Genetic engineering has created many genetically modified （GM） crop varieties that express the cry toxin from the bacterium Bacillus thuringiensis （Bt）. The cry toxin, synthesized during plant growth, has insectic...Genetic engineering has created many genetically modified （GM） crop varieties that express the cry toxin from the bacterium Bacillus thuringiensis （Bt）. The cry toxin, synthesized during plant growth, has insecticidal properties, and can be expressed anywhere in the plant. This study aimed to ascertain the richness and species diversity of edaphic Formicidae and Coleoptera in GM cotton fields compared with the conventional non-transformed cotton crop. We analyzed data from commercial cotton fields located in the municipality of Maracaju, Mato Grosso do Sul, Brazil. The experiment was conducted during the reproductive period of cotton, employed two treatments： Bt cotton and non-Bt cotton. Samples were collected with pitfall traps. Formicidae species richness in the Bt area was lower than in the non-Bt area, but species composition did not differ between the two treatments. Species composition of Coleoptera communities also differed between the treatments because some species were more abundant in the Bt cotton area. On the other hand, the species richness of this group was similar in both areas.展开更多
A promoter of the PNZIP （Pharbitis nil leucine zipper） gene （1.459 kb） was cloned from Pharbitis nil and fused to the GUS（^-glucuronidase） and Bacillus thuringiensis endotoxin （Cry9C） genes. Several transgenic...A promoter of the PNZIP （Pharbitis nil leucine zipper） gene （1.459 kb） was cloned from Pharbitis nil and fused to the GUS（^-glucuronidase） and Bacillus thuringiensis endotoxin （Cry9C） genes. Several transgenic PNZIP：：GUS and PNZIP：：Cry9C cotton lines were developed by Agrobacterium-mediated transformation. Strong GUS staining was detected in the green tissues of the transgenic PNZIP：：GUS cotton plants. In contrast, GUS staining in the reproductive structures such as petals, anther, and immature seeds of PNZIP：：GUS cotton was very faint. Two transgenic PNZIP：：Cry9C lines and one trans- genic cauliflower mosaic virus （CaMV） 35S：：Cry9C line were selected for enzyme-linked immunosorbent assay （ELISA） and insect bioassays. Expression of the Cry9C protein in the 35S：：Cry9C line maintained a high level in most tissues ranging from 24.6 to 45.5 ~tg g-I fresh weight. In green tissues such as the leaves, boll rinds, and bracts of the PNZIP：：Cry9C line, the Cry9C protein accumulated up to 50.2, 39.7, and 48.3 jag g-a fresh weight respectively. In contrast, seeds of the PNZIP：：Cry9C line （PZ1.3） accumulated only 0.26 ~ag g-~ fresh weight of the Cry9C protein, which was 100 times lower than that recorded for the seeds of the CaMV 35S：：Cry9C line. The insect bioassay showed that the transgenic PNZIP：：Cry9C cotton plant exhibited strong resistance to both the cotton bollworm and the pink bollworm. The PNZIP promoter could effectively drive Bt toxin ex- pression in green tissues of cotton and lower accumulated levels of the Bt protein in seeds. These features should allay public concerns about the safety of transgenic foods. We propose the future utility of PNZIP as an economical, environmentally friendly promoter in cotton biotechnology.展开更多
文摘Genetic engineering has created many genetically modified （GM） crop varieties that express the cry toxin from the bacterium Bacillus thuringiensis （Bt）. The cry toxin, synthesized during plant growth, has insecticidal properties, and can be expressed anywhere in the plant. This study aimed to ascertain the richness and species diversity of edaphic Formicidae and Coleoptera in GM cotton fields compared with the conventional non-transformed cotton crop. We analyzed data from commercial cotton fields located in the municipality of Maracaju, Mato Grosso do Sul, Brazil. The experiment was conducted during the reproductive period of cotton, employed two treatments： Bt cotton and non-Bt cotton. Samples were collected with pitfall traps. Formicidae species richness in the Bt area was lower than in the non-Bt area, but species composition did not differ between the two treatments. Species composition of Coleoptera communities also differed between the treatments because some species were more abundant in the Bt cotton area. On the other hand, the species richness of this group was similar in both areas.
基金the National Natural Science Foundation of China (31171592, 31371673)Fundamental Research Funds for the Central Universities (2013PY064)
文摘A promoter of the PNZIP （Pharbitis nil leucine zipper） gene （1.459 kb） was cloned from Pharbitis nil and fused to the GUS（^-glucuronidase） and Bacillus thuringiensis endotoxin （Cry9C） genes. Several transgenic PNZIP：：GUS and PNZIP：：Cry9C cotton lines were developed by Agrobacterium-mediated transformation. Strong GUS staining was detected in the green tissues of the transgenic PNZIP：：GUS cotton plants. In contrast, GUS staining in the reproductive structures such as petals, anther, and immature seeds of PNZIP：：GUS cotton was very faint. Two transgenic PNZIP：：Cry9C lines and one trans- genic cauliflower mosaic virus （CaMV） 35S：：Cry9C line were selected for enzyme-linked immunosorbent assay （ELISA） and insect bioassays. Expression of the Cry9C protein in the 35S：：Cry9C line maintained a high level in most tissues ranging from 24.6 to 45.5 ~tg g-I fresh weight. In green tissues such as the leaves, boll rinds, and bracts of the PNZIP：：Cry9C line, the Cry9C protein accumulated up to 50.2, 39.7, and 48.3 jag g-a fresh weight respectively. In contrast, seeds of the PNZIP：：Cry9C line （PZ1.3） accumulated only 0.26 ~ag g-~ fresh weight of the Cry9C protein, which was 100 times lower than that recorded for the seeds of the CaMV 35S：：Cry9C line. The insect bioassay showed that the transgenic PNZIP：：Cry9C cotton plant exhibited strong resistance to both the cotton bollworm and the pink bollworm. The PNZIP promoter could effectively drive Bt toxin ex- pression in green tissues of cotton and lower accumulated levels of the Bt protein in seeds. These features should allay public concerns about the safety of transgenic foods. We propose the future utility of PNZIP as an economical, environmentally friendly promoter in cotton biotechnology.
