[Objective]The aim of this study was to investigate whether communication signal C6-HSL among individual bacteria can influence plant growth and disease resistance ability. [Method]With potato virus-free plantlets as ...[Objective]The aim of this study was to investigate whether communication signal C6-HSL among individual bacteria can influence plant growth and disease resistance ability. [Method]With potato virus-free plantlets as the test materials and C6-HSL as the inducer,the potato＇s growth and the ability of resistance against Erwinia carotovora subp carotovora were tested after being treated by C6-HSL with different concentrations. The effects of C6-HSL on plant landmark defense enzyme activities and H2O2 content in potato leaves were measured especially. [Result]C6-HSL with different concentrations could obviously inhibit the growth rate of root and the number of roots,but had no effect on plant height,number of nodes and leaf size. POD or SOD activity and H2O2 content in plant landmark defense enzymes significantly increased after induction of C6-HSL,but PAL and PPO activity had no obvious change. In the resistant test,potato plants induced by C6-HSL could inhibit the infection of Erwinia carotovora subp carotovora effectively,and its incidence was significantly lower than the control group. [Conclusion]Bacteria AHL can be possibly used as a new kind of plant disease-resistant activator.展开更多
The Chinese Dream in Full Swing Speech Extracts from the International Dialogue on the Chinese Dream ForumCHINA was the center of human civilization for hundreds of years.During its long history,it became used to impl...The Chinese Dream in Full Swing Speech Extracts from the International Dialogue on the Chinese Dream ForumCHINA was the center of human civilization for hundreds of years.During its long history,it became used to implementing defensive strategies externally while developing the country internally.展开更多
Amphioxus is an important animal model for phylogenetic analysis,including comparative immunology.Exploring the immune system in amphioxus contributes to our understanding of the origin and evolution of the vertebrate...Amphioxus is an important animal model for phylogenetic analysis,including comparative immunology.Exploring the immune system in amphioxus contributes to our understanding of the origin and evolution of the vertebrate immune system.We investigated the amphioxus immune system using ultrastructural examination and in situ hybridization.The expression patterns of TLR1(toll-like receptor 1),C1Q(complement component 1,q subcomponent),ECSIT(evolutionarily conserved signaling intermediate in Toll pathways),SoxC,DDAHa(Dimethylarginine dimethylaminohydrolase a),and NOS(nitric oxide synthase) show that these genes play key roles in amphioxus immunity.Our results suggest that the epidermis and alimentary canal epithelium may play important roles in immune defense,while macrophages located in the coelom and so-called lymph spaces may also be crucial immune cells.展开更多
Defensins play a vital role in the early stage of infection before adaptive immune responses are generated. Thus far, only limited detailed genomic data for avian defensin genes have been described. Here, using bacter...Defensins play a vital role in the early stage of infection before adaptive immune responses are generated. Thus far, only limited detailed genomic data for avian defensin genes have been described. Here, using bacterial ar- tificial chromosome libraries, we found that a 95 kb and 177 kb sequences in the golden pheasant （Chrysolophus pictus, Galliformes） and hwamei （Garrulax canorus, Passeriformes） corresponds to 16 and 30 defensin genes, respectively. Fluorescence in situ hybridization assigned defensin gene clusters in the golden pheasant and hwamei to chromosomes 2q and 3q, respectively. In combination with the previous chicken （Gallus gallus, Galliformes） and zebra finch （Taeniopygia guttata, Passeriformes） defensin clusters, the comparative genomic analysis revealed that lineage- specific duplications and deletions have given rise to clearly different genomic structures. On the basis of genomic char- acteristics, we further found that transposable elements act as agents of evolution, causing direct and indirect copy number variations in defensin genes via duplications. Tissue ex- pression analysis showed that the Passeriformes-specific duplicated AvBD1 and AvBD3 genes are mainly expressed in the upper and lower respiratory tract, tongue, and spleen. Our analyses indicate that the duplication-and-deletion of defensin genes conformed to the birth-and-death evolutionary process and that transposable elements induced theduplication of defensin genes. Moreover, the respiratory system-specific expression pattern of Passeriformes-specific expanded AvBD1 and AvBD3 genes suggests their important role in maintaining the singing trait of songbirds. The understanding of the genomic structure, expression, and evolution of defensin genes can provide a crucial immunological foundation to study and prevent avian diseases.展开更多
基金Supported by Natural Science Foundation in Hebei Province(C200600707)~~
文摘[Objective]The aim of this study was to investigate whether communication signal C6-HSL among individual bacteria can influence plant growth and disease resistance ability. [Method]With potato virus-free plantlets as the test materials and C6-HSL as the inducer,the potato＇s growth and the ability of resistance against Erwinia carotovora subp carotovora were tested after being treated by C6-HSL with different concentrations. The effects of C6-HSL on plant landmark defense enzyme activities and H2O2 content in potato leaves were measured especially. [Result]C6-HSL with different concentrations could obviously inhibit the growth rate of root and the number of roots,but had no effect on plant height,number of nodes and leaf size. POD or SOD activity and H2O2 content in plant landmark defense enzymes significantly increased after induction of C6-HSL,but PAL and PPO activity had no obvious change. In the resistant test,potato plants induced by C6-HSL could inhibit the infection of Erwinia carotovora subp carotovora effectively,and its incidence was significantly lower than the control group. [Conclusion]Bacteria AHL can be possibly used as a new kind of plant disease-resistant activator.
文摘The Chinese Dream in Full Swing Speech Extracts from the International Dialogue on the Chinese Dream ForumCHINA was the center of human civilization for hundreds of years.During its long history,it became used to implementing defensive strategies externally while developing the country internally.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30570967, 30671072 and 30700434)Natural Science Foundation of Shandong Province (Grant No. Y2007D20)Ministry of Science and Technology of China (Grant Nos. 2007CB815800 and 2007CB947100)
文摘Amphioxus is an important animal model for phylogenetic analysis,including comparative immunology.Exploring the immune system in amphioxus contributes to our understanding of the origin and evolution of the vertebrate immune system.We investigated the amphioxus immune system using ultrastructural examination and in situ hybridization.The expression patterns of TLR1(toll-like receptor 1),C1Q(complement component 1,q subcomponent),ECSIT(evolutionarily conserved signaling intermediate in Toll pathways),SoxC,DDAHa(Dimethylarginine dimethylaminohydrolase a),and NOS(nitric oxide synthase) show that these genes play key roles in amphioxus immunity.Our results suggest that the epidermis and alimentary canal epithelium may play important roles in immune defense,while macrophages located in the coelom and so-called lymph spaces may also be crucial immune cells.
基金supported by the National Natural Science Foundation of China(31070334)
文摘Defensins play a vital role in the early stage of infection before adaptive immune responses are generated. Thus far, only limited detailed genomic data for avian defensin genes have been described. Here, using bacterial ar- tificial chromosome libraries, we found that a 95 kb and 177 kb sequences in the golden pheasant （Chrysolophus pictus, Galliformes） and hwamei （Garrulax canorus, Passeriformes） corresponds to 16 and 30 defensin genes, respectively. Fluorescence in situ hybridization assigned defensin gene clusters in the golden pheasant and hwamei to chromosomes 2q and 3q, respectively. In combination with the previous chicken （Gallus gallus, Galliformes） and zebra finch （Taeniopygia guttata, Passeriformes） defensin clusters, the comparative genomic analysis revealed that lineage- specific duplications and deletions have given rise to clearly different genomic structures. On the basis of genomic char- acteristics, we further found that transposable elements act as agents of evolution, causing direct and indirect copy number variations in defensin genes via duplications. Tissue ex- pression analysis showed that the Passeriformes-specific duplicated AvBD1 and AvBD3 genes are mainly expressed in the upper and lower respiratory tract, tongue, and spleen. Our analyses indicate that the duplication-and-deletion of defensin genes conformed to the birth-and-death evolutionary process and that transposable elements induced theduplication of defensin genes. Moreover, the respiratory system-specific expression pattern of Passeriformes-specific expanded AvBD1 and AvBD3 genes suggests their important role in maintaining the singing trait of songbirds. The understanding of the genomic structure, expression, and evolution of defensin genes can provide a crucial immunological foundation to study and prevent avian diseases.
