Receptor proteins on the brush border membrane of the insect midgut epithelium are involved in the mode of action of insecticidal Cry proteins from Bacillus thuringiensis(Bt). Polycalin has been identified as a bindin...Receptor proteins on the brush border membrane of the insect midgut epithelium are involved in the mode of action of insecticidal Cry proteins from Bacillus thuringiensis(Bt). Polycalin has been identified as a binding protein of the Bt Cry1 Ac toxin in several Lepidoptera including Helicoverpa armigera, but its role in the action mechanism of Cry2 Aa is still unclear. In this study, we investigated the binding characteristics of polycalin from the midgut of H. armigera with Cry2 Aa and its role in the toxicity of Cry2 Aa. The results demonstrated that heterologously expressed H. armigera polycalin peptide could bind with Cry2 Aa with high affinity(K_d=32 nmol L^(–1)). The toxicity of Cry2 Aa decreased by 27% after H. armigera larvae ingested polycalin antisera. These results suggested that polycalin could be a potential functional receptor for Cry2 Aa, and it plays an important role in the susceptibility of H. armigera to Cry2 Aa.展开更多
To understand the mechanism of benzothiadiazole (BTH)-induced susceptible rubber clone resistance to powdery mildew on gene level, a differentially expressed cDNA library was constructed by suppression subtractive hyb...To understand the mechanism of benzothiadiazole (BTH)-induced susceptible rubber clone resistance to powdery mildew on gene level, a differentially expressed cDNA library was constructed by suppression subtractive hybridization (SSH) with rubber Reyan 7-33-97 clone. The constructed cDNA library was high integrity through detection of the critical processes of SSH, such as efficiency of adaptor connection, subtraction and conversion, as well as the type of recombinant genes. The positive rate was 99% after identification with random 400 white spots. The size of the cDNA clone inserted fragments was various but most in 400 bp - 1000 bp. There were 23 cDNA sequences matching the function of energy and basic metabolism, signal transduction, membrane and transport, secondary metabolism and so on after detection of the 42 positive clone sequences selected randomly from the cDNA library and comparison on nucleic acid sequences in Genbank. 7 ESTs were logged in Genbank and accession numbers were GW873071 and GW874604- GW874610. The results implicated that BTH could effectively induced rubber tree resistance to powdery mildew through increasing expresses of defense-related genes in leaves of rubber tree susceptible clone. It should provide a new approach for rubber disease management.展开更多
基金supported by the Key Project for Breeding Genetically Modified Organisms, China (2016ZX08011002)the National Natural Science Foundation of China (31621064)the Fundamental Research Funds for Central Non-profit Scientific Institution, China (Y2017JC34)
文摘Receptor proteins on the brush border membrane of the insect midgut epithelium are involved in the mode of action of insecticidal Cry proteins from Bacillus thuringiensis(Bt). Polycalin has been identified as a binding protein of the Bt Cry1 Ac toxin in several Lepidoptera including Helicoverpa armigera, but its role in the action mechanism of Cry2 Aa is still unclear. In this study, we investigated the binding characteristics of polycalin from the midgut of H. armigera with Cry2 Aa and its role in the toxicity of Cry2 Aa. The results demonstrated that heterologously expressed H. armigera polycalin peptide could bind with Cry2 Aa with high affinity(K_d=32 nmol L^(–1)). The toxicity of Cry2 Aa decreased by 27% after H. armigera larvae ingested polycalin antisera. These results suggested that polycalin could be a potential functional receptor for Cry2 Aa, and it plays an important role in the susceptibility of H. armigera to Cry2 Aa.
文摘To understand the mechanism of benzothiadiazole (BTH)-induced susceptible rubber clone resistance to powdery mildew on gene level, a differentially expressed cDNA library was constructed by suppression subtractive hybridization (SSH) with rubber Reyan 7-33-97 clone. The constructed cDNA library was high integrity through detection of the critical processes of SSH, such as efficiency of adaptor connection, subtraction and conversion, as well as the type of recombinant genes. The positive rate was 99% after identification with random 400 white spots. The size of the cDNA clone inserted fragments was various but most in 400 bp - 1000 bp. There were 23 cDNA sequences matching the function of energy and basic metabolism, signal transduction, membrane and transport, secondary metabolism and so on after detection of the 42 positive clone sequences selected randomly from the cDNA library and comparison on nucleic acid sequences in Genbank. 7 ESTs were logged in Genbank and accession numbers were GW873071 and GW874604- GW874610. The results implicated that BTH could effectively induced rubber tree resistance to powdery mildew through increasing expresses of defense-related genes in leaves of rubber tree susceptible clone. It should provide a new approach for rubber disease management.
