exhibited the higher CPS against E. piscicida (93.3%) and A. hydrophila (60.0%) during the early stage of post-infection (<18 hpi). qRT-PCR results demonstrated that exposing (larvae) and feeding (adults) of SmP, drive the modulation of a wide array of immune response genes. In SmP exposed larvae, up-regulation of the antimicrobial enzyme (lyz: 3.5-fold), mucin (muc5.1: 2.84, muc5.2: 2.11 and muc5.3: 2.40-fold), pro-inflammatory cytokines (il1ß: 1.79-fold) and anti-oxidants (cat: 2.87 and sod1: 1.82-fold) were identified. In SmP fed adult zebrafish (gut) showed >2-fold induced pro-inflammatory cytokine (il1ß) and chemokines (cxcl18b, ccl34a.4 and ccl34b.4). Overall results confirmed the positive modulation of innate immune responses in larval stage and it could be the main reason for developing disease resistance against E. piscicida and A. hydrophila. Thus, non-toxic, natural and biodegradable SmP could be considered as the potential immunomodulatory agent for sustainable aquaculture.


Assuntos
Cianobactérias/química , Resistência à Doença/efeitos dos fármacos , Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Pectinas/metabolismo , Peixe-Zebra/metabolismo , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/metabolismo , Dieta/veterinária , Proteínas na Dieta/administração & dosagem , Proteínas na Dieta/metabolismo , Suplementos Nutricionais/análise , Edwardsiella/fisiologia , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/veterinária , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Pectinas/administração & dosagem
11.
Plant Mol Biol ; 101(3): 315-323, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392474

RESUMO

KEY MESSAGE: Pre-treatment of soybean seedlings with 200 µM salicylic acid before fungal inoculation significantly alleviated disease resistance in soybean seedlings against Fusarium solani infection. Sudden death syndrome of soybean is largely caused by Fusarium solani (F. solani). Salicylic acid (SA) has been reported to induce resistance in plants against many pathogens. However, the effect of exogenous SA application on F. solani infection of soybean is less reported. This study investigated the effect of foliar application of SA on soybean seedlings before F. solani infection. Seedlings were sprayed with 200 µM SA and inoculated with F. solani after 24 h of last SA application. After 3 days post-inoculation, seedlings treated with 200 µM SA showed significantly fewer disease symptoms with increased endogenous SA level, SA marker genes expression and antioxidant activities in the SA-treated seedlings more than the untreated control seedlings. Furthermore, the decrease in hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels was observed in the SA-treated plants as compared to the untreated plants. Analysis of the effect of SA application on F. solani showed that the mycelia growth of F. solani was not affected by SA treatment. Further investigation in this study revealed a decreased in F. solani biomass content in the SA treated seedlings. Results from the present study show that pre-treatment of 200 µM SA can induce resistance of soybean seedlings against F. solani infection.


Assuntos
Resistência à Doença/efeitos dos fármacos , Fusarium/patogenicidade , Doenças das Plantas/microbiologia , Ácido Salicílico/farmacologia , Soja/microbiologia , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/microbiologia , Plântula/efeitos dos fármacos , Plântula/microbiologia , Soja/efeitos dos fármacos
12.
Fish Shellfish Immunol ; 93: 711-719, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31419532

RESUMO

In the present study, we aimed to screen the potential probiotic Bacillus subtilis isolated from the gut of healthy fish using in vitro assays and to evaluate its effect on Dabry's sturgeon (Acipenser dabryanus) using in vivo feeding experiments. Among the isolates, B. subtilis BSth-5 and BSth-19 exhibited antimicrobial effect against four sturgeon-pathogenic bacteria, including Aeromonas hydrophila, A. veronii, A. media, and Streptococcus iniae. The cell number of B. subtilis BSth-5 and BSth-19 changed little after 2 h of exposure to pH 3.0 or fresh Dabry's sturgeon bile at 2.5% and 5.0%. Meanwhile, B. subtilis BSth-5 and BSth-19 produced extracellular protease, cellulose, and lipase. And it was proved that B. subtilis BSth-5 and BSth-19 were harmless after injection of Dabry's sturgeon. One group of Dabry's sturgeon was fed a control diet and two groups were fed experimental diets containing 2.0 × 108 CFU/g BSth-5 (T1 group) or BSth-19 (T2 group) for 8 weeks. No significant differences in final weight, weight gain rate, and special growth rate were observed in the T1 and T2 groups compared to the control group (P > 0.05), but a significant improvement in survival rate was detected after 4 and 8 weeks of feeding (P < 0.05). After 8 weeks, serum total antioxidant capacity, total superoxide dismutase activity, and IgM levels were significantly higher in the T1 and T2 groups compared to the control group (P < 0.05). Moreover, serum lysozyme activity was significantly higher in the T1 group relative to the control group during the whole experiment period (P < 0.05); however, the differences were not significant between the T2 and control groups (P > 0.05). Serum malondialdehyde levels in the T1 and T2 groups were significantly lower than those in the control group after 4 weeks (P < 0.05). Sturgeons in the T1 and T2 groups showed a higher survival rate after Aeromonas hydrophila infection. To summarize, dietary supplementation with BSth-5 and BSth-19 could enhance the survival rate, antioxidant activity, serum immunity, and disease resistance in A. dabryanus.


Assuntos
Bacillus subtilis/química , Resistência à Doença/imunologia , Doenças dos Peixes/imunologia , Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Probióticos/farmacologia , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Dieta/veterinária , Resistência à Doença/efeitos dos fármacos , Peixes/sangue , Peixes/crescimento & desenvolvimento , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária
13.
Fish Shellfish Immunol ; 93: 500-507, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377430

RESUMO

A feeding trial was conducted to evaluate the effects of different molar mass chitooligosaccharides (1000 Da, 3000 Da and 8000 Da) on growth, antioxidant capacity, non-specific immune response, and resistance to Aeromonas hydrophila in GIFT tilapia (Oreochromis niloticus). A total of 600 fish were divided into four treatments with five replicates of thirty fish per tank. The results showed that the supplementation of 1000 Da and 3000 Da COS significantly improved the growth performance and feed utilization in GIFT tilapia. The trend of decreasing total cholesterol, triglyceride, ALT, and ACP activity was observed in fish fed diet supplemented COS. The supplementation of 1000 Da and 3000 Da COS significantly improved the serum TAC activity, and decreased the serum MDA and catalase activities (P < 0.05). The lysozyme activity of blood, liver, and gills in fish fed diets supplemented with 1000 Da and 3000 Da COS was significantly higher than that of fish fed control diet after 56 days of feeding (P < 0.05). The phagocytic activity and phagocytic index of fish fed diets supplemented with 1000 Da and 3000 Da COS were significantly higher than those of fish fed control diet. Post-challenge test showed that fish mortality in 1000 Da, 3000 Da, and 8000 Da COS groups were significantly lower than that of fish in control group (P < 0.05). In conclusion, the present study indicated that dietary 1000 Da and 3000 Da COS supplementation could enhance more performance and immune response of GIFT tilapia than 8000 Da COS.


Assuntos
Antioxidantes/metabolismo , Ciclídeos/imunologia , Resistência à Doença/efeitos dos fármacos , Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Oligossacarídeos/metabolismo , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Ciclídeos/crescimento & desenvolvimento , Dieta/veterinária , Suplementos Nutricionais/análise , Resistência à Doença/imunologia , Relação Dose-Resposta a Droga , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Imunidade Inata/imunologia , Oligossacarídeos/administração & dosagem
14.
Fish Shellfish Immunol ; 93: 463-473, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31374316

RESUMO

To investigate the effects of arginine (Arg) on the growth, antioxidant capacity, immunity and disease resistance of juvenile Chinese mitten crab, three diets containing Arg levels at 1.72% (control), 2.73% and 3.72% were formulated and fed to Chinese mitten crab (0.22 ±â€¯0.03 g) for eight weeks. The weight gain, ecdysterone and growth hormone in the serum, relative expression of insulin-like growth factor 2 in the hepatopancreas significantly increased in crabs fed the 2.73% and 3.72% Arg diets. The protein and lipid contents significantly increased in crabs fed the 3.72% Arg diet. The feed conversion ratios in crabs fed the diets with Arg additions were lower than in the control. Arg supplementation also enhanced the antioxidative capacity by increasing the activities of superoxide dismutase, catalase and the relative expression of Kelch-like ECH-associated protein 1 gene in the hepatopancreas, which subsequently decreased malondialdehyde content in the hepatopancreas. Besides, Arg also decreased nitric oxide content in the serum and the activity of nitric oxide synthetase in the hepatopancreas. The relative mRNA levels of crustin, relish, lysozyme and cryptocyanin genes were significantly upregulated by Arg supplementation. The activities of acid phosphatase and alkaline phosphatase in the serum significantly increased in crabs fed the 3.72% Arg diet than those in the control. Similarly, the relative mRNA levels of crustin, cryptocyanin and proPO genes were significantly upregulated in crabs fed the 2.73% Arg diet after lipopolysaccharide challenge, and in crabs fed the 3.72% Arg diet after the Poly (I:C) challenge. The crabs fed the 2.73% and 3.72% Arg diets had higher survival rate after bacterial infection than those fed the control diet. This study indicates that the addition of Arg to the diet at 2.7-3.7% can improve the growth, survival, antioxidant capacity, immunity and disease resistance in juvenile Chinese mitten crab.


Assuntos
Arginina/metabolismo , Braquiúros/imunologia , Resistência à Doença/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Ração Animal/análise , Animais , Arginina/administração & dosagem , Braquiúros/efeitos dos fármacos , Braquiúros/crescimento & desenvolvimento , Braquiúros/metabolismo , Dieta/veterinária , Suplementos Nutricionais/análise , Imunidade Inata/imunologia , Distribuição Aleatória
15.
Food Chem ; 301: 125303, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31387045

RESUMO

The effects of exogenous polyamines treatment on reactive oxygen species (ROS) metabolism in apricot fruits were systematically analyzed through the investigation of their curative and preventive effects on black spot disease. Results showed that 1.5 mM spermine (Spm), 1.5 mM spermidine (Spd) and 10 mM putrescine (Put) treatment significantly inhibited black spot development, additionally, the efficacy of this control was dependent upon the type of polyamines used and concentration level applied. Further studies have shown that exogenous polyamines treatments significantly improved production of O2- and H2O2, and increased the activities and gene expression levels of NADPH oxidase (NOX), super oxide dismutase (SOD), catalase (CAT) ascorbate peroxidase (AXP) and glutathione reductase (GR) in apricot fruit. Increased ascorbic acid (AsA) and reduced glutathione (GSH) content were also observed after exogenous polyamines treatment. These results have revealed that postharvest polyamines treatment effectively enhanced disease resistance through the maintenance of homeostasis in apricot fruits.


Assuntos
Alternaria/patogenicidade , Frutas/efeitos dos fármacos , Doenças das Plantas/microbiologia , Poliaminas/farmacologia , Prunus armeniaca/efeitos dos fármacos , Ascorbato Peroxidases/metabolismo , Catalase/metabolismo , Resistência à Doença/efeitos dos fármacos , Frutas/metabolismo , Frutas/microbiologia , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Homeostase/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Oxirredução , Prunus armeniaca/metabolismo , Prunus armeniaca/microbiologia , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
16.
Fish Shellfish Immunol ; 93: 917-923, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31430560

RESUMO

This study investigated the effect of the dietary supplementation of bovine lactoferrin (LF) on growth performance, hematological and immunological parameters, antioxidant enzymes activity and disease resistance against Vibrio harveyi in yellowfin sea bream (Acanthopagrus latus) fingerling. The fish with initial body weight 10 ±â€¯0.3 g were randomly distributed at 10 fish per each 250 L fiberglass tank, and fed with four experimental diets (a control basal diet and three supplemented diets with 400, 800 and 1200 mg LF kg-1 diet) for 8 weeks. The obtained results showed that fish fed with LF supplemented diets had significantly higher final body weight as compared to control diet (P < 0.05). There were no significant differences between LF-treatments and the control group in white blood cell counts, red blood cell counts, hemoglobin and hematocrit. Total protein and complement activity (ACH50) in the serum of yellowfin sea bream were enhanced with increasing the dietary LF supplementation level (P < 0.05). The mucus lysozyme activity in fish fed on 800 and 1200 mg LF kg-1 was significantly higher than those fed on 400 mg LF kg-1 and control fish (P < 0.05). None of the antioxidant enzymes (catalase, glutathione reductase, glutathione S-transferase) was affected by LF supplementation (P > 0.05). Fish fed with dietary LF had a significantly higher survival rate than those fed with the control diet after challenge with Vibrio harveyi (P < 0.05). These results revealed that diet supplementation in A. latus especially with 1200 mg LF kg-1 improve fish growth performance and immune parameters, as well as survival rate against Vibrio harveyi.


Assuntos
Antioxidantes/metabolismo , Suplementos Nutricionais , Resistência à Doença/efeitos dos fármacos , Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Lactoferrina/farmacologia , Dourada/imunologia , Adjuvantes Imunológicos/farmacologia , Ração Animal/análise , Animais , Dieta/veterinária , Relação Dose-Resposta a Droga , Distribuição Aleatória , Dourada/sangue , Dourada/crescimento & desenvolvimento , Vibrio/fisiologia , Vibrioses/imunologia , Vibrioses/veterinária
17.
Mol Plant Microbe Interact ; 32(11): 1475-1486, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31298967

RESUMO

Plant activators, including acibenzolar-S-methyl (ASM), are chemical compounds that stimulate plant defense responses to pathogens. ASM treatment inhibits infection by a variety of plant viruses, however, the mechanisms of this broad-spectrum and strong effect remain poorly understood. We employed green fluorescent protein (GFP)-expressing viruses and Nicotiana benthamiana plants to identify the infection stages that are restricted by ASM. ASM suppressed infection by three viral species, plantago asiatica mosaic virus (PlAMV), potato virus X (PVX), and turnip mosaic virus (TuMV), in inoculated cells. Furthermore, ASM delayed the long-distance movement of PlAMV and PVX, and the cell-to-cell (short range) movement of TuMV. The ASM-mediated delay of long-distance movement of PlAMV was not due to the suppression of viral accumulation in the inoculated leaves, indicating that ASM restricts PlAMV infection in at least two independent steps. We used Arabidopsis thaliana mutants to show that the ASM-mediated restriction of PlAMV infection requires the NPR1 gene but was independent of the dicer-like genes essential for RNA silencing. Furthermore, experiments using protoplasts showed that ASM treatment inhibited PlAMV replication without cell death. Our approach, using GFP-expressing viruses, will be useful for the analysis of mechanisms underlying plant activator-mediated virus restriction.


Assuntos
Potexvirus , Tiadiazóis , Tabaco , Adjuvantes Imunológicos/farmacologia , Resistência à Doença/efeitos dos fármacos , Imunidade Vegetal/efeitos dos fármacos , Potexvirus/fisiologia , Tiadiazóis/farmacologia , Tabaco/imunologia , Tabaco/virologia
18.
Fish Shellfish Immunol ; 92: 913-924, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31306761

RESUMO

A feeding trial was performed to compare the effects of five ethanol herbal extracts (bhumi amla, Phyllanthus amarus Schum and Thonn [Pa]; guava, Psidium guajava L. [Pg]; sensitive plant, Mimosa pudica L. [Mp]; neem, Azadirachta indica A. Juss [Ai] and asthma plant, Euphorbia hirta L. [Eh]) on the immune response and disease resistance against Edwardsiella ictaluri infection of striped catfish (Pangasianodon hypophthalmus). Fish were fed diets supplemented with two doses of each plant extract (0% [basal diet], 0.4% Eh [Eh0.4], 2.0% Eh [Eh2.0], 0.2% Pa [Pa0.2], 1.0% Pa [Pa1.0], 0.2% Pg [Pg0.2], 1.0% Pg [Pg1.0], 0.4% Mp [Mp0.4], 2.0% Mp [Mp2.0], 0.4% Ai [Ai0.4], 2.0% Ai [Ai2.0]) for 8 weeks. Results showed that hematological parameters (total red blood cells, white blood cells, lymphocytes, monocytes, and neutrophils) of fish fed extract-based diets were significantly higher than in those fed the control diet (p < 0.05) after 4 and 8 weeks. Plasma lysozyme activity increased in fish whose diets contained both doses of Eh (p < 0.05) in week 4 (W4), whereas lysozyme activity increased in fish fed 0.2% Pa and Pg, and 2.0% Ai and Eh (p < 0.05) in week 8 (W8). The lysozyme levels in skin mucus did not significantly differ between treatments (p > 0.05) in W4 and after the bacterial challenge test. At the end of the feeding trial, levels of ACH50 significantly increased in most of extract groups compared to the control group (p < 0.05). Total immunoglobulin increased considerably in both the plasma and skin mucus of fish fed extract-supplemented diets after 8 weeks. In addition, dietary supplementation with Pg, Mp, Pa0.2, Eh2.0, and Ai0.4 for 8 weeks considerably reduced the cumulative mortality against E. ictaluri infection in striped catfish. The results suggest that plant extracts possibly modulate the striped catfish immune response in a time and dose dependent manner. Specifically, diets enriched with extracts of P. guajava at 0.2 and 1.0%, or M. pudica at 2.0% for 8 weeks, have great potential for improving striped catfish health by enhancing the immune system and reducing mortality against bacterial challenges.


Assuntos
Imunidade Adaptativa/efeitos dos fármacos , Peixes-Gato/imunologia , Resistência à Doença/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Extratos Vegetais/metabolismo , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Edwardsiella ictaluri/fisiologia , Infecções por Enterobacteriaceae/imunologia , Doenças dos Peixes/imunologia , Extratos Vegetais/administração & dosagem , Distribuição Aleatória
19.
Phytopathology ; 109(12): 2033-2045, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31294680

RESUMO

The induction of plant defense mechanisms by resistance inducers is an attractive and innovative alternative to reduce the use of fungicides on wheat against Zymoseptoria tritici, the responsible agent of Septoria tritici blotch (STB). Under controlled conditions, we investigated the resistance induction in three wheat cultivars with different susceptible levels to STB as a response to a treatment with a sulfur, manganese sulfate, and protein-based resistance inducer (NECTAR Céréales). While no direct antigermination effect of the product was observed in planta, more than 50% reduction of both symptoms and sporulation were recorded on the three tested cultivars. However, an impact of the wheat genotype on resistance induction was highlighted, which affects host penetration, cell colonization, and the production of cell-wall degrading enzymes by the fungus. Moreover, in the most susceptible cultivar Alixan, the product upregulated POX2, PAL, PR1, and GLUC gene expression in both noninoculated and inoculated plants and CHIT2 in noninoculated plants only. In contrast, defense responses induced in Altigo, the most resistant cultivar, seem to be more specifically mediated by the phenylpropanoid pathway in noninoculated as well as inoculated plants, since PAL and CHS were most specifically upregulated in this cultivar. In Premio, the moderate resistant cultivar, NECTAR Céréales elicits mainly the octadecanoid pathway, via LOX and AOS induction in noninoculated plants. We concluded that this complex resistance-inducing product protects wheat against Z. tritici by stimulating the cultivar-dependent plant defense mechanisms.


Assuntos
Ascomicetos , Fertilizantes , Nutrientes , Triticum , Ascomicetos/fisiologia , Resistência à Doença/efeitos dos fármacos , Fungicidas Industriais , Nutrientes/farmacologia , Doenças das Plantas/microbiologia , Triticum/efeitos dos fármacos , Triticum/microbiologia
20.
Fish Shellfish Immunol ; 93: 726-731, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31265912

RESUMO

Application of traditional bait in aquaculture caused environment pollution and disease frequent occurrence. Residual coconut could be re-utilized to culture Spinibarbus sinensis as dietary supplement. Therefore, a novel integrated system of the improvement of yield, antioxidant and nonspecific immunity of Spinibarbus sinensis by dietary residual coconut was proposed and investigated. Spinibarbus sinensis could grow well in all supplement residual coconut groups. Survival rate, yield, whole fish body composition under 15-45% groups were increased compared with control group (CK). Bioactive substances (polyphenols and vitamin) in residual coconut enhanced AKP, ACP, phagocytic, SOD, CAT activities through up-regulating AKP, ACP, SOD, CAT genes expression levels. Theoretical analysis showed bioactive substances regulated these genes expressions and enzyme activities as stimulus signal, component, active center. Moreover, residual coconut improved mTOR and NF-kB signaling pathway. Furthermore, residual coconut inhibited Aeromonas hydrophila that increased resistance to diseases. This technology completed the solid waste recovery and the Spinibarbus sinensis culture simultaneously.


Assuntos
Antioxidantes/metabolismo , Óleo de Coco/metabolismo , Cyprinidae/imunologia , Resistência à Doença/imunologia , Imunidade Inata/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Ração Animal/análise , Animais , Aquicultura/métodos , Óleo de Coco/administração & dosagem , Cyprinidae/crescimento & desenvolvimento , Cyprinidae/metabolismo , Dieta/veterinária , Suplementos Nutricionais/análise , Resistência à Doença/efeitos dos fármacos , Relação Dose-Resposta a Droga , Estudos de Viabilidade
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