TY - JOUR
T1 - Bacillus thuringiensis Cry11Ba works synergistically with Cry4Aa but not with Cry11Aa for toxicity against mosquito Culex pipiens (Diptera
T2 - Culicidae) larvae
AU - Hayakawa, Tohru
AU - Yoneda, Naoya
AU - Okada, Kouji
AU - Higaki, Ayuko
AU - Howlader, Mohammad Tofazzal Hossain
AU - Ide, Toru
N1 - Funding Information:
C. pipiens eggs were kindly supplied by the Research and Development Laboratory at Dainihon Jochugiku, Osaka. This work was supported by the Japan Society for the Promotion of Science KAKENHI (Grant Nos. JP24380034 and JP26660268).
Publisher Copyright:
© 2016, The Japanese Society of Applied Entomology and Zoology.
PY - 2017/2/1
Y1 - 2017/2/1
N2 - A 2,175-bp modified gene (cry11Ba-S1) encoding Cry11Ba from Bacillus thuringiensis subsp. jegathesan was designed and the recombinant protein was expressed as a fusion protein with glutathione S-transferase in Escherichia coli. The recombinant Cry11Ba was highly toxic against Culex pipiens mosquito larvae, being nine and 17 times more toxic than mosquitocidal Cry4Aa and Cry11Aa from Bacillus thuringiensis subsp. israelensis, respectively. Interestingly, a further increase in the toxicity of the recombinant Cry11Ba was achieved by mixing with Cry4Aa, but not with Cry11Aa. These findings suggested that Cry11Ba worked synergistically with Cry4Aa, but not with Cry11Aa, in exhibiting toxicity against C. pipiens larvae. On the other hand, the amount of Cry toxin bound to brush border membrane vesicles (BBMVs) did not significantly change between individual toxins and the toxin mixtures, suggesting that the increase in toxins binding to BBMVs was not a reason for the observed synergistic effect. It is generally accepted that synergism of toxins is a potentially powerful tool for enhancing insecticidal activity and managing Cry toxin resistance in mosquitoes. The mixture of Cry4Aa and Cry11Ba in order to increase toxicity would be very valuable in terms of mosquito control.
AB - A 2,175-bp modified gene (cry11Ba-S1) encoding Cry11Ba from Bacillus thuringiensis subsp. jegathesan was designed and the recombinant protein was expressed as a fusion protein with glutathione S-transferase in Escherichia coli. The recombinant Cry11Ba was highly toxic against Culex pipiens mosquito larvae, being nine and 17 times more toxic than mosquitocidal Cry4Aa and Cry11Aa from Bacillus thuringiensis subsp. israelensis, respectively. Interestingly, a further increase in the toxicity of the recombinant Cry11Ba was achieved by mixing with Cry4Aa, but not with Cry11Aa. These findings suggested that Cry11Ba worked synergistically with Cry4Aa, but not with Cry11Aa, in exhibiting toxicity against C. pipiens larvae. On the other hand, the amount of Cry toxin bound to brush border membrane vesicles (BBMVs) did not significantly change between individual toxins and the toxin mixtures, suggesting that the increase in toxins binding to BBMVs was not a reason for the observed synergistic effect. It is generally accepted that synergism of toxins is a potentially powerful tool for enhancing insecticidal activity and managing Cry toxin resistance in mosquitoes. The mixture of Cry4Aa and Cry11Ba in order to increase toxicity would be very valuable in terms of mosquito control.
KW - Biological control
KW - Cry toxin
KW - Disease vector
KW - Insect pest control
KW - Synergistic toxicity
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U2 - 10.1007/s13355-016-0454-z
DO - 10.1007/s13355-016-0454-z
M3 - Article
AN - SCOPUS:85011596116
VL - 52
SP - 61
EP - 68
JO - Applied Entomology and Zoology
JF - Applied Entomology and Zoology
SN - 0003-6862
IS - 1
ER -