fructooligosaccharide and Disease-Resistance

This study aimed to determine the effects of fructooligosaccharide (FOS) levels and its feeding modes on growth, immune response, antioxidant capability and disease resistance of blunt snout bream (Megalobrama amblycephala). Fish (12.5 ± 0.5 g) were subjected to three FOS levels (0, 0.4% and 0.8%) and two feeding modes (supplementing FOS continuously and supplementing FOS two days interval 5 days) according to a 3 × 2 factorial design. At the end of 8-week feeding trial, fish were challenged by Aeromonas hydrophila with concentration of 1 × 10(5) CFU mL(-1) and mortality was recorded for the next 96 h. Fish fed 0.4% FOS continuously (D2) and fish fed the basal diet for 5 days followed by 0.8% FOS for 2 days (D5) showed admirable growth performance. The highest plasma lysozyme, acid phosphatase and myeloperoxidase activities as well as complement component 3, total protein and immunoglobulin M (IgM) levels were all observed in fish fed D5. They were significantly higher (P < 0.05) than those of the control group and/or fish fed 0.8% FOS continuously, but exhibited no statistical difference (P > 0.05) with that of fish fed D2. A similar trend was also observed in antioxidant capability as well as the expression of Leap-I and Leap-Ⅱ. Mortality showed an opposite trend with the immune response with the lowest rate observed in fish fed D5. The results indicated that diet supplementing FOS in appropriate levels and feeding modes could improve the growth, immune response and antioxidant capability of fish, as might consequently lead to enhanced disease resistance. It can be speculated that the basal diet for 5 days followed by 0.8% FOS for 2 days was most suitable for blunt snout bream.

Topics: Acid Phosphatase; Aeromonas hydrophila; Analysis of Variance; Animal Feed; Animals; Antioxidants; Aquaculture; Cyprinidae; Dietary Carbohydrates; Disease Resistance; DNA Primers; Dose-Response Relationship, Drug; Immunoglobulin M; Microscopy, Electron, Transmission; Muramidase; Oligosaccharides; Peroxidase; Real-Time Polymerase Chain Reaction

This study was conducted to investigate the effects of fructooligosaccharide (FOS) and Bacillus licheniformis (B. licheniformis) and their interaction on innate immunity, antioxidant capability and disease resistance of triangular bream Megalobrama terminalis (average initial weight 30.5 ± 0.5 g). Nine experimental diets were formulated to contain three FOS levels (0, 0.3% and 0.6%) and three B. licheniformis levels (0, 1 × 10(7), 5 × 10(7) CFU g(-1)) according to a 3 × 3 factorial design. At the end of the 8-week feeding trial, fish were challenged by Aeromonas hydrophila (A. hydrophila) and survival rate was recorded for the next 7 days. The results showed that leucocyte counts, alternative complement activity as well as total serum protein and globulin contents all increased significantly (P < 0.05) as dietary B. licheniformis levels increased from 0 to 1 × 10(7) CFU g(-1), while little difference (P > 0.05) was observed in these parameters in terms of dietary FOS levels. Both plasma alkaline phosphatase and phenoloxidase activities were significantly (P < 0.05) affected only by dietary FOS levels with the highest values observed in fish fed 0.6 and 0.3% FOS, respectively. Both immunoglobulin M content and liver superoxide dismutase (SOD) activity were significantly affected (P > 0.05) by both FOS and B. licheniformis. Liver catalase, glutathione peroxidase as well as plasma SOD activities of fish fed 1 × 10(7) CFU g(-1)B. licheniformis were all significantly (P < 0.05) higher than that of the other groups, whereas the opposite was true for malondialdehyde content. After A. hydrophila challenge, survival rate was not affected (P > 0.05) by either FOS levels or B. licheniformis contents, whereas a significant (P < 0.05) interaction between these two substances was observed with the highest value observed in fish fed 0.3% FOS and 1 × 10(7) CFU g(-1)B. licheniformis. The results of this study indicated that dietary FOS and B. licheniformis could significantly enhance the innate immunity and antioxidant capability of triangular bream, as well as improve its disease resistance. The best combination of these two prebiotics and/or probiotics was 0.3% FOS and 1 × 10(7) CFU g(-1)B. licheniformis.

Topics: Acid Phosphatase; Aeromonas hydrophila; Animals; Antioxidants; Aquaculture; Bacillus; Cyprinidae; Dietary Carbohydrates; Disease Resistance; Dose-Response Relationship, Drug; Immunity, Innate; Linear Models; Oligosaccharides; Survival Analysis

Burdock fructooligosaccharide (BFO), isolated from the roots of Arcitum lappa, is a novel potential elicitor. Previous studies have shown that BFO induces various defense responses in plants. However, little is known about the mechanism of BFO induced plant responses. The transcriptome profiles in tobacco leaves after treatment with BFO or distilled water were analyzed using Solexa technology. The profiling analysis revealed numerous changes in gene expression after BFO treatment, which resulted in the up-regulation of 169 genes and the down-regulation of 243 genes. The data were confirmed by reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR. Gene ontology analysis revealed that the differentially expressed genes were mainly involved in stress responses, defense responses, biosynthetic processes, hormone responses, RNA biosynthetic processes, signaling pathways and other processes. The results of this study suggested two important concepts. First, the differential expression of genes involved in plant hormone signaling pathways are related to defense, especially salicylic acid-mediated pathways, such as the genes encoding pathogen related proteins, WRKY transcription factors, Avr9/Cf-9 rapidly elicited protein, SA-activated MAP kinase, jasmonic acid/ethylene-related genes encoding jasmonate ZIM-domain protein and ethylene-responsive transcription factor, gibberellin-related genes encoding flowering promoting factor-like 1 and GA-insensitive dwarf 2, and abscisic acid related gene encoding ABA 8'-hydroxylase CYP707A, indicated that plant hormones and their crosstalk might play a critical role in the defense response to BFO treatment in tobacco. Second, the genes involved in the biosynthesis of secondary metabolites were increased after BFO treatment including epiaristolochene synthase and cinnamoyl-CoA reductase, which serve as attractants in defense against pathogens and herbivores.

Topics: Adaptation, Physiological; Asteraceae; Disease Resistance; Down-Regulation; Gene Expression Profiling; Gene Expression Regulation, Plant; Genes, Plant; Nicotiana; Oligosaccharides; Plant Diseases; Plant Roots; Signal Transduction; Stress, Physiological; Up-Regulation