Phytohormones play a crucial role in regulating peanut growth and development.Our previous studies have demonstrated that the microbial inoculant ARC-BBBE,developed by our research group,effectively promotes peanut gr...Phytohormones play a crucial role in regulating peanut growth and development.Our previous studies have demonstrated that the microbial inoculant ARC-BBBE,developed by our research group,effectively promotes peanut growth and enhances yield under both greenhouse and field conditions.Therefore,it is of significant interest to investigate how ARC-BBBE influences the levels and spatial distribution of major phytohormones in peanut roots.Greenhouse pot experiments revealed that ARC-BBBE significantly enhanced peanut growth and root system development.A systematic analysis of the effects of ARC-BBBE on key phytohormones in peanut roots across different growth stages showed that gibberellin A_(3)(GA_(3))content varied markedly,with predominant accumulation occurring during the early growth stage,whereas changes in indole-3-acetic acid(IAA)levels were not statistically significant.Specifically,GA_(3)content in the ARC-BBBE treatment group was 1.27-fold higher than in the control group during the seedling stage.Furthermore,peanut growth parameters were significantly improved following ARC-BBBE application,particularly at the flowering stage,where plant height,above-ground biomass,root length,and root weight in the treated group were 1.24-,1.17-,1.13-,and 1.21-fold greater than those in the control,respectively.To elucidate the functional role of phytohormones in ARC-BBBE-mediated growth promotion,we examined the effects of exogenous GA_(3)and its biosynthesis inhibitor uniconazole(S3307)on both PHNZY-23-3 rhizobial growth and peanut development.Results indicated that supplementation with 1×10~3 mg/L GA_(3)most effectively promoted peanut growth at the seedling stage,while S3307 application inhibited growth.These findings provide valuable insights into the mechanism by which ARC-BBBE modulates GA_(3)dynamics to enhance peanut growth,offering a foundation for future research on plant-microbe interactions and phytohormone regulation.展开更多
Ohjective To review the clinical features and laboratory investigations of ciguatera patients in Hong Kong between 2004 and 2007 in order to show the timely sampling of implicated fish from ciguatera victims and appli...Ohjective To review the clinical features and laboratory investigations of ciguatera patients in Hong Kong between 2004 and 2007 in order to show the timely sampling of implicated fish from ciguatera victims and application of validated mouse bioassay for confirming suspected clinical cases of ciguatera. Methods Diagnosis of the ciguatera victims was based on history of coral fish consumption and clinical presentations stated in official guidelines for clinical diagnosis of ciguatera fish poisoning in Hong Kong. Food remnants of coral fish samples were collected swiftly from ciguatera victims between 2004 and 2007 for ciguatoxins （CTXs） analysis. Results Major clinical symptoms in ciguatera patients included gastrointestinal and neurological effects including limb numbness and diarrhoea, which developed at 0.5 to 15 hours after consumption of fish. In most cases, neurological symptoms were more common than gastrointestinal symptoms. A broad range of attack rate （10%-100%） was observed in each ciguatera outbreak. Validated mouse bioassay on ether extracts of the food remnant samples confirmed that all were CTXs-positive （〈0.5 - 4.3 MU/20 mg ether extract） and directly linked to the corresponding ciguatera cases. Conclusion Consistency between clinical and laboratory analysis for ciguatera poisoning illustrates the application of laboratory mouse bioassay in a timely fashion for confirming ciguatera poisoning cases and implementing effective public health measures. With further improvement in laboratory techniques, features of ciguatera fish poisoning cases can be better defined, Further studies are needed to determine the risk of each class of CTXs （Pacific-, Indian- and Caribbean-CTXs） in Hong Kong.展开更多
Objective To develop an ICR （female） mouse bioassay （MBA） for toxicity confirmation and evaluation of neurotoxins （brevetoxins）-contaminated shellfish. Methods Brevetoxins （BTX-B） as a causative agent of neuro...Objective To develop an ICR （female） mouse bioassay （MBA） for toxicity confirmation and evaluation of neurotoxins （brevetoxins）-contaminated shellfish. Methods Brevetoxins （BTX-B） as a causative agent of neurotoxic shellfish poisoning （NSP） under different shellfish matrices were intraperitoneally injected at different doses into mice to study their toxic effects and to differentiate the range of lethal and sublethal dosages. Their sensitivity and specificity were analyzed with 2 competitive ELISA kits for quantitative determination of standard BTX-B and dihydroBTX-B under different shellfish matrix-diluent combinations. Detection rates of MBA and two antibody-based assays for BTX-B from field NSP-positive shellfish samples were compared. Results BTX-B could be detected in shellfish tissues at concentration of 50-400 μg/100 g under shellfish matrix-Tween-saline media, which were appropriate to identify toxic shellfish at or above the regulatory limit （80 μg/100 g shellfish tissues）. The LD 50 identified was 455 g/kg for BTX-B under general shellfish matrices （excluding oyster matrices） dissolved in Tween-saline. The presence of shellfish matrices, of oyster matrices in particular, retarded the occurrence of death and toxicity presentation in mice. Two antibody-based assays, even in the presence of different shellfish matrix-diluent combinations, showed acceptable results in quantifying BTX-B and dihydroBTX-B well below the regulatory limit. Conclusion The two ELISA analyses agree favorably （correlation coefficient, r 0.96; Student＇s t-tests, P〉0.05） with the developed bioassay.展开更多
基金financially supported by National Natural Science Foundation of China(No.32441047,32272447)Natural Science Foundation of Hubei Province(No.2022C FA 107)Central Publicinterest Scientific Institution Basal Research Fund for CAAS(No.1610172023001)。
文摘Phytohormones play a crucial role in regulating peanut growth and development.Our previous studies have demonstrated that the microbial inoculant ARC-BBBE,developed by our research group,effectively promotes peanut growth and enhances yield under both greenhouse and field conditions.Therefore,it is of significant interest to investigate how ARC-BBBE influences the levels and spatial distribution of major phytohormones in peanut roots.Greenhouse pot experiments revealed that ARC-BBBE significantly enhanced peanut growth and root system development.A systematic analysis of the effects of ARC-BBBE on key phytohormones in peanut roots across different growth stages showed that gibberellin A_(3)(GA_(3))content varied markedly,with predominant accumulation occurring during the early growth stage,whereas changes in indole-3-acetic acid(IAA)levels were not statistically significant.Specifically,GA_(3)content in the ARC-BBBE treatment group was 1.27-fold higher than in the control group during the seedling stage.Furthermore,peanut growth parameters were significantly improved following ARC-BBBE application,particularly at the flowering stage,where plant height,above-ground biomass,root length,and root weight in the treated group were 1.24-,1.17-,1.13-,and 1.21-fold greater than those in the control,respectively.To elucidate the functional role of phytohormones in ARC-BBBE-mediated growth promotion,we examined the effects of exogenous GA_(3)and its biosynthesis inhibitor uniconazole(S3307)on both PHNZY-23-3 rhizobial growth and peanut development.Results indicated that supplementation with 1×10~3 mg/L GA_(3)most effectively promoted peanut growth at the seedling stage,while S3307 application inhibited growth.These findings provide valuable insights into the mechanism by which ARC-BBBE modulates GA_(3)dynamics to enhance peanut growth,offering a foundation for future research on plant-microbe interactions and phytohormone regulation.
文摘Ohjective To review the clinical features and laboratory investigations of ciguatera patients in Hong Kong between 2004 and 2007 in order to show the timely sampling of implicated fish from ciguatera victims and application of validated mouse bioassay for confirming suspected clinical cases of ciguatera. Methods Diagnosis of the ciguatera victims was based on history of coral fish consumption and clinical presentations stated in official guidelines for clinical diagnosis of ciguatera fish poisoning in Hong Kong. Food remnants of coral fish samples were collected swiftly from ciguatera victims between 2004 and 2007 for ciguatoxins （CTXs） analysis. Results Major clinical symptoms in ciguatera patients included gastrointestinal and neurological effects including limb numbness and diarrhoea, which developed at 0.5 to 15 hours after consumption of fish. In most cases, neurological symptoms were more common than gastrointestinal symptoms. A broad range of attack rate （10%-100%） was observed in each ciguatera outbreak. Validated mouse bioassay on ether extracts of the food remnant samples confirmed that all were CTXs-positive （〈0.5 - 4.3 MU/20 mg ether extract） and directly linked to the corresponding ciguatera cases. Conclusion Consistency between clinical and laboratory analysis for ciguatera poisoning illustrates the application of laboratory mouse bioassay in a timely fashion for confirming ciguatera poisoning cases and implementing effective public health measures. With further improvement in laboratory techniques, features of ciguatera fish poisoning cases can be better defined, Further studies are needed to determine the risk of each class of CTXs （Pacific-, Indian- and Caribbean-CTXs） in Hong Kong.
文摘Objective To develop an ICR （female） mouse bioassay （MBA） for toxicity confirmation and evaluation of neurotoxins （brevetoxins）-contaminated shellfish. Methods Brevetoxins （BTX-B） as a causative agent of neurotoxic shellfish poisoning （NSP） under different shellfish matrices were intraperitoneally injected at different doses into mice to study their toxic effects and to differentiate the range of lethal and sublethal dosages. Their sensitivity and specificity were analyzed with 2 competitive ELISA kits for quantitative determination of standard BTX-B and dihydroBTX-B under different shellfish matrix-diluent combinations. Detection rates of MBA and two antibody-based assays for BTX-B from field NSP-positive shellfish samples were compared. Results BTX-B could be detected in shellfish tissues at concentration of 50-400 μg/100 g under shellfish matrix-Tween-saline media, which were appropriate to identify toxic shellfish at or above the regulatory limit （80 μg/100 g shellfish tissues）. The LD 50 identified was 455 g/kg for BTX-B under general shellfish matrices （excluding oyster matrices） dissolved in Tween-saline. The presence of shellfish matrices, of oyster matrices in particular, retarded the occurrence of death and toxicity presentation in mice. Two antibody-based assays, even in the presence of different shellfish matrix-diluent combinations, showed acceptable results in quantifying BTX-B and dihydroBTX-B well below the regulatory limit. Conclusion The two ELISA analyses agree favorably （correlation coefficient, r 0.96; Student＇s t-tests, P〉0.05） with the developed bioassay.
