Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321&#...Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321' were transformed respectively by two efficient plant expression plasmids pBinMoBc and pBinoBc via Agrobacterium tumefaciens . In pBinMoBc, cry 1Ac3 gene, which encodes the Bt toxin, is under the control of chimeric OM promoter. In pBinoBc, it is under control of CaMV 35S promoter. After co_cultivation with Agrobacterium tumefimpfaciens LBA4404 (containing pBinMoBc or pBinoBc), kanamycin_resistant selection, somatic embryos were induced and regenerated plants were obtained. Then the regenerated plantlets were grafted to untransformed stocks in greenhouse to produce descendants. The integration of cry 1Ac3 gene and its expression in T 2 generation of transgenic cotton plants were confirmed by Southern hybridization and Western blotting. The analyses of insect bioassay indicated that the transgenic plants of both constructions have significant resistance to the larvae of cotton bollworm ( Heliothis armigera ) and that cry 1Ac3 gene driven by chimeric OM promoter could endue T 2 generation cotton with high pest_resistant ability, implicating that it has a profound application in genetic engineering to breed new pest_resistant cotton varieties.展开更多
Effects of transgenic Cry1Ac plus CpTI cotton(double genes cotton) on development of main parasitoids were studied in the laboratory.Compared with the traditional cotton,the differences of
A chimeric gene, Bt29K, composed of coding sequences of activated Cry1Ac insecticidal protein and an endoplasm reticulum-retarding signal peptide, was synthesized. A plant expression vector containing two expression c...A chimeric gene, Bt29K, composed of coding sequences of activated Cry1Ac insecticidal protein and an endoplasm reticulum-retarding signal peptide, was synthesized. A plant expression vector containing two expression cassettes for the Bt29K and API-B genes was constructed. These two insect-resistant genes were transferred into two cotton ( Gossypium hirsutum L.) varieties ( or lines) via Agrobacterium-mediated transformation and nine homozygous transgenic cotton lines showing a mortality of 90.0% - 99.7% to cotton ballworm (Heliothis armigera) larvae and good agronomic traits were selected through six generations. Molecular biology analysis revealed that one or two copies of the insecticidal protein genes were integrated into the transgenic cotton genome and activated Cry1Ac and API-B protein expression was at a level of 0.17% and 0.09% of the total soluble protein in the transgenic cotton leaves, respectively. Comparison of the insect-resistance of the homozygous lines expressing the activated chimeric Cry1Ac and API-B with that expressing Cry1Ac only revealed that the insect-resistance of the former is apparently higher than the latter. These results also indicate that the strategy to construct a plant expression vector expressing two different insect-resistant genes reported here is reasonable.展开更多
The effect of transgenic double genes, Cry1A + CpTI cotton and Cry1Ac toxinon the parasitoid, Campoketis chlorideae Uchida of cotton bollworm, Helicoverpa armigera (Huebner),was investigated in the laboratory. Helicov...The effect of transgenic double genes, Cry1A + CpTI cotton and Cry1Ac toxinon the parasitoid, Campoketis chlorideae Uchida of cotton bollworm, Helicoverpa armigera (Huebner),was investigated in the laboratory. Helicoverpa armigera larvae when in the first, second and thirdinstar could not survive if fed on transgenic cotton leaves. Consequently, C. chlorideae larvaecould not complete their development if parasitizing on such hosts. After H. armigera larvae werereared on transgenic or traditional cotton leaves for 12-48 hours, they were parasitized by C.chlorideae females. Parasitized larvae continued to feed on transgenic or traditional cotton for12-48 h. The present results showed that the body weight of larvae of the parasitoids weresignificantly reduced when parasitized hosts fed on transgenic cotton leaves compared to those fedon traditional cotton. Duration of egg and larvae stage were significantly prolonged, pupal andadult weight of C. chloridae was decreased when the host larvae fed on transgenic cotton leaveslonger than 48 h. The development duration of C. chlorideae pupae on the hosts fed on transgeniccotton leaves in each treatment was not significantly different from those of controls. Thelongevity of parasitoid females and males fed with a solution containing Cry1Ac toxin was notsignificantly different with that of the control.展开更多
文摘Hypocotyl segments from aseptic seedlings of two important cultivars of upland cotton ( Gossypium hirsutum L.) in Northwest China, 'Xinluzao_1', 'Jinmian_7', 'Jinmian_12' and 'Jihe_321' were transformed respectively by two efficient plant expression plasmids pBinMoBc and pBinoBc via Agrobacterium tumefaciens . In pBinMoBc, cry 1Ac3 gene, which encodes the Bt toxin, is under the control of chimeric OM promoter. In pBinoBc, it is under control of CaMV 35S promoter. After co_cultivation with Agrobacterium tumefimpfaciens LBA4404 (containing pBinMoBc or pBinoBc), kanamycin_resistant selection, somatic embryos were induced and regenerated plants were obtained. Then the regenerated plantlets were grafted to untransformed stocks in greenhouse to produce descendants. The integration of cry 1Ac3 gene and its expression in T 2 generation of transgenic cotton plants were confirmed by Southern hybridization and Western blotting. The analyses of insect bioassay indicated that the transgenic plants of both constructions have significant resistance to the larvae of cotton bollworm ( Heliothis armigera ) and that cry 1Ac3 gene driven by chimeric OM promoter could endue T 2 generation cotton with high pest_resistant ability, implicating that it has a profound application in genetic engineering to breed new pest_resistant cotton varieties.
文摘Effects of transgenic Cry1Ac plus CpTI cotton(double genes cotton) on development of main parasitoids were studied in the laboratory.Compared with the traditional cotton,the differences of
文摘A chimeric gene, Bt29K, composed of coding sequences of activated Cry1Ac insecticidal protein and an endoplasm reticulum-retarding signal peptide, was synthesized. A plant expression vector containing two expression cassettes for the Bt29K and API-B genes was constructed. These two insect-resistant genes were transferred into two cotton ( Gossypium hirsutum L.) varieties ( or lines) via Agrobacterium-mediated transformation and nine homozygous transgenic cotton lines showing a mortality of 90.0% - 99.7% to cotton ballworm (Heliothis armigera) larvae and good agronomic traits were selected through six generations. Molecular biology analysis revealed that one or two copies of the insecticidal protein genes were integrated into the transgenic cotton genome and activated Cry1Ac and API-B protein expression was at a level of 0.17% and 0.09% of the total soluble protein in the transgenic cotton leaves, respectively. Comparison of the insect-resistance of the homozygous lines expressing the activated chimeric Cry1Ac and API-B with that expressing Cry1Ac only revealed that the insect-resistance of the former is apparently higher than the latter. These results also indicate that the strategy to construct a plant expression vector expressing two different insect-resistant genes reported here is reasonable.
文摘The effect of transgenic double genes, Cry1A + CpTI cotton and Cry1Ac toxinon the parasitoid, Campoketis chlorideae Uchida of cotton bollworm, Helicoverpa armigera (Huebner),was investigated in the laboratory. Helicoverpa armigera larvae when in the first, second and thirdinstar could not survive if fed on transgenic cotton leaves. Consequently, C. chlorideae larvaecould not complete their development if parasitizing on such hosts. After H. armigera larvae werereared on transgenic or traditional cotton leaves for 12-48 hours, they were parasitized by C.chlorideae females. Parasitized larvae continued to feed on transgenic or traditional cotton for12-48 h. The present results showed that the body weight of larvae of the parasitoids weresignificantly reduced when parasitized hosts fed on transgenic cotton leaves compared to those fedon traditional cotton. Duration of egg and larvae stage were significantly prolonged, pupal andadult weight of C. chloridae was decreased when the host larvae fed on transgenic cotton leaveslonger than 48 h. The development duration of C. chlorideae pupae on the hosts fed on transgeniccotton leaves in each treatment was not significantly different from those of controls. Thelongevity of parasitoid females and males fed with a solution containing Cry1Ac toxin was notsignificantly different with that of the control.
