A promoter of the PNZIP(Pharbitis nil leucine zipper)gene(1.459 kb)was cloned from Pharbitis nil and fused to the GUS(b-glucuronidase)and Bacillus thuringiensis endotoxin(Cry9C)genes.Several transgenic PNZIP::GUS and ...A promoter of the PNZIP(Pharbitis nil leucine zipper)gene(1.459 kb)was cloned from Pharbitis nil and fused to the GUS(b-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 transgenic cauliflower mosaic virus(Ca MV)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 from24.6 to 45.5μg g^(-1) 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 48.3μg g^(-1) fresh weight respectively.In contrast,seeds of the PNZIP::Cry9C line(PZ1.3)accumulated only 0.26μg g^(-1) fresh weight of the Cry9C protein,which was 100 times lower than that recorded for the seeds of the Ca MV 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 expression 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
Bacillus thuringiensis （Bt） cotton is grown worldwide, including in saline soils, but the effect of salinity on ion fluxes of Bt cotton remains unknown. Responses of two transgenic Bt cotton genotypes （SGK321 and 2...Bacillus thuringiensis （Bt） cotton is grown worldwide, including in saline soils, but the effect of salinity on ion fluxes of Bt cotton remains unknown. Responses of two transgenic Bt cotton genotypes （SGK321 and 29317） and their corresponding receptors, Shiyuan 321 （SY321） and Jihe 321 （J321）, to 150 mmol L-1 NaCl stress were studied in a growth chamber. The root dry weight of SGK321 and 29317 under NaCl treatment was decreased by 30 and 31%, respectively. However, their corresponding receptor cultivars SY321 and J321 were less affected （19 and 24%, respectively）. The root length and surface area of the Bt cultivars were significantly decreased relative to their receptors under salt stress. NaCl treatment significantly increased CrylAc mRNA transcript levels in SGK321 and 29317 but did not affect Bt protein content in leaves or roots of either cultivar at 1 and 7 d after NaCl treatment. Fluxes of Na^＋, K^＋, and H^＋ in roots were investigated using the scanning ion-selective electrode technique. Both mean K^＋ efflux rate and transient K^＋ efflux of the Bt cultivars increased four-fold compared to their corresponding receptors when exposed to salinity stress. There were no significant differences in Na^＋ efflux between Bt and non-Bt cottons. Furthermore, the Na^＋ contents in roots and leaves of all genotypes dramatically increased under salt stress, whereas K^＋ contents decreased. Our results suggested that Bt cotton cultivars are more sensitive to salt stress than their receptor genotypes.展开更多
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(b-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 transgenic cauliflower mosaic virus(Ca MV)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 from24.6 to 45.5μg g^(-1) 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 48.3μg g^(-1) fresh weight respectively.In contrast,seeds of the PNZIP::Cry9C line(PZ1.3)accumulated only 0.26μg g^(-1) fresh weight of the Cry9C protein,which was 100 times lower than that recorded for the seeds of the Ca MV 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 expression 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.
基金supported by the National Natural Science Foundation of China (30871490)the Specialized Research Fund for the Doctoral Program of Higher Education of Chinathe Innovation Fund for Graduate Students of China Agricultural University (KYCX2011007)
文摘Bacillus thuringiensis （Bt） cotton is grown worldwide, including in saline soils, but the effect of salinity on ion fluxes of Bt cotton remains unknown. Responses of two transgenic Bt cotton genotypes （SGK321 and 29317） and their corresponding receptors, Shiyuan 321 （SY321） and Jihe 321 （J321）, to 150 mmol L-1 NaCl stress were studied in a growth chamber. The root dry weight of SGK321 and 29317 under NaCl treatment was decreased by 30 and 31%, respectively. However, their corresponding receptor cultivars SY321 and J321 were less affected （19 and 24%, respectively）. The root length and surface area of the Bt cultivars were significantly decreased relative to their receptors under salt stress. NaCl treatment significantly increased CrylAc mRNA transcript levels in SGK321 and 29317 but did not affect Bt protein content in leaves or roots of either cultivar at 1 and 7 d after NaCl treatment. Fluxes of Na^＋, K^＋, and H^＋ in roots were investigated using the scanning ion-selective electrode technique. Both mean K^＋ efflux rate and transient K^＋ efflux of the Bt cultivars increased four-fold compared to their corresponding receptors when exposed to salinity stress. There were no significant differences in Na^＋ efflux between Bt and non-Bt cottons. Furthermore, the Na^＋ contents in roots and leaves of all genotypes dramatically increased under salt stress, whereas K^＋ contents decreased. Our results suggested that Bt cotton cultivars are more sensitive to salt stress than their receptor genotypes.
