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Sample records for bt transgenic plants

  1. The presence of Bt-transgenic oilseed rape in wild mustard populations affects plant growth.

    Science.gov (United States)

    Liu, Yongbo; Stewart, C Neal; Li, Junsheng; Huang, Hai; Zhang, Xitao

    2015-12-01

    The adventitious presence of transgenic plants in wild plant populations is of ecological and regulatory concern, but the consequences of adventitious presence are not well understood. Here, we introduced Bacillus thuringiensis Cry1Ac (Bt)-transgenic oilseed rape (Bt OSR, Brassica napus) with various frequencies into wild mustard (Brassica juncea) populations. We sought to better understand the adventitious presence of this transgenic insecticidal crop in a wild-relative plant population. We assessed the factors of competition, resource availability and diamondback moth (Plutella xylostella) infestation on plant population dynamics. As expected, Bt OSR performed better than wild mustard in mixed populations under herbivore attack in habitats with enough resources, whereas wild mustard had higher fitness when Bt OSR was rarer in habitats with limited resources. Results suggest that the presence of insect-resistant transgenic plants could decrease the growth of wild mustard and Bt OSR plants and their populations, especially under high herbivore pressure.

  2. [Effects of planting transgenic Bt + CpTI cotton on rhizosphere denitrifier abundance and diversity].

    Science.gov (United States)

    Dong, Lianhua; Meng, Ying; Wang, Jing

    2015-03-04

    To evaluate the effect of planting genetically modified cotton on soil denitrifer. The impact of transgenic Bt + CpTI cotton (SGK321) and its receptor cotton (SY321) on rhizosphere denitrifier abundance and diversity were investigated by using quantitative PCR (qPCR) and terminal restriction fragment length polymorphism (T-RFLP). We collected rhizosphere soil before cotton planting (Pre) and along with the cotton growth stage (budding, flowering, belling and boll opening). The abundance of denitrifier in both cottons changed significantly across the growth stage, but the variation tendency was different. In the rhizosphere of transgenic cotton, the denitrifier abundance increased from 3.12 x 10(6) copies/g dry soil (Pre) to 2.81 x 10(7) copies/g dry soil (belling). The denitrifier abundance in non-transgenic cotton was significantly affected by the growth stage: increased at budding, decreased at flowering, and then increased at belling. Canonical correspondence analysis and partial canonical correspondence analysis show that the denitrifier diversity was more correlated with pH, concentration of NO3- and budding and flowering. Additionally, cotton genotype was an important factor of influencing the diversity of denitrifier. This indicates the abundance and diversity were influenced by both the cotton growth stage and the cotton genotype by adjusting the soil pH and concentration of NO3-. Planting of transgenic Bt + CpTI cotton leads an increase in the soil pH, which results in an increase in abundance and diversity of denitrifier.

  3. Hybridizing transgenic Bt cotton with non-Bt cotton counters resistance in pink bollworm

    National Research Council Canada - National Science Library

    Wan, Peng; Xu, Dong; Cong, Shengbo; Jiang, Yuying; Huang, Yunxin; Wang, Jintao; Wu, Huaiheng; Wang, Ling; Wu, Kongming; Carriere, Yves; Mathias, Andrea; Li, Xianchun; Tabashnik, Bruce E

    2017-01-01

    .... However, these benefits are being eroded by evolution of resistance in pests. We report a strategy for combating resistance by crossing transgenic Bt plants with conventional non-Bt plants and then crossing the resulting first-generation (F1...

  4. Segregation and expression of transgenes in the progenies of Bt ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-04-17

    Apr 17, 2012 ... rent progenies of Bt transgenic rice crosses to conventional rice varieties was analyzed by Western dot blotting. The samples derived from GUS positive plants of. Bt transgenic rice crossed to conventional rice varieties were found to produce a higher level of toxin protein, but with greater range of variation.

  5. Biosafety assessment of transgenic Bt cotton on model animals

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    Sadia Bano

    2016-05-01

    Full Text Available Abstract Background: To know the effects of transgenic crops on soil microorganisms, animals and other expected hazards due to the introduction of GM crops into the environment is critical both scientifically and environmentally. The work was conducted to study the effect of insecticidal Bt protein on Rats and Earthworms. Methods: For this purpose, animals like rat and soil organisms like Earthworm were selected. Rats were selected on the basis of its 95% homology on genomic, cellular and enzymatic level with human while earthworm were preferred on the basis of their direct contact with soil to evaluate the impact of Bt (Cry1AC crop field soil on earthworm, secreted by root exudates of Bt cotton. Several physical, molecular, biochemical and histological analyses were performed on both Rats/Earthworms fed on standard diet (control group as well containing Bt protein (experimental group. Results: Molecular analyses such as immune Dot blot, SDS-PAGE, ELISA and PCR, confirmed the absence of Cry1Ac protein in blood and urine samples of rats, which were fed with Bt protein in their diet. Furthermore, histological studies showed that there was no difference in cellular architecture in liver, heart, kidney and intestine of Bt and non-Bt diet fed rats. To see the effect of Bt on earthworm two different groups were studied, one with transgenic plant field soil supplemented with grinded leaves of cotton and second group with non-Bt field soil. Conclusions: No lethal effects of transgenic Bt protein on the survival of earthworm and rats were observed. Bradford assay, Dipstick assay ELISA demonstrated the absence of Cry1Ac protein in the mid-gut epithelial tissue of earthworm. The results of present study will be helpful in successful deployment and commercial release of genetically modified crop in Pakistan.

  6. Cannibalism of Helicoverpa zea (Lepidoptera: Noctuidae) from Bacillus thuringiensis (Bt) transgenic corn versus non-Bt corn.

    Science.gov (United States)

    Chilcutt, Charles F

    2006-06-01

    Because of the importance of cannibalism in population regulation of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in corn, Zea mays L., it is useful to understand the interactions between Bacillus thuringiensis (Bt) transgenic corn and cannibalism. To determine the effects of Bt corn on cannibalism in H. zea, pairs of the same or different instars were taken from Bt or non-Bt corn and placed on artificial diet in proximity. Cannibalism occurred in 91% of pairs and was approximately 7% greater for pairs of larvae reared from Bt transgenic corn (95%) than from non-Bt corn (88%). Also, first instar by first instar pairs had a lower rate of cannibalism than other pairs. Time until cannibalism was not different for larvae from Bt corn versus non-Bt corn. Pupation rate of cannibals and surviving victims was not different for pairs from Bt corn versus non-Bt corn. Finally, cannibalism increased pupation rate of cannibals from both Bt and non-Bt corn by approximately 23 and 12%, respectively, although the increases were not significant. Thus, negative effects of Bt on larvae were compensated by increased cannibalism in comparison with larvae reared on non-Bt corn, which increased larval survival to levels comparable with larvae reared on non-Bt plants.

  7. Fitness of Bt-resistant cabbage loopers on Bt cotton plants.

    Science.gov (United States)

    Tetreau, Guillaume; Wang, Ran; Wang, Ping

    2017-10-01

    Development of resistance to the insecticidal toxins from Bacillus thuringiensis (Bt) in insects is the major threat to the continued success of transgenic Bt crops in agriculture. The fitness of Bt-resistant insects on Bt and non-Bt plants is a key parameter that determines the development of Bt resistance in insect populations. In this study, a comprehensive analysis of the fitness of Bt-resistant Trichoplusia ni strains on Bt cotton leaves was conducted. The Bt-resistant T. ni strains carried two genetically independent mechanisms of resistance to Bt toxins Cry1Ac and Cry2Ab. The effects of the two resistance mechanisms, individually and in combination, on the fitness of the T. ni strains on conventional non-Bt cotton and on transgenic Bt cotton leaves expressing a single-toxin Cry1Ac (Bollgard I) or two Bt toxins Cry1Ac and Cry2Ab (Bollgard II) were examined. The presence of Bt toxins in plants reduced the fitness of resistant insects, indicated by decreased net reproductive rate (R0 ) and intrinsic rate of increase (r). The reduction in fitness in resistant T. ni on Bollgard II leaves was greater than that on Bollgard I leaves. A 12.4-day asynchrony of adult emergence between the susceptible T. ni grown on non-Bt cotton leaves and the dual-toxin-resistant T. ni on Bollgard II leaves was observed. Therefore, multitoxin Bt plants not only reduce the probability for T. ni to develop resistance but also strongly reduce the fitness of resistant insects feeding on the plants. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Effects of Bt-transgenic rice cultivation on planktonic communities in paddy fields and adjacent ditches

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yongbo, E-mail: liuyb@craes.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Liu, Fang [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Wang, Chao [Pearl River Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou 510380 (China); Quan, Zhanjun [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Junsheng, E-mail: lijsh@creas.org.cn [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China)

    2016-09-15

    The non-target effects of transgenic plants are issues of concern; however, their impacts in cultivated agricultural fields and adjacent natural aquatic ecosystems are poorly understood. We conducted field experiments during two growing seasons to determine the effects of cultivating Bacillus thuringiensis (Bt)-transgenic rice on the phytoplankton and zooplankton communities in a paddy field and an adjacent ditch. Bt toxin was detected in soil but not in water. Water quality was not significantly different between non-Bt and Bt rice fields, but varied among up-, mid- and downstream locations in the ditch. Cultivation of Bt-transgenic rice had no effects on zooplankton communities. Phytoplankton abundance and biodiversity were not significantly different between transgenic and non-transgenic rice fields in 2013; however, phytoplankton were more abundant in the transgenic rice field than in the non-transgenic rice field in 2014. Water quality and rice type explained 65.9% and 12.8% of this difference in 2014, respectively. Phytoplankton and zooplankton were more abundant in mid- and downstream, than upstream, locations in the ditch, an effect that we attribute to water quality differences. Thus, the release of Bt toxins into field water during the cultivation of transgenic crops had no direct negative effects on plankton community composition, but indirect effects that alter environmental conditions should be taken into account during the processes of management planning and policymaking. - Highlights: • We detect fusion Cry1Ab/1Ac proteins from Bt rice entering into aquatic ecosystems. • Bt-transgenic rice cultivation have no significant effect on zooplankton community. • Bt-transgenic rice cultivation have indirect effect on phytoplankton community. • Water quality explains the difference of plankton communities in adjacent ditches.

  9. Early warning of cotton bollworm resistance associated with intensive planting of Bt cotton in China

    National Research Council Canada - National Science Library

    Zhang, Haonan; Yin, Wei; Zhao, Jing; Jin, Lin; Yang, Yihua; Wu, Shuwen; Tabashnik, Bruce E; Wu, Yidong

    2011-01-01

    .... To delay pest resistance to transgenic cotton producing Bt toxin Cry1Ac, farmers in the United States and Australia planted refuges of non-Bt cotton, while farmers in China have relied on "natural...

  10. Interaction Between Bt-Transgenic Cotton and the Whitefly’s Parasitoid, Encarsia Formosa (Hymenoptera: Aphelinidae

    Directory of Open Access Journals (Sweden)

    Azimi Solmaz

    2014-07-01

    Full Text Available Transgenic Bt cotton developed against lepidopteran pests may not be compatible with parasitoid of secondary pests such as Bemisia tabaci which attack many plants such as cotton. In this study, the effects of Bt cotton on the demographic parameters of Encarsia formosa, parasitoid of B. tabaci were assessed. The data were analysed using the age specific, two-sex life table parameters. The results indicated that pre-adult developmental time, the total preoviposition period (TPOP and the adult preoviposition period (APOP in the Bt cotton were significantly longer than in the non-Bt cotton. Also, fecundity and body size in both lines were significantly different. The fecundity was 23.64±0.73 and 43.75±0.89 eggs/females in the Bt and non-Bt cotton, respectively. All the population parameters were affected by the Bt cotton. The intrinsic rate of increase (r was 0.15 day-1 in the non-Bt cotton but it was 0.10 day-1 in the Bt cotton. The finite rate of increase (λ was 1.11 day-1 in the non-Bt cotton whilst it was 1.08 in the Bt cotton. The net reproductive rate (R0 in the non-Bt cotton was 36.75 but in the Bt cotton these parameters showed 19.62 offspring/individual. Also, the mean generation time (T in the non-Bt and Bt cotton was 22.69 and 27.79 days, respectively. The results illustrated, that although transgenic crops are effective tools for management of the target pests, they can adversely affect, either directly or indirectly, the natural enemies dependent on these plants.

  11. Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton.

    Directory of Open Access Journals (Sweden)

    Jun-Yu Luo

    Full Text Available An increasing area of transgenic Bacillus thuringiensis (Bt cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW Helicoverpa armigera (Hübner in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]. We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels.

  12. Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton.

    Science.gov (United States)

    Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie

    2017-01-01

    An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels.

  13. Effects of transgenic Bt+CpTI cotton on the growth and reproduction of earthworm Eisenia foetida.

    Science.gov (United States)

    Liu, Biao; Cui, Jinjie; Meng, Jun; Hu, Wenjun; Luo, Junyu; Zheng, Yangping

    2009-01-01

    With the expansion of the planted area of transgenic Bt+CpTI cotton, the effects of this crop on non-target organisms in soil, including earthworms, are becoming the most important aspect of their ecological risk assessment. Laboratory toxicity studies were conducted to determine the effects of transgenic Bt+CpTI cotton leaves, containing high concentrations of the Bt toxin and cowpea trypsin inhibitor, on the earthworm Eisenia foetida. In comparison with the non-transgenic cotton line Zhong23, transgenic Bt+CpTI cotton Zhong41 had no significant acute toxicity on E. foetida. Moreover, the leaves of transgenic Bt+CpTI cotton were more suitable than the non-transgenic cotton Zhong23 for E. foetida growth and reproduction (time of reproduction, the number of cocoons and newly incubated offspring).

  14. Elevated atmospheric ozone increases concentration of insecticidal Bacillus thuringiensis (Bt) Cry1Ac protein in Bt Brassica napus and reduces feeding of a Bt target herbivore on the non-transgenic parent

    Energy Technology Data Exchange (ETDEWEB)

    Himanen, Sari J. [University of Kuopio, Department of Environmental Science, P.O. Box 1627, FIN-70211 Kuopio (Finland)], E-mail: sari.himanen@uku.fi; Nerg, Anne-Marja [University of Kuopio, Department of Environmental Science, P.O. Box 1627, FIN-70211 Kuopio (Finland); Nissinen, Anne [University of Kuopio, Department of Environmental Science, P.O. Box 1627, FIN-70211 Kuopio (Finland); MTT Agrifood Research Finland, Plant Protection, FIN-31600 Jokioinen (Finland); Stewart, C. Neal [University of Tennessee, Department of Plant Sciences, Knoxville, TN 37996-4561 (United States); Poppy, Guy M. [University of Southampton, School of Biological Sciences, Southampton SO16 7PX (United Kingdom); Holopainen, Jarmo K. [University of Kuopio, Department of Environmental Science, P.O. Box 1627, FIN-70211 Kuopio (Finland)

    2009-01-15

    Sustained cultivation of Bacillus thuringiensis (Bt) transgenic crops requires stable transgene expression under variable abiotic conditions. We studied the interactions of Bt toxin production and chronic ozone exposure in Bt cry1Ac-transgenic oilseed rape and found that the insect resistance trait is robust under ozone elevations. Bt Cry1Ac concentrations were higher in the leaves of Bt oilseed rape grown under elevated ozone compared to control treatment, measured either per leaf fresh weight or per total soluble protein of leaves. The mean relative growth rate of a Bt target herbivore, Plutella xylostella L. larvae was negative on Bt plants in all ozone treatments. On the non-transgenic plants, larval feeding damage was reduced under elevated ozone. Our results indicate the need for monitoring fluctuations in Bt toxin concentrations to reveal the potential of ozone exposure for altering dosing of Bt proteins to target and non-target herbivores in field environments experiencing increasing ozone pollution. - Elevated atmospheric ozone can induce fluctuations in insecticidal protein concentrations in transgenic plants.

  15. The effects of Fe2O3 nanoparticles on physiology and insecticide activity in non-transgenic and Bt-transgenic cotton

    Directory of Open Access Journals (Sweden)

    Nhan eLe Van

    2016-01-01

    Full Text Available As the demands for nanotechnology and nanoparticle (NP applications in agriculture increase, the ecological risk has drawn more attention because of the unpredictable results of interactions between NPs and transgenic crops. In this study, we investigated the effects of various concentrations of Fe2O3 NPs on Bt-transgenic cotton in comparison with conventional cotton for 10 days. Each treatment was conducted in triplicate, and each experiment was repeated three times. Results demonstrated that Fe2O3 nanoparticles (NPs inhibited the plant height and root length of Bt-transgenic cotton and promoted root hairs and biomass of non-transgenic cotton. Nutrients such as Na and K in Bt-transgenic cotton roots increased, while Zn contents decreased with Fe2O3 NPs. Most hormones in the roots of Bt-transgenic cotton increased at low Fe2O3 NP exposure (100 mg·L−1 but decreased at high concentrations of Fe2O3 NPs (1000 mg·L−1. Fe2O3 NPs increased the Bt-toxin in leaves and roots of Bt-transgenic cotton. Fe2O3 NPs were absorbed into roots, then transported to the shoots of both Bt-transgenic and non-transgenic cottons. The bioaccumulation of Fe2O3 NPs in plants might be a potential risk for agricultural crops and affect the environment and human health.

  16. Food safety knowledge on the Bt mutant protein Cry8Ka5 employed in the development of coleopteran-resistant transgenic cotton plants.

    Science.gov (United States)

    Farias, Davi F; Peijnenburg, Ad A C M; Grossi-de-Sá, Maria F; Carvalho, Ana F U

    2015-01-01

    Insecticidal Cry proteins from Bacillus thuringiensis (Bt) have been exploited in the development of genetically modified (GM) crops for pest control. However, several pests are still difficult to control such as the coleopteran boll weevil Anthonomus grandis. By applying in vitro molecular evolution to the cry8Ka1 gene sequence, variants were generated with improved activity against A. grandis. Among them, Cry8Ka5 mutant protein showed coleoptericidal activity 3-fold higher (LC50 2.83 μg/mL) than that of the original protein (Cry8Ka1). Cry8Ka5 has been used in breeding programs in order to obtain coleopteran-resistant cotton plants. Nevertheless, there is some concern in relation to the food safety of transgenic crops, especially to the heterologously expressed proteins. In this context, our research group has performed risk assessment studies on Cry8Ka5, using the tests recommended by Codex as well as tests that we proposed as alternative and/or complementary approaches. Our results on the risk analysis of Cry8Ka5 taken together with those of other Cry proteins, point out that there is a high degree of certainty on their food safety. It is reasonable to emphasize that most safety studies on Cry proteins have essentially used the Codex approach. However, other methodologies would potentially provide additional information such as studies on the effects of Cry proteins and derived peptides on the indigenous gastrointestinal microbiota and on intestinal epithelial cells of humans. Additionally, emerging technologies such as toxicogenomics potentially will offer sensitive alternatives for some current approaches or methods.

  17. Comparative studies on the effects of Bt-transgenic and nontransgenic cotton on arthropod diversity, seedcotton yield and bollworms control.

    Science.gov (United States)

    Dhillon, M K; Sharma, H C

    2013-01-01

    The effectiveness of commercial Bt-cotton in pest management, influence on arthropod diversity, natural enemies, and toxin flow in the insect fauna under field conditions were studied keeping in view the need to assess bioefficacy and biosafety of Bt-transgenic cotton. There were no significant differences in oviposition by Helicoverpa armigera on Bt-transgenic and non-transgenic cottons (9.2 versus 9.6 eggs plants(-100)), while the numbers of H. armigera larvae were significantly more on non-transgenic than on Bt-transgenic (10.4 versus 4.0 larvae plants(-100)) cotton. The Bt-cotton had significantly more number of mature opened bolls (9.6 versus 4.4 bolls plant(-1)), lower bollworm damage (12.8 versus 40.2% bolls damaged), and higher seedcotton yield (667.7 versus 231.7 kg ha 1). Population of cotton leafhopper, Amrasca biguttula biguttula was lower (582.2 versus 732.2 leafhoppers plants(-100)), while that of whitefly, Bemisia tabaci was higher on Bt-transgenic (65.2 versus 45.6 whiteflies plants(-100)) than on non-transgenic cotton. There was no significant influence of Bt-transgenic cotton on abundance of natural enemies of crop pests - chrysopids (9.6 versus 8.4 chrysopids plants(-100), ladybird beetles (16.0 versus 10.8 ladybirds plants(-100)), and spiders (128.4 versus 142.8 spiders plants(-100)). There were no significant differences in H. ormigera egg (19.8 versus 20.9%), larval (7.4 versus 9.6%), and larval-pupal (1.3 versus 2.9%) parasitism on Bt-transgenic and non-transgenic cottons in the farmer's fields. The parasitism in larvae of H. armigera was far lower than that of the eggs, which might be because of early mortality of H. armigera prior to parasitoid development in the host larvae. Although, Cry1Ac Bt toxin was detected in Cheilomenes sexmoculatus, chrysopids, A. bigutulla bigutulla, Thrips taboci, Myllocerus sp., Oxycarenus laetus, Dysdercus koenigii, spiders, bugs, and grasshoppers, no significant differences were observed in their abundance on

  18. Bacillus thuringiensis (Bt) transgenic crop: an environment friendly insect-pest management strategy.

    Science.gov (United States)

    Kumar, Suresh; Chandra, Amaresh; Pandey, K C

    2008-09-01

    Introduction of DDT (dichloro-diphenyl-trichloroethane) and following move towards indiscriminate use of synthetic chemical insecticides led to the contamination of water and food sources, poisoning of non-target beneficial insects and development of insect-pests resistant to the chemical insecticides. Increased public concems about the adverse environmental effects of indiscriminate use of chemical insecticides prompted search of altemative methods for insect-pest control. One of the promising alternatives has been the use of biological control agents. There is well-documented history of safe application of Bt (B. thuringiensis, a gram positive soil bacterium) as effective biopesticides and a number of reports of expression of delta-endotoxin gene(s) in crop plants are available. Only a few insecticidal sprays are required on Bt transgenic crops, which not only save cost and time, but also reduce health risks. Insects exhibit remarkable ability to develop resistance to different insecticidal compounds, which raises concern about the unsystematic use of Bt transgenic technology also. Though resistance to Bt products among insect species under field conditions has been rare, laboratory studies show that insects are capable of developing high levels of resistance to one ormore Cry proteins. Now it is generally agreed that 'high-dose/refuge strategy' is the most promising and practical approach to prolong the effectiveness of Bt toxins. Although manybiosafety concerns, ethical and moral issues exist, area under Bt transgenic crops is rapidly increasing and they are cultivated on more than 32 million hectares world over Even after reservation of European Union (EU) for acceptance of geneticaly modified (GM) crops, 6 out of 25 countries have already adopted Bt crops and many otherindustrial countries will adopt Bt transgenic crops in near future. While the modem biotechnology has been recognized to have a great potential for the promotion of human well-being, adoption

  19. Generation of marker-free Bt transgenic indica rice and evaluation of its yellow stem borer resistance.

    Science.gov (United States)

    Kumar, S; Arul, L; Talwar, D

    2010-01-01

    We report on generation of marker-free (‘clean DNA’) transgenic rice (Oryza sativa), carrying minimal gene-expression-cassettes of the genes of interest, and evaluation of its resistance to yellow stem borer Scirpophaga incertulas (Lepidoptera: Pyralidae). The transgenic indica rice harbours a translational fusion of 2 different Bacillus thuringiensis (Bt) genes, namely cry1B-1Aa, driven by the green-tissue-specific phosphoenol pyruvate carboxylase (PEPC) promoter. Mature seed-derived calli of an elite indica rice cultivar Pusa Basmati-1 were co-bombarded with gene-expression-cassettes (clean DNA fragments) of the Bt gene and the marker hpt gene, to generate marker-free transgenic rice plants. The clean DNA fragments for bombardment were obtained by restriction digestion and gel extraction. Through biolistic transformation, 67 independent transformants were generated. Transformation frequency reached 3.3%, and 81% of the transgenic plants were co-transformants. Stable integration of the Bt gene was confirmed, and the insert copy number was determined by Southern analysis. Western analysis and ELISA revealed a high level of Bt protein expression in transgenic plants. Progeny analysis confirmed stable inheritance of the Bt gene according to the Mendelian (3:1) ratio. Insect bioassays revealed complete protection of transgenic plants from yellow stem borer infestation. PCR analysis of T2 progeny plants resulted in the recovery of up to 4% marker-free transgenic rice plants.

  20. Regulation of the seasonal population patterns of Helicoverpa armigera moths by Bt cotton planting.

    Science.gov (United States)

    Gao, Yu-Lin; Feng, Hong-Qiang; Wu, Kong-Ming

    2010-08-01

    Transgenic cotton expressing the Bacillus thuringiensis (Bt) Cry1Ac toxin has been commercially cultivated in China since 1997, and by 2000 Bt cotton had almost completely replaced non-transgenic cotton cultivars. To evaluate the impact of Bt cotton planting on the seasonal population patterns of cotton bollworm, Helicoverpa armigera, the dynamics of H. armigera moths were monitored with light traps from four locations (Xiajin, Linqing and Dingtao of Shandong Province; Guantao of Hebei Province) in high Bt density region and five locations (Anci and Xinji of Hebei Province; Dancheng and Fengqiu of Henan Province; Gaomi of Shandong Province) in low Bt density region from 1996 to 2008. A negative correlation was found between moth densities of H. armigera and the planting years of Bt cotton in both high and low Bt density areas. These data indicate that the moth population density of H. armigera was reduced with the introduction of Bt cotton in northern China. Three generations of moths occurred between early June and late September in the cotton regions. Interestingly, second-generation moths decreased and seemed to vanish in recent years in high Bt density region, but this tendency was not found in low Bt density region. The data suggest that the planting of Bt cotton in high Bt density region was effective in controlling the population density of second-generation moths. Furthermore, the seasonal change of moth patterns associated with Bt cotton planting may regulate the regional occurrence and population development of this migratory insect.

  1. Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize.

    Science.gov (United States)

    Burkness, Eric C; Cira, T M; Moser, S E; Hutchison, W D

    2015-12-01

    In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. An Empirical Assessment of Transgene Flow from a Bt Transgenic Poplar Plantation.

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    Jianjun Hu

    Full Text Available To assess the possible impact of transgenic poplar plantations on the ecosystem, we analyzed the frequency and distance of gene flow from a mature male transgenic Populus nigra plantation carrying the Bacillus thuringiensis toxin gene (Bt poplar and the survival of Bt poplar seeds. The resultant Bt poplar seeds occurred at a frequency of ~0.15% at 0 m to ~0.02% at 500 m from the Bt poplar plantation. The germination of Bt poplar seeds diminished within three weeks in the field (germination rate from 68% to 0% compared to 48% after three weeks of storage at 4°C. The survival rate of seedlings in the field was 0% without any treatment but increased to 1.7% under the addition of four treatments (cleaning and trimming, watering, weeding, and covering with plastic film to maintain moisture after being seeded in the field for eight weeks. The results of this study indicate that gene flow originating from the Bt poplar plantation occurred at an extremely low level through pollen or seeds under natural conditions. This study provides first-hand field data on the extent of transgene flow in poplar plantations and offers guidance for the risk assessment of transgenic poplar plantations.

  3. [Arthropod community structures in transgenic Bt cotton fields].

    Science.gov (United States)

    Wei, G; Cui, L; Zhang, X; Liu, S; Lü, N; Zhang, Q

    2001-08-01

    Arthropod community structures were investigated in transgenic Bt cultivars, Bollgard(B) and Chinese cotton 30 (CC30), and common cultivars, control (C) and no control (NC) cotton field in North China in 1998. The results showed that compared with common cultivars, the species richness and the number of total individual of arthropod community in transgenic Bt cultivars field were reduced 2.4-16.3% and 71.0-78.3% respectively, in which dominant species in phytophagous subcommunity varied. The number of individual of predatory and parastic subcommunity were all increased. The similarity coefficient between CC30 and NC was 0.8243, B and NC 0.7320, B and C 0.3380, C and NC 0.3128, CC30 and C 0.2665. The order of diversity and evenness value of these were CC30 (2.3712 and 0.6428), NC (2.3654 and 0.6251), B (2.1364 and 0.5791), and C (1.0877 and 0.2949), their dominant value was 0.8726 (C), 0.3528(B), 0.1178(NC) and 0.1048 (CC30) respectively. It was concluded that different integrated pest management (IPM) strategy should be implemented in transgenic Bt cotton instead of common variety cotton field.

  4. Life history traits of Helicoverpa zea (Lepidoptera: Noctuidae) on non-Bt and Bt transgenic corn hybrids in eastern North Carolina.

    Science.gov (United States)

    Storer, N P; Van Duyn, J W; Kennedy, G G

    2001-10-01

    Transgenic varieties of field corn that express the CrylAb B. thuringiensis (Bt) toxin in ear tissue present the potential of reducing ear feeding by the corn earworm, Helicoverpa zea (Lepidoptera: Noctuidae), and for reducing the size of populations of the insect infesting other host crops. Life history parameters of H. zea feeding on ears of conventional and Bt field corn varieties were measured in field plots in eastern North Carolina in 1997 and 1998. Transformation events investigated were Mon-810 and Bt-11. Bt corn was found to cause a steady mortality of larvae during development, but permitted approximately 15-40% survival to the prepupal stage compared with non-Bt corn. Mortality of prepupae and pupae from Bt corn was also higher than from non-Bt corn, reducing overall adult production by 65-95%. The larvae that did survive grew more slowly on Bt than on non-Bt corn, and produced pupae that weighed 33% less. Pupation and adult eclosion were delayed by 6-10 d by feeding on Bt corn ears. Corn varieties expressing Bt in ear tissue have the potential to reduce H. zea ear feeding by up to 80%, and the potential to reduce populations emerging from ear-stage corn fields to infest cotton, soybean and other crops by around 75%. To have a measurable effect on area-wide populations, Bt corn varieties would need to be planted in large proportions of corn fields. Extensive planting of varieties such as those tested here, having only moderate effects on H. zea, would raise concerns about rapid evolution of resistance.

  5. transgenic plants

    African Journals Online (AJOL)

    been initiated in this area by the Global Pest. Resistance Management Programme located at. MSU. Through effective resistance management training, pesticide use patterns change, and the effective lift: span of pesticides and host plant resistance technology increases. Effective resistance management can mean reduced.

  6. Target and nontarget effects of novel "triple-stacked" Bt-transgenic cotton 1: canopy arthropod communities.

    Science.gov (United States)

    Whitehouse, M E A; Wilson, L J; Davies, A P; Cross, D; Goldsmith, P; Thompson, A; Harden, S; Baker, G

    2014-02-01

    Transgenic cotton varieties (Bollgard II) expressing two proteins (Cry1Ac and Cry2Ab) from Bacillus thuringiensis (Bt) have been widely adopted in Australia to control larvae of Helicoverpa. A triple-stacked Bt-transgenic cotton producing Cry1Ac, Cry2Ab, and Vip3A proteins (Genuity Bollgard III) is being developed to reduce the chance that Helicoverpa will develop resistance to the Bt proteins. Before its introduction, nontarget effects on the agro-ecosystem need to be evaluated under field conditions. By using beatsheet and suction sampling methods, we compared the invertebrate communities of unsprayed non-Bt-cotton, Bollgard II, and Bollgard III in five experiments across three sites in Australia. We found significant differences between invertebrate communities of non-Bt and Bt (Bollgard II and Bollgard III) cotton only in experiments where lepidopteran larval abundance was high. In beatsheet samples where lepidopterans were absent (Bt crops), organisms associated with flowers and bolls in Bt-cotton were more abundant. In suction samples, where Lepidoptera were present (i.e., in non-Bt-cotton), organisms associated with damaged plant tissue and frass were more common. Hence in our study, Bt- and non-Bt-cotton communities only differed when sufficient lepidopteran larvae were present to exert both direct and indirect effects on species assemblages. There was no overall significant difference between Bollgard II and III communities, despite the addition of the Vip gene in Bollgard III. Consequently, the use of Bollgard III in Australian cotton provides additional protection against the development of resistance by Helicoverpa to Bt toxins, while having no additional effect on cotton invertebrate communities.

  7. Early warning of cotton bollworm resistance associated with intensive planting of Bt cotton in China.

    Directory of Open Access Journals (Sweden)

    Haonan Zhang

    Full Text Available Transgenic crops producing Bacillus thuringiensis (Bt toxins kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to promote survival of susceptible pests. To delay pest resistance to transgenic cotton producing Bt toxin Cry1Ac, farmers in the United States and Australia planted refuges of non-Bt cotton, while farmers in China have relied on "natural" refuges of non-Bt host plants other than cotton. Here we report data from a 2010 survey showing field-evolved resistance to Cry1Ac of the major target pest, cotton bollworm (Helicoverpa armigera, in northern China. Laboratory bioassay results show that susceptibility to Cry1Ac was significantly lower in 13 field populations from northern China, where Bt cotton has been planted intensively, than in two populations from sites in northwestern China where exposure to Bt cotton has been limited. Susceptibility to Bt toxin Cry2Ab did not differ between northern and northwestern China, demonstrating that resistance to Cry1Ac did not cause cross-resistance to Cry2Ab, and implying that resistance to Cry1Ac in northern China is a specific adaptation caused by exposure to this toxin in Bt cotton. Despite the resistance detected in laboratory bioassays, control failures of Bt cotton have not been reported in China. This early warning may spur proactive countermeasures, including a switch to transgenic cotton producing two or more toxins distinct from Cry1A toxins.

  8. A comparison of Bt transgene, hybrid background, water stress, and insect stress effects on corn leaf and ear injury and subsequent yield.

    Science.gov (United States)

    Brewer, Michael J; Odvody, Gary N; Anderson, Darwin J; Remmers, Jeffrey C

    2014-06-01

    Experimentally manipulated water and insect stresses were applied to field-grown corn with different Bacillus thuringiensis (Bt) transgenes and no Bt transgenes, and different nontransgenic hybrid backgrounds (2011 and 2012, Corpus Christi, TX). Differences in leaf injury, ear injury, and yield were detected among experimental factors and their interactions. Under high and low water stress, injury from noctuid larvae (Lepidoptera: Noctuidae) on leaves during vegetative growth (primarily from fall armyworm, Spodoptera frugiperda J.E. Smith) and on developing ears (primarily from corn earworm, Helicoverpa zea [Boddie]) was lowest on more recent releases of Bt hybrids (newer Bt hybrids) expressing Cry1A.105+Cry2Ab2 and Cry 3Bb1, compared with earlier Bt hybrids (older Bt hybrids) expressing Cry1Ab and Cry3Bb1 and non-Bt hybrids. High water stress led to increased leaf injury under substantial fall armyworm feeding pressure in 2011 (as high as 8.7 on a 1-9 scale of increasing injury). In contrast, ear injury by corn earworm (as high as 20 cm(2) of surface area of injury) was greater in low water stress conditions. Six hybrid backgrounds did not influence leaf injury, while ear injury differences across hybrid backgrounds were detected for non-Bt and older Bt hybrid versions. While newer Bt hybrids expressing Cry1A.105+Cry2Ab2 and Cry 3Bb1 had consistent low leaf injury and high yield and low but less consistent ear injury across six hybrid backgrounds, water stress was a key factor that influenced yield. Bt transgenes played a more variable and lesser role when interacting with water stress to affect yield. These results exemplify the interplay of water and insect stress with plant injury and yield, their interactions with Bt transgenes, and the importance of these interactions in considering strategies for Bt transgene use where water stress is common.

  9. Molecular Analyses of Transgenic Plants.

    Science.gov (United States)

    Trijatmiko, Kurniawan Rudi; Arines, Felichi Mae; Oliva, Norman; Slamet-Loedin, Inez Hortense; Kohli, Ajay

    2016-01-01

    One of the major challenges in plant molecular biology is to generate transgenic plants that express transgenes stably over generations. Here, we describe some routine methods to study transgene locus structure and to analyze transgene expression in plants: Southern hybridization using DIG chemiluminescent technology for characterization of transgenic locus, SYBR Green-based real-time RT-PCR to measure transgene transcript level, and protein immunoblot analysis to evaluate accumulation and stability of transgenic protein product in the target tissue.

  10. Food safety knowledge on the Bt mutant protein Cry8Ka5 employed in the development of coleopteran-resistant transgenic cotton plants

    NARCIS (Netherlands)

    Felipe Farias, Davi; Peijnenburg, A.A.C.M.; Grossi-de-Sá, Maria F.; Carvalho, A.F.U.

    2015-01-01

    Insecticidal Cry proteins from Bacillus thuringiensis (Bt) have been exploited in the development of genetically modified (GM) crops for pest control. However, several pests are still difficult to control such as the coleopteran boll weevil Anthonomus grandis. By applying in vitro molecular

  11. Limited fitness advantages of crop-weed hybrid progeny containing insect-resistant transgenes (Bt/CpTI in transgenic rice field.

    Directory of Open Access Journals (Sweden)

    Xiao Yang

    Full Text Available BACKGROUND: The spread of insect-resistance transgenes from genetically engineered (GE rice to its coexisting weedy rice (O. sativa f. spontanea populations via gene flow creates a major concern for commercial GE rice cultivation. Transgene flow to weedy rice seems unavoidable. Therefore, characterization of potential fitness effect brought by the transgenes is essential to assess environmental consequences caused by crop-weed transgene flow. METHODOLOGY/PRINCIPAL FINDINGS: Field performance of fitness-related traits was assessed in advanced hybrid progeny of F(4 generation derived from a cross between an insect-resistant transgenic (Bt/CpTI rice line and a weedy strain. The performance of transgene-positive hybrid progeny was compared with the transgene-negative progeny and weedy parent in pure and mixed planting of transgenic and nontransgenic plants under environmental conditions with natural vs. low insect pressure. Results showed that under natural insect pressure the insect-resistant transgenes could effectively suppress target insects and bring significantly increased fitness to transgenic plants in pure planting, compared with nontransgenic plants (including weedy parent. In contrast, no significant differences in fitness were detected under low insect pressure. However, such increase in fitness was not detected in the mixed planting of transgenic and nontransgenic plants due to significantly reduced insect pressure. CONCLUSIONS/SIGNIFICANCE: Insect-resistance transgenes may have limited fitness advantages to hybrid progeny resulted from crop-weed transgene flow owning to the significantly reduced ambient target insect pressure when an insect-resistant GE crop is grown. Given that the extensive cultivation of an insect-resistant GE crop will ultimately reduce the target insect pressure, the rapid spread of insect-resistance transgenes in weedy populations in commercial GE crop fields may be not likely to happen.

  12. Exposure and nontarget effects of transgenic Bt corn debris in streams.

    Science.gov (United States)

    Jensen, Peter D; Dively, Galen P; Swan, Christopher M; Lamp, William O

    2010-04-01

    Corn (Zea mays L.) transformed with a gene from the bacterium Bacillus thuringiensis (Bt) comprises 49% of all corn in the United States. The input of senesced corn tissue expressing the Bt gene may impact stream-inhabiting invertebrates that process plant debris, especially trichopteran species related to the target group of lepidopteran pests. Our goal was to assess risk associated with transgenic corn debris entering streams. First, we show the input of corn tissue after harvest was extended over months in a stream. Second, using laboratory bioassays based on European corn borer [Ostrinia nubilalis (Hübner)], we found no bioactivity of Cry1Ab protein in senesced corn tissue after 2 wk of exposure to terrestrial or aquatic environments. Third, we show that Bt near-isolines modify growth and survivorship of some species of invertebrates. Of the four nontarget invertebrate species fed Bt near-isolines, growth of two closely related trichopterans was not negatively affected, whereas a tipulid crane fly exhibited reduced growth rates, and an isopod exhibited reduced growth and survivorship on the Cry1Ab near-isoline but not on the stacked Cry1Ab + Cry3Bb1 near-isoline. Because of lack of evidence of bioactivity of Bt after 2 wk and because of lack of nontarget effects on the stacked near-isoline, we suggest that tissue-mediated differences, and not the presence of the Cry1Ab protein, caused the different responses among the species. Overall, our results provide evidence that adverse effects to aquatic nontarget shredders involve complex interactions arising from plant genetics and environment that cannot be ascribed to the presence of Cry1Ab proteins.

  13. Effects of 90-Day Feeding of Transgenic Maize BT799 on the Reproductive System in Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    Qian-ying Guo

    2015-12-01

    Full Text Available BT799 is a genetically modified (GM maize plant that expresses the Cry1Ac gene from Bacillus thuringiensis (Bt. The Cry1Ac gene was introduced into maize line Zhen58 to encode the Bt crystal protein and thus produce insect-resistant maize BT799. Expression of Bt protein in planta confers resistance to Lepidopteran pests and corn rootworms. The present study was designed to investigate any potential effects of BT799 on the reproductive system of male rats and evaluate the nutritional value of diets containing BT799 maize grain in a 90-day subchronic rodent feeding study. Male Wistar rats were fed with diets containing BT799 maize flours or made from its near isogenic control (Zhen58 at a concentration of 84.7%, nutritionally equal to the standard AIN-93G diet. Another blank control group of male rats were treated with commercial AIN-93G diet. No significant differences in body weight, hematology and serum chemistry results were observed between rats fed with the diets containing transgenic BT799, Zhen58 and the control in this 13-week feeding study. Results of serum hormone levels, sperm parameters and relative organ/body weights indicated no treatment-related side effects on the reproductive system of male rats. In addition, no diet-related changes were found in necropsy and histopathology examinations. Based on results of the current study, we did not find any differences in the parameters tested in our study of the reproductive system of male rats between BT799 and Zhen58 or the control.

  14. Alteration of leaf metabolism in Bt-transgenic rice (Oryza sativa L.) and its wild type under insecticide stress.

    Science.gov (United States)

    Zhou, Jia; Zhang, Lei; Chang, Yuwei; Lu, Xin; Zhu, Zhen; Xu, Guowang

    2012-08-03

    Insecticide is always used to control the damage from pests, while the potential influence on plants is rarely known. Time-course metabolic changes of wild and Bacillus thuringiensis (Bt) transgenic rice (Oryza sativa L.) plants after insecticide treatment were investigated by using gas chromatography-mass spectrometry (GC-MS). A combined statistical strategy of 2-way ANOVA and multivariate analyses (principal component analysis and hierarchal cluster analysis) was performed to find the stress-associated effects. The results reveal that a wide range of metabolites were dynamically varied in both varieties as a response to insecticide, in multiple metabolic pathways, such as biosynthesis and metabolism of amino acids, carbohydrates, fatty acids, TCA cycle, and the shikimate/phenylpropanoid pathway, and most of the changes were correlated with the exposure time and dependent on the variety. A set of stress defenses were activated, including phytohormone signaling pathway, antioxidant defense system, shikimate-mediated secondary metabolism, and so on. In particular, insecticide led to much stronger regulations of signaling molecules (salicylate and the precursor of jasmonate) and antioxidants (α-tocopherol and dehydroascorbate/ascorbate) in Bt-transgenic variety at the early stage. Our results demonstrated that the Bt-transgenic rice had a more acute and drastic response to insecticide stress than its non-transgenic counterpart in antioxidant system and signaling regulation.

  15. Segregation and expression of transgenes in the progenies of Bt ...

    African Journals Online (AJOL)

    PCR, Southern blotting and Western dot blotting analysis confirmed that cry1Ab gene was transferred to the genome of conventional rice varieties and it was highly expressed in the different progenies of Bt rice crossed to conventional rice varieties. Among these lines, the highest Bt toxin protein content reached 2.88% of ...

  16. Plant Fitness Assessment for Wild Relatives of Insect Resistant Bt-Crops

    Directory of Open Access Journals (Sweden)

    D. K. Letourneau

    2012-01-01

    Full Text Available When field tests of transgenic plants are precluded by practical containment concerns, manipulative experiments can detect potential consequences of crop-wild gene flow. Using topical sprays of bacterial Bacillus thuringiensis larvicide (Bt and larval additions, we measured fitness effects of reduced herbivory on Brassica rapa (wild mustard and Raphanus sativus (wild radish. These species represent different life histories among the potential recipients of Bt transgenes from Bt cole crops in the US and Asia, for which rare spontaneous crosses are expected under high exposure. Protected wild radish and wild mustard seedlings had approximately half the herbivore damage of exposed plants and 55% lower seedling mortality, resulting in 27% greater reproductive success, 14-day longer life-spans, and 118% more seeds, on average. Seed addition experiments in microcosms and in situ indicated that wild radish was more likely to spread than wild mustard in coastal grasslands.

  17. Modeling evolution of resistance of sugarcane borer (Lepidoptera: Crambidae) to transgenic Bt corn.

    Science.gov (United States)

    Kang, J; Huang, F; Onstad, D W

    2014-08-01

    Diatraea saccharalis (F.) (Lepidoptera: Crambidae) is a target pest of transgenic corn expressing Bacillus thuringiensis (Bt) protein, and the first evidence of resistance by D. saccharalis to Cry1Ab corn was detected in a field population in northeast Louisiana in 2004. We used a model of population dynamics and genetics of D. saccharalis to 1) study the effect of interfield dispersal, the first date that larvae enter diapause for overwintering, toxin mortality, the proportion of non-Bt corn in the corn patch, and the area of a crop patch on Bt resistance evolution; and 2) to identify gaps in empirical knowledge for managing D. saccharalis resistance to Bt corn. Increasing, the proportion of corn refuge did not always improve the durability of Bt corn if the landscape also contained sugarcane, sorghum, or rice. In the landscape, which consisted of 90% corn area, 5% sorghum area, and 5% rice area, the durability of single-protein Bt corn was 40 yr when the proportion of corn refuge was 0.2 but 16 yr when the proportion of corn refuge was 0.5. The Bt resistance evolution was sensitive to a change (from Julian date 260 to 272) in the first date larvae enter diapause for overwintering and moth movement. In the landscapes with Bt corn, non-Bt corn, sugarcane, sorghum, and rice, the evolution of Bt resistance accelerated when larvae entered diapause for overwintering early. Intermediate rates of moth movement delayed evolution of resistance more than either extremely low or high rates. This study suggested that heterogeneity in the agrolandscapes may complicate the strategy for managing Bt resistance in D. saccharalis, and designing a Bt resistance management strategy for D. saccharalis is challenging because of a lack of empirical data about overwintering and moth movement.

  18. Plant biotechnology: transgenic crops.

    Science.gov (United States)

    Shewry, Peter R; Jones, Huw D; Halford, Nigel G

    2008-01-01

    Transgenesis is an important adjunct to classical plant breeding, in that it allows the targeted manipulation of specific characters using genes from a range of sources. The current status of crop transformation is reviewed, including methods of gene transfer, the selection of transformed plants and control of transgene expression. The application of genetic modification technology to specific traits is then discussed, including input traits relating to crop production (herbicide tolerance and resistance to insects, pathogens and abiotic stresses) and output traits relating to the composition and quality of the harvested organs. The latter include improving the nutritional quality for consumers as well as the improvement of functional properties for food processing.

  19. The influence of fertilizer level and spore density on arbuscular mycorrhizal colonization of transgenic Bt 11 maize (Zea mays) in experimental microcosms.

    Science.gov (United States)

    Cheeke, Tanya E; Pace, Brian A; Rosenstiel, Todd N; Cruzan, Mitchell B

    2011-02-01

    Crop plants genetically modified for the expression of Bacillus thuringiensis (Bt) insecticidal toxins have broad appeal for reducing insect damage in agricultural systems, yet questions remain about the impact of Bt plants on symbiotic soil organisms. Here, arbuscular mycorrhizal fungal (AMF) colonization of transgenic maize isoline Bt 11 (expressing Cry1Ab) and its non-Bt parental line (Providence) was evaluated under different fertilizer level and spore density scenarios. In a three-way factorial design, Bt 11 and non-Bt maize were inoculated with 0, 40, or 80 spores of Glomus mosseae and treated weekly with 'No' (0 g L(-1) ), 'Low' (0.23 g L(-1) ), or 'High' (1.87 g L(-1) ) levels of a complete fertilizer and grown for 60 days in a greenhouse. While no difference in AMF colonization was detected between the Bt 11 and Providence maize cultivars in the lower spore/higher fertilizer treatments, microcosm experiments demonstrated a significant reduction in AMF colonization in Bt 11 maize roots in the 80 spore treatments when fertilizer was limited. These results confirm previous work indicating an altered relationship between this Bt 11 maize isoline and AMF and demonstrate that the magnitude of this response is strongly dependent on both nutrient supply and AMF spore inoculation level. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  20. Transgenic Bacillus thuringiensis (Bt rice is safer to aquatic ecosystems than its non-transgenic counterpart.

    Directory of Open Access Journals (Sweden)

    Guangsheng Li

    Full Text Available Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems.

  1. Supplemental Control of Lepidopterous Pests on Bt Transgenic Sweet Corn with Biologically-Based Spray Treatments

    OpenAIRE

    Farrar, Robert R.; Shepard, B. Merle; Shapiro, Martin; Hassell, Richard. L; Schaffer, Mark. L.; Smith, Chad. M.

    2009-01-01

    Biologically-based spray treatments, including nucleopolyhedroviruses, neem, and spinosad, were evaluated as supplemental controls for the fall armyworm, Spodoptera frugiperda (J. E. Smith), and corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), on transgenic sweet corn, Zea mays (L.) (Poales: Poaceae), expressing a Cry1Ab toxin from Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt). Overall, transgenic corn supported lower densities of both pests than did nontransg...

  2. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids: a case study on non-target effects.

    Science.gov (United States)

    Xue, Kun; Deng, Su; Wang, RongJiang; Yan, FengMing; Xu, ChongRen

    2008-02-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioassays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines (GK12 and GK19) and their parental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes, were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes. Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches influenced the cotton aphids' searching behaviors effectively; and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

  3. Transgenic Bt cotton driven by the green tissue-specific promoter shows strong toxicity to lepidopteran pests and lower Bt toxin accumulation in seeds.

    Science.gov (United States)

    Wang, Qing; Zhu, Yi; Sun, Lin; Li, Lebin; Jin, Shuangxia; Zhang, Xianlong

    2016-02-01

    A promoter of the PNZIP (Pharbitis nil leucine zipper) gene (1.459 kb) was cloned from Pharbitis nil and fused to the GUS (β-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 (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 μg 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 48.3 μg g(-1) fresh weight respectively. In contrast, seeds of the PNZIP::Cry9C line (PZ1.3) accumulated only 0.26 μg g(-1) 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 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.

  4. Transgenic plants for phytoremediation.

    Science.gov (United States)

    Maestri, Elena; Marmiroli, Nelson

    2011-01-01

    Phytoremediation is a green, sustainable and promising solution to problems of environmental contamination. It entails the use of plants for uptake, sequestration, detoxification or volatilization of inorganic and organic pollutants from soils, water, sediments and possibly air. Phytoremediation was born from the observation that plants possessed physiological properties useful for environmental remediation. This was shortly followed by the application of breeding techniques and artificial selection to genetically improve some of the more promising and interesting species. Now, after nearly 20 years of research, transgenic plants for phytoremediation have been produced, but none have reached commercial existence. Three main approaches have been developed: (1) transformation with genes from other organisms (mammals, bacteria, etc.); (2) transformation with genes from other plant species; and (3) overexpression of genes from the same plant species. Many encouraging results have been reported, even though in some instances results have been contrary to expectations. This review will illustrate the main examples with a critical discussion of what we have learnt from them.

  5. Uptake of Bt endotoxins by nontarget herbivores and higher order arthropod predators: molecular evidence from a transgenic corn agroecosystem.

    Science.gov (United States)

    Harwood, James D; Wallin, William G; Obrycki, John J

    2005-08-01

    The planting of transgenic crops expressing Bacillus thuringiensis endotoxins is widespread throughout the world; the prolific increase in their application exposes nontarget organisms to toxins designed to control pests. To date, studies have focused upon the effects of Bt endotoxins on specific herbivores and detritivores, without consideration of their persistence within arthropod food webs. Here, we report the first quantitative field evaluation of levels of Bt endotoxin within nontarget herbivores and the uptake by higher order arthropods. Antibody-based assays indicated significant quantities of detectable Cry1Ab endotoxin within nontarget herbivores which feed on transgenic corn (including the corn flea beetle, Chaetocnema pulicaria, Japanese beetle, Popillia japonica and southern corn rootworm, Diabrotica undecimpunctata howardi). Furthermore, arthropod predators (Coccinellidae, Araneae, and Nabidae) collected from these agroecosystems also contained significant quantities of Cry1Ab endotoxin indicating its movement into higher trophic levels. This uptake by predators is likely to have occurred by direct feeding on plant material (in predators which are facultatively phytophagous) or the consumption of arthropod prey which contained these proteins. These data indicate that long-term exposure to insecticidal toxins occurs in the field. These levels of exposure should therefore be considered during future risk assessments of transgenic crops to nontarget herbivores and arthropod predators.

  6. Use of maize pollen by adult Chrysoperla carnea (Neuroptera: Chrysopidae) and fate of Cry proteins in Bt-transgenic varieties.

    Science.gov (United States)

    Li, Yunhe; Meissle, Michael; Romeis, Jörg

    2010-02-01

    We investigated the use of maize pollen as food by adult Chrysoperla carnea under laboratory and field conditions. Exposure of the insects to insecticidal Cry proteins from Bacillus thuringiensis (Bt) contained in pollen of transgenic maize was also assessed. Female C. carnea were most abundant in a maize field when the majority of plants were flowering and fresh pollen was abundant. Field-collected females contained an average of approximately 5000 maize pollen grains in their gut at the peak of pollen shedding. Comparable numbers were found in females fed ad libitum maize pollen in the laboratory. Maize pollen is readily used by C. carnea adults. When provided with a carbohydrate source, it allowed the insects to reach their full reproductive potential. Maize pollen was digested mainly in the insect's mid- and hindgut. When Bt maize pollen passed though the gut of C. carnea, 61% of Cry1Ab (event Bt176) and 79% of Cry3Bb1 (event MON 88017) was digested. The results demonstrate that maize pollen is a suitable food source for C. carnea. Even though the pollen grains are not fully digested, the insects are exposed to transgenic insecticidal proteins that are contained in the pollen. Copyright 2009 Elsevier Ltd. All rights reserved.

  7. Transgenic tetraploid Isatis indigotica expressing Bt Cry1Ac and Pinellia ternata agglutinin showed enhanced resistance to moths and aphids.

    Science.gov (United States)

    Xiao, Ying; Wang, Kai; Ding, Ruxian; Zhang, Hanming; Di, Peng; Chen, Junfeng; Zhang, Lei; Chen, Wansheng

    2012-01-01

    Co-expression of multiple genes encoding different kinds of insect resistant proteins has been developed to confer a broader spectrum of pest control. Tetraploid Isatis indigotica Fort was transformed with a plasmid, p3300BP, containing Bacillus thuringiensis Cry1Ac gene (Bt) and Pinellia ternata agglutinin gene (Pta) and the selectable marker herbicide resistance gene (Bar) driven by the CaMV35S promoter via Agrobacterium tumefaciens-mediated transformation. The integration and expression of introduced genes in regenerated transgenic plants were confirmed by PCR and Western blot assays. Insect bioassay test demonstrated transgenic lines had significant inhibition to diamondback moths (Plutella xylostella L.) and peach potato aphids (Myzus persicae Sulzer) simultaneously. Our study reported here would be a great motivation for field culture of tetraploid I. indigotica, also providing an efficient molecular breeding strategy to provide insect tolerant plants.

  8. Overexpression of the Bacillus thuringiensis (Bt) Cry2Aa2 protein in chloroplasts confers resistance to plants against susceptible and Bt-resistant insects.

    Science.gov (United States)

    Kota, M; Daniell, H; Varma, S; Garczynski, S F; Gould, F; Moar, W J

    1999-03-02

    Evolving levels of resistance in insects to the bioinsecticide Bacillus thuringiensis (Bt) can be dramatically reduced through the genetic engineering of chloroplasts in plants. When transgenic tobacco leaves expressing Cry2Aa2 protoxin in chloroplasts were fed to susceptible, Cry1A-resistant (20,000- to 40,000-fold) and Cry2Aa2-resistant (330- to 393-fold) tobacco budworm Heliothis virescens, cotton bollworm Helicoverpa zea, and the beet armyworm Spodoptera exigua, 100% mortality was observed against all insect species and strains. Cry2Aa2 was chosen for this study because of its toxicity to many economically important insect pests, relatively low levels of cross-resistance against Cry1A-resistant insects, and its expression as a protoxin instead of a toxin because of its relatively small size (65 kDa). Southern blot analysis confirmed stable integration of cry2Aa2 into all of the chloroplast genomes (5, 000-10,000 copies per cell) of transgenic plants. Transformed tobacco leaves expressed Cry2Aa2 protoxin at levels between 2% and 3% of total soluble protein, 20- to 30-fold higher levels than current commercial nuclear transgenic plants. These results suggest that plants expressing high levels of a nonhomologous Bt protein should be able to overcome or at the very least, significantly delay, broad spectrum Bt-resistance development in the field.

  9. [Changes in diversity of culturable microorganisms on leaf surface of transgenic Bt cotton].

    Science.gov (United States)

    Wang, Yuan-Ge; Tan, Mao-Yu; Li, Jin-E; Xie, Qing-En; Fan, Zuo-Xiao; Shen, Fa-Fu

    2007-03-01

    In a field study, the quantitative changes of bacterial, actinomycetic and fungal populations on the leaf surface of transgenic Bt cotton (GK-12) and non-transgenic Bt cotton (Simian No. 3) were monitored at seedling, squaring, flowering and boll-opening stages, respectively, and the diversity of bacterial physiological groups was analyzed at flowering and boll-opening stages. The results showed that there was a positive correlation between the quantity of culturable microorganisms and the development of cotton. The total number of bacteria, fungi and actinomyces began to rise at seedling stage, reached its peak at flowering stage, and decreased markedly at boll-opening stage. The Simpson index, Shannon-Wiener index, and evenness index of bacterial physiological groups were higher at flowering stage, but lower at boll-opening stage on GK-12 than on Simian No. 3.

  10. Coping with Ex-ante Regulations for Planting Bt Maize: The Portuguese Experience

    NARCIS (Netherlands)

    Skevas, T.; Wesseler, J.H.H.; Fevereiro, P.

    2009-01-01

    This article investigates the attitude and practices of Bt and non-Bt maize farmers in Portugal. Thirty-seven Bt maize farmers were interviewed, representing 22.5% of the total number of Bt maize notifications in the country and 31.5% of the total area planted with Bt maize in 2007. Additionally, 66

  11. Transgenic Bacillus thuringiensis (Bt) rice is safer to aquatic ecosystems than its non-transgenic counterpart

    National Research Council Canada - National Science Library

    Li, Guangsheng; Wang, Yongmo; Liu, Biao; Zhang, Guoan

    2014-01-01

    .... In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field...

  12. Impact of corn earworm injury on yield of transgenic corn producing Bt toxins in the Carolinas.

    Science.gov (United States)

    Reay-Jones, Francis P F; Reisig, Dominic D

    2014-06-01

    Transgenic corn, Zea mays L., hybrids expressing insecticidal Cry proteins from Bacillus thuringiensis (Bt) and insecticide applications to suppress injury from Helicoverpa zea (Boddie) were evaluated in Florence, SC, and in Plymouth, NC, in 2012 and 2013. Based on kernel area injured, insecticide applications (chlorantraniliprole) every 3-4 d from R1 until H. zea had cycled out of corn reduced injury by 80-93% in Florence and 94-95% in Plymouth. Despite intensive applications of insecticide (13-18 per trial), limited injury still occurred in all treated plots in 2012, except in DKC 68-03 (Genuity VT Double PRO), based on kernels injured (both locations) and proportion of injured ears (Florence only). In 2013, ear injury was low in Plymouth, with no kernel injury in any insecticide-treated plots, except P1498R (non-Bt) and P1498YHR (Optimum Intrasect). Injury in Florence in 2013 did not occur in treated plots of DKC 68-04 (non-Bt), DKC 68-03 (Genuity VT Double PRO), and N785-3111 (Agrisure Viptera). Yields were not significantly affected by insecticide treatment and were not statistically different among near-isolines with and without Bt traits. Yields were not significantly associated with kernel injury based on regression analyses. The value of using Bt corn hybrids to manage H. zea is discussed.

  13. Cross-pollination of nontransgenic corn ears with transgenic Bt corn: efficacy against lepidopteran pests and implications for resistance management.

    Science.gov (United States)

    Burkness, E C; O'Rourke, P K; Hutchison, W D

    2011-10-01

    The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000. Non-Bt and Bt hybrids (maternal plants) were cross-pollinated with pollen from both non-Bt and Bt hybrids (paternal plants) to create four crosses. Subsequent crosses were evaluated for efficacy in the field against European corn borer, Ostrinia nubilalis (Hübner), and corn earworm, Helicoverpa zea (Boddie), and in laboratory bioassays against O. nubilalis. Field studies indicated that crosses with maternal Bt plants led to low levels of survival for both O. nubilalis and H. zea compared with the non-Bt x non-Bt cross. However, the cross between non-Bt ears and Bt pollen led to survival rates of 43 and 63% for O. nubilalis and H. zea larvae, respectively. This intermediate level of survival also was reflected in the number of kernels damaged. Laboratory bioassays for O. nubilalis, further confirmed field results with larval survival on kernels from the cross between non-Bt ears and Bt pollen reaching 60% compared with non-Bt crossed with non-Bt. These results suggest that non-Bt refuge plants, when planted in proximity to Bt plants, and cross-pollinated, can result in sublethal exposure of O. nubilalis and H. zea larvae to Bt and may undermine the high-dose/refuge resistance management strategy for corn hybrids expressing Cry1Ab.

  14. Transgenic Bacillus thuringiensis (Bt) chickpea: India's most wanted ...

    African Journals Online (AJOL)

    Sumita

    2013-09-25

    Sep 25, 2013 ... control this devastating pest. Breeding for development of resistant lines is restricted by lack of .... to control H. armigera in chickpea. However, the efficiency of the IPM strategies depends on various .... ing particle gun bonbardment. Plant Cell Rep. 26:755-63. International Crops Research Institute for Semi ...

  15. Supplemental Control of Lepidopterous Pests on Bt Transgenic Sweet Corn with Biologically-Based Spray Treatments

    Science.gov (United States)

    Farrar, Robert R.; Shepard, B. Merle; Shapiro, Martin; Hassell, Richard. L; Schaffer, Mark. L.; Smith, Chad. M.

    2009-01-01

    Biologically-based spray treatments, including nucleopolyhedroviruses, neem, and spinosad, were evaluated as supplemental controls for the fall armyworm, Spodoptera frugiperda (J. E. Smith), and corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), on transgenic sweet corn, Zea mays (L.) (Poales: Poaceae), expressing a Cry1Ab toxin from Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt). Overall, transgenic corn supported lower densities of both pests than did nontransgenic corn. Control of the fall armyworm was improved in both whorl-stage and tassel-stage corn by the use of either a nucleopolyhedrovirus or neem, but the greatest improvement was seen with spinosad. Only spinosad consistently reduced damage to ears, which was caused by both pest species. In general, efficacy of the spray materials did not differ greatly between transgenic and nontransgenic corn. PMID:19611255

  16. Epigenetic silencing in transgenic plants.

    Science.gov (United States)

    Rajeevkumar, Sarma; Anunanthini, Pushpanathan; Sathishkumar, Ramalingam

    2015-01-01

    Epigenetic silencing is a natural phenomenon in which the expression of genes is regulated through modifications of DNA, RNA, or histone proteins. It is a mechanism for defending host genomes against the effects of transposable elements and viral infection, and acts as a modulator of expression of duplicated gene family members and as a silencer of transgenes. A major breakthrough in understanding the mechanism of epigenetic silencing was the discovery of silencing in transgenic tobacco plants due to the interaction between two homologous promoters. The molecular mechanism of epigenetic mechanism is highly complicated and it is not completely understood yet. Two different molecular routes have been proposed for this, that is, transcriptional gene silencing, which is associated with heavy methylation of promoter regions and blocks the transcription of transgenes, and post-transcriptional gene silencing (PTGS), the basic mechanism is degradation of the cytosolic mRNA of transgenes or endogenous genes. Undesired transgene silencing is of major concern in the transgenic technologies used in crop improvement. A complete understanding of this phenomenon will be very useful for transgenic applications, where silencing of specific genes is required. The current status of epigenetic silencing in transgenic technology is discussed and summarized in this mini-review.

  17. Effect of vegetation of transgenic Bt rice lines and their straw amendment on soil enzymes, respiration, functional diversity and community structure of soil microorganisms under field conditions.

    Science.gov (United States)

    Fang, Hua; Dong, Bin; Yan, Hu; Tang, Feifan; Wang, Baichuan; Yu, Yunlong

    2012-01-01

    With the development of transgenic crops, there is an increasing concern about the possible adverse effects of their vegetation and residues on soil environmental quality. This study was carried out to evaluate the possible effects of the vegetation of transgenic Bt rice lines Huachi B6 (HC) and TT51 (TT) followed by the return of their straw to the soil on soil enzymes (catalase, urease, neutral phosphatase and invertase), anaerobic respiration activity, microbial utilization of carbon substrates and community structure, under field conditions. The results indicated that the vegetation of the two transgenic rice lines (HC and TT) and return of their straw had few adverse effects on soil enzymes and anaerobic respiration activity compared to their parent and distant parent, although some transient differences were observed. The vegetation and subsequent straw amendment of Bt rice HC and TT did not appear to have a harmful effect on the richness, evenness and community structure of soil microorganisms. No different pattern of impact due to plant species was found between HC and TT. It could be concluded that the vegetation of transgenic Bt rice lines and the return of their straw as organic fertilizer may not alter soil microbe-mediated functions.

  18. Transgenic Bt Cotton Does Not Disrupt the Top-Down Forces Regulating the Cotton Aphid in Central China.

    Science.gov (United States)

    Yao, Yong-Sheng; Han, Peng; Niu, Chang-Ying; Dong, Yong-Cheng; Gao, Xi-Wu; Cui, Jin-Jie; Desneux, Nicolas

    2016-01-01

    Top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. In the context of prevalent adoption of transgenic Bt crops that produce insecticidal Cry proteins derived from Bacillus thuringiensis (Bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the Bt crops. We explored how Bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-target pest species, the cotton aphid Aphis gossypii Glover, using a comparative approach (i.e. Bt cotton vs. conventional cotton) under field conditions. To determine top-down forces, we manipulated predation/parasitism exposure of the aphid to their natural enemies using exclusion cages. We found that the aphid population growth was strongly suppressed by the dominant natural enemies including Coccinellids, spiders and Aphidiines parasitoids. Coccinellids, spiders and the assemblage of other arthropod natural enemies (mainly lacewings and Hemipteran bugs) are similarly abundant in both plots, but with the parasitoid mummies less abundant in Bt cotton plots compared to the conventional cotton plots. However, the lower abundance of parasitoids in Bt cotton plots alone did not translate into differential top-down control on A. gossypii populations compared to conventional ones. Overall, the top-down forces were equally strong in both plots. We conclude that transgenic Bt cotton does not disrupt the top-down forces regulating the cotton aphid in central China.

  19. Transgenic Bt Cotton Does Not Disrupt the Top-Down Forces Regulating the Cotton Aphid in Central China.

    Directory of Open Access Journals (Sweden)

    Yong-Sheng Yao

    Full Text Available Top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. In the context of prevalent adoption of transgenic Bt crops that produce insecticidal Cry proteins derived from Bacillus thuringiensis (Bt, it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the Bt crops. We explored how Bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-target pest species, the cotton aphid Aphis gossypii Glover, using a comparative approach (i.e. Bt cotton vs. conventional cotton under field conditions. To determine top-down forces, we manipulated predation/parasitism exposure of the aphid to their natural enemies using exclusion cages. We found that the aphid population growth was strongly suppressed by the dominant natural enemies including Coccinellids, spiders and Aphidiines parasitoids. Coccinellids, spiders and the assemblage of other arthropod natural enemies (mainly lacewings and Hemipteran bugs are similarly abundant in both plots, but with the parasitoid mummies less abundant in Bt cotton plots compared to the conventional cotton plots. However, the lower abundance of parasitoids in Bt cotton plots alone did not translate into differential top-down control on A. gossypii populations compared to conventional ones. Overall, the top-down forces were equally strong in both plots. We conclude that transgenic Bt cotton does not disrupt the top-down forces regulating the cotton aphid in central China.

  20. Biological activity of Bt proteins expressed in different structures of transgenic corn against Spodoptera frugiperda

    Directory of Open Access Journals (Sweden)

    Daniel Bernardi

    2016-06-01

    Full Text Available ABSTRACT: Spodoptera frugiperda (J. E. Smith is the main target pest of Bt corn technologies, such as YieldGard VT PRO(tm (Cry1A.105/Cry2Ab2 and PowerCore(tm (Cry1A.105/Cry2Ab2/Cry1F. In this study, it was evaluated the biological activity of Bt proteins expressed in different plant structures of YieldGard VT PRO(tm and PowerCore(tm corn against S. frugiperda . Complete mortality of S. frugiperda neonates was observed on leaf-disc of both Bt corn technologies. However, the mortality in silks and grains was lower than 50 and 6%, respectively. In addition, more than 49% of the surviving larvae in silks and grains completed the biological cycle. However, all life table parameters were negatively affected in insects that developed in silks and grains of both Bt corn events. In summary, the low biological activity of Bt proteins expressed on silks and grains of YieldGard VT PRO(tm and PowerCore(tm corn can contribute to the resistance evolution in S. frugiperda populations.

  1. Cry1F protein not detected in soil after three years of transgenic Bt corn (1507 corn) use.

    Science.gov (United States)

    Shan, Guomin; Embrey, Shawna K; Herman, Rod A; McCormick, Ronald

    2008-02-01

    To evaluate the potential of Bacillus thuringiensis (Bt) Cry1F protein accumulation in soil, transgenic corn containing event DAS-01507-1 encoding the cry1F gene was grown in three field sites for 3 consecutive yr, and the corn plants were incorporated into the soil through postseason tillage or no tillage each year. Soil samples were collected from these fields, and the level of Cry1F protein in these samples was determined using an enzyme-linked immunosorbent assay (ELISA) with a synthetic invertebrate gut fluid as an extraction buffer. The ELISA was validated in soil matrices over the concentration range of 18-180 ng/g dry weight, with a limit of detection of 4.5 ng/g dry weight. The assay was shown to have good accuracy and precision. No detectable Cry1F protein was found in any of the soil samples collected from the Cry1F corn fields. Soil also was bioassayed, and no biological activity was observed against Heliothis virescens neonates. These results indicate that the level of Cry1F protein accumulated in soil after 3-yr continuous planting of transgenic Cry1F corn is negligible.

  2. What are farmers really planting? Measuring the presence and effectiveness of Bt cotton in Pakistan.

    Directory of Open Access Journals (Sweden)

    David J Spielman

    Full Text Available Genetically modified, insect-resistant Bacillus thuringiensis (Bt cotton is cultivated extensively in Pakistan. Past studies, however, have raised concerns about the prevalence of Bt cotton varieties possessing weak or nonperforming insect-resistance traits conferred by the cry gene. We examine this issue using data drawn from a representative sample of cotton-growing households that were surveyed in six agroclimatic zones spanning 28 districts in Pakistan in 2013, as well as measurements of Cry protein levels in cotton tissue samples collected from the sampled households' main fields. The resultant dataset combines information from 593 sampled households with corresponding plant tissue diagnostics from 70 days after sowing, as well as information from 589 sampled households with corresponding diagnostics from 120 days after sowing. Our analysis indicates that 11 percent of farmers believed they were cultivating Bt cotton when, in fact, the Cry toxin was not present in the tested tissue at 70 days after sowing (i.e., a Type I error. The analysis further indicates that 5 percent of farmers believed they were cultivating non-Bt cotton when, in fact, the Cry toxin was present in the tested tissue (i.e., a Type II error. In addition, 17 percent of all sampled farmers were uncertain whether or not they were cultivating Bt cotton. Overall, 33 percent of farmers either did not know or were mistaken in their beliefs about the presence of the cry gene in the cotton they cultivated. Results also indicate that toxic protein levels in the plant tissue samples occurred below threshold levels for lethality in a significant percentage of cases, although these measurements may also be affected by factors related to tissue sample collection, handling, storage, and testing procedures. Nonetheless, results strongly suggest wide variability both in farmers' beliefs and in gene expression. Such variability has implications for policy and regulation in Pakistan

  3. Efficient generation of marker-free transgenic rice plants using an improved transposon-mediated transgene reintegration strategy.

    Science.gov (United States)

    Gao, Xiaoqing; Zhou, Jie; Li, Jun; Zou, Xiaowei; Zhao, Jianhua; Li, Qingliang; Xia, Ran; Yang, Ruifang; Wang, Dekai; Zuo, Zhaoxue; Tu, Jumin; Tao, Yuezhi; Chen, Xiaoyun; Xie, Qi; Zhu, Zengrong; Qu, Shaohong

    2015-01-01

    Marker-free transgenic plants can be developed through transposon-mediated transgene reintegration, which allows intact transgene insertion with defined boundaries and requires only a few primary transformants. In this study, we improved the selection strategy and validated that the maize (Zea mays) Activator/Dissociation (Ds) transposable element can be routinely used to generate marker-free transgenic plants. A Ds-based gene of interest was linked to green fluorescent protein in transfer DNA (T-DNA), and a green fluorescent protein-aided counterselection against T-DNA was used together with polymerase chain reaction (PCR)-based positive selection for the gene of interest to screen marker-free progeny. To test the efficacy of this strategy, we cloned the Bacillus thuringiensis (Bt) δ-endotoxin gene into the Ds elements and transformed transposon vectors into rice (Oryza sativa) cultivars via Agrobacterium tumefaciens. PCR assays of the transposon empty donor site exhibited transposition in somatic cells in 60.5% to 100% of the rice transformants. Marker-free (T-DNA-free) transgenic rice plants derived from unlinked germinal transposition were obtained from the T1 generation of 26.1% of the primary transformants. Individual marker-free transgenic rice lines were subjected to thermal asymmetric interlaced-PCR to determine Ds(Bt) reintegration positions, reverse transcription-PCR and enzyme-linked immunosorbent assay to detect Bt expression levels, and bioassays to confirm resistance against the striped stem borer Chilo suppressalis. Overall, we efficiently generated marker-free transgenic plants with optimized transgene insertion and expression. The transposon-mediated marker-free platform established in this study can be used in rice and possibly in other important crops. © 2015 American Society of Plant Biologists. All Rights Reserved.

  4. Survival and development of a stored-product pest, Sitophilus zeamais (Coleoptera: Curculionidae), and its natural enemy, the parasitoid Lariophagus distinguendus (Hymenoptera: Pteromalidae), on transgenic Bt maize.

    Science.gov (United States)

    Hansen, Lise S; Lövei, Gábor L; Székács, András

    2013-05-01

    The effect of transgenic maize (Zea mays L.) containing a lepidopteran-specific Bt toxin on a stored-product pest, Sitophilus zeamais Motschulsky, and its parasitoid, Lariophagus distinguendus Förster, was examined in the laboratory to test the impact of transgenic maize on stored-product pests and their biological control. Weevils were not harmfully affected by transgenic Bt maize in their development characteristics (development time, body mass), and females emerging from transgenic maize kernels were larger. However, significantly fewer parasitoid females emerged from weevils that developed in transgenic kernels, although parasitoids did not develop more slowly and were not different in size or mass from their conspecifics emerging from hosts in non-transgenic maize kernels. The emergence of female parasitoids was reduced in transgenic Bt maize, and this effect cannot be explained by the known lepidopteran-specific toxicity of Bt Cry1Ab toxin. © 2012 Society of Chemical Industry.

  5. Identification of top-down forces regulating cotton aphid population growth in transgenic Bt cotton in central China.

    Directory of Open Access Journals (Sweden)

    Peng Han

    Full Text Available The cotton aphid Aphis gossypii Glover is the main aphid pest in cotton fields in the Yangtze River Valley Cotton-planting Zone (YRZ in central China. Various natural enemies may attack the cotton aphid in Bt cotton fields but no studies have identified potential specific top-down forces that could help manage this pest in the YRZ in China. In order to identify possibilities for managing the cotton aphid, we monitored cotton aphid population dynamics and identified the effect of natural enemies on cotton aphid population growth using various exclusion cages in transgenic Cry1Ac (Bt+CpTI (Cowpea trypsin inhibitor cotton field in 2011. The aphid population growth in the open field (control was significantly lower than those protected or restricted from exposure to natural enemies in the various exclusion cage types tested. The ladybird predator Propylaea japonica Thunberg represented 65% of Coccinellidae predators, and other predators consisted mainly of syrphids (2.1% and spiders (1.5%. The aphid parasitoids Aphidiines represented 76.7% of the total count of the natural enemy guild (mainly Lysiphlebia japonica Ashmead and Binodoxys indicus Subba Rao & Sharma. Our results showed that P. japonica can effectively delay the establishment and subsequent population growth of aphids during the cotton growing season. Aphidiines could also reduce aphid density although their impact may be shadowed by the presence of coccinellids in the open field (likely both owing to resource competition and intraguild predation. The implications of these results are discussed in a framework of the compatibility of transgenic crops and top-down forces exerted by natural enemy guild.

  6. Efficient Generation of Marker-Free Transgenic Rice Plants Using an Improved Transposon-Mediated Transgene Reintegration Strategy1

    Science.gov (United States)

    Gao, Xiaoqing; Zhou, Jie; Li, Jun; Zou, Xiaowei; Zhao, Jianhua; Li, Qingliang; Xia, Ran; Yang, Ruifang; Wang, Dekai; Zuo, Zhaoxue; Tu, Jumin; Tao, Yuezhi; Chen, Xiaoyun; Xie, Qi; Zhu, Zengrong

    2015-01-01

    Marker-free transgenic plants can be developed through transposon-mediated transgene reintegration, which allows intact transgene insertion with defined boundaries and requires only a few primary transformants. In this study, we improved the selection strategy and validated that the maize (Zea mays) Activator/Dissociation (Ds) transposable element can be routinely used to generate marker-free transgenic plants. A Ds-based gene of interest was linked to green fluorescent protein in transfer DNA (T-DNA), and a green fluorescent protein-aided counterselection against T-DNA was used together with polymerase chain reaction (PCR)-based positive selection for the gene of interest to screen marker-free progeny. To test the efficacy of this strategy, we cloned the Bacillus thuringiensis (Bt) δ-endotoxin gene into the Ds elements and transformed transposon vectors into rice (Oryza sativa) cultivars via Agrobacterium tumefaciens. PCR assays of the transposon empty donor site exhibited transposition in somatic cells in 60.5% to 100% of the rice transformants. Marker-free (T-DNA-free) transgenic rice plants derived from unlinked germinal transposition were obtained from the T1 generation of 26.1% of the primary transformants. Individual marker-free transgenic rice lines were subjected to thermal asymmetric interlaced-PCR to determine Ds(Bt) reintegration positions, reverse transcription-PCR and enzyme-linked immunosorbent assay to detect Bt expression levels, and bioassays to confirm resistance against the striped stem borer Chilo suppressalis. Overall, we efficiently generated marker-free transgenic plants with optimized transgene insertion and expression. The transposon-mediated marker-free platform established in this study can be used in rice and possibly in other important crops. PMID:25371551

  7. Will transgenic plants adversely affect the environment?

    Indian Academy of Sciences (India)

    Unknown

    Bt pollen (0%). Mortality at 120 ..... leaf beetles and potato leafhoppers showed preferences for certain soybean varieties. but these effects ..... organisms involved in plant health, litter decomposition and nutrient cycling. The potential impacts of ...

  8. INSECTICIDAL TOXIN FROM BACILLUS THURINGIENSIS IS RELEASED FROM ROOTS OF TRANSGENIC BT CORN IN VITRO AND IN SITU. (R826107)

    Science.gov (United States)

    AbstractThe insecticidal toxin encoded by the cry1Ab gene from Bacillus thuringiensis was released in root exudates from transgenic Bt corn during 40 days of growth in soil amended to 0, 3, 6, 9, or 12% (v/v) with montmorillonite or kaolinite in a...

  9. Detection and quantitation of genetically modified maize (Bt-176 transgenic maize) by applying ligation detection reaction and universal array technology.

    Science.gov (United States)

    Bordoni, Roberta; Mezzelani, Alessandra; Consolandi, Clarissa; Frosini, Andrea; Rizzi, Ermanno; Castiglioni, Bianca; Salati, Claudia; Marmiroli, Nelson; Marchelli, Rosangela; Rossi Bernardi, Luigi; Battaglia, Cristina; De Bellis, Gianluca

    2004-03-10

    We have applied the ligation detection reaction (LDR) combined with a universal array approach to the detection and quantitation of the polymerase chain reaction (PCR) amplified cry1A(b) gene from Bt-176 transgenic maize. We demonstrated excellent specificity and high sensitivity. Down to 0.5 fmol (nearly 60 pg) of PCR amplified transgenic material was unequivocally detected with excellent linearity within the 0.1-2.0% range with respect to wild-type maize. We suggest the feasibility of extending the LDR/universal array format to detect in parallel several transgenic sequences that are being developed for food applications.

  10. Climate change and genetically modified insecticidal plants. Plant-herbivore interactions and secondary chemistry of Bt Cry1Ac-toxin producing oilseed rape (Brassica napus L.) under elevated CO{sub 2} or O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Himanen, S.

    2008-07-01

    Transgenic insect-resistant plants producing Bacillus thuringiensis (Bt) crystalline endotoxins are the first commercial applications of genetically modified crops and their use has steadily expanded over the last ten years. Together with the expanding agricultural use of transgenic crops, climate change is predicted to be among the major factors affecting agriculture in the coming years. Plants, herbivores and insects of higher trophic levels are all predicted to be affected by the current atmospheric climate change. However, only very few studies to date have addressed the sustained use and herbivore interactions of Bt-producing plants under the influence of these abiotic factors. The main objective of this study was to comparatively assess the performance of a Bt Cry1Ac toxin-producing oilseed rape line and its non-transgenic parent line in terms of vegetative growth and allocation to secondary defence compounds (glucosinolates and volatile terpenoids), and the performance of Bt-target and nontarget insect herbivores as well as tritrophic interaction functioning on these lines. For this, several growth chamber experiments with vegetative stage non-Bt and Bt plants facing exposures to doubled atmospheric CO{sub 2} level alone or together with increased temperature and different regimes of elevated O{sub 3} were conducted. The main hypothesis of this work was that Bt-transgenic plants have reduced performance or allocation to secondary compounds due to the cost of producing Bt toxin under changed abiotic environments. The Bt-transgenic oilseed rape line exhibited slightly delayed vegetative growth and had increased nitrogen and reduced carbon content compared to the non-transgenic parent line, but the physiological responses (i.e. biomass gain and photosynthesis) of the plant lines to CO{sub 2} and O{sub 3} enhancements were equal. Two aphid species, non-susceptible to Bt Cry1Ac, showed equal performance and reproduction on both plant lines under elevated CO{sub 2

  11. Reproduction of root knot nematode (Meloidogyne incognita) on Bt ...

    African Journals Online (AJOL)

    SARAH

    2013-09-30

    Sep 30, 2013 ... ELISA detected Bt protein in soil and roots of Bt cotton but not in HART 89M and isoline plant tissues and soil. Reaction of Bt cotton and isoline to M. incognita was different with the transgenic cotton being more susceptible to RKN. HART 89M was more resistant to RKN infection ... borne fungal pathogens.

  12. Will transgenic plants adversely affect the environment?

    Indian Academy of Sciences (India)

    In general, it seems that large-scale implementation of transgenic insecticidal and herbicide tolerant plants do not display considerable negative effects on the environments and, moreover, at least some transgenic plants can improve the corresponding environments and human health because their production considerably ...

  13. Fungi of the Fusarium genus in the grains of conventional hybrids and transgenic Bt-hybrids of maize (Zea mays L.) in the Czech Republic

    National Research Council Canada - National Science Library

    Kmoch, Martin; Šafránková, Ivana; Holková, Ludmila; Polišenská, Ivana; Krédl, Zdeněk; Pokorný, Radovan

    .... This study focuses on determining the species range of Fusarium fungi in naturally infected stands of conventional hybrids and transgenic Bt-hybrids of maize in the Czech Republic during 2008 and 2009...

  14. Transgenic rice plants expressing cry1Ia5 gene are resistant to stem borer (Chilo agamemnon).

    Science.gov (United States)

    Moghaieb, Reda E A

    2010-01-01

    The stem borer, Chilo agamemnon Bles., is the most serious insect pest in rice fields of the Egyptian Nile Delta. To induce rice plant resistance to Chilo agamemnon, the cry1Ia5 gene was introduced to rice plants (Oryza sativa L.). The integration of the cry1Ia5 gene into the plant genome was confirmed using PCR and Southern blot analyses. The obtained plantlets were transferred to the greenhouse until seeds were collected. Northern blot analysis of the T1 plants confirmed the expression of the cry1Ia5 gene. The insecticidal activity of the transgenic plants against the rice stem borer Chilo agamemnon were tested. The third larval instars were fed on stem cuts from three transgenic lines (L1, L2 and L3) as well as cuts from the control (gfp-transgenic) plants for one week and the mortality percentage was daily recorded. Transgenic line-3 showed the highest mortality percentage after one day (50%) followed by L2 (25%) then L1 (0%). Two days post treatment the mortality percentage increased to 70, 45 and 25% for transgenic lines 1, 2 and 3 respectively. Mortality of 100% was recorded four days post treatment, while those fed on the gfp-transgenic rice (control) showed 0% mortality. Thus, transgenic plants showed high resistance to stem borers and can serve as a novel genetic resource in breeding programs. Transgenic plants expressing BT protein were normal in phenotype with as good seed setting as the nontransgenic control plants.

  15. A proteomic analysis of seeds from Bt-transgenic Brassica napus and hybrids with wild B. juncea.

    Science.gov (United States)

    Liu, Yongbo; Zhang, Ying-Xue; Song, Song-Quan; Li, Junsheng; Neal Stewart, C; Wei, Wei; Zhao, Yujie; Wang, Wei-Qing

    2015-10-21

    Transgene insertions might have unintended side effects on the transgenic host, both crop and hybrids with wild relatives that harbor transgenes. We employed proteomic approaches to assess protein abundance changes in seeds from Bt-transgenic oilseed rape (Brassica napus) and its hybrids with wild mustard (B. juncea). A total of 24, 15 and 34 protein spots matching to 23, 13 and 31 unique genes were identified that changed at least 1.5 fold (p transgenic (tBN) and non-transgenic (BN) oilseed rape, between hybrids of B. juncea (BJ) × tBN (BJtBN) and BJ × BN (BJBN) and between BJBN and BJ, respectively. Eight proteins had higher abundance in tBN than in BN. None of these proteins was toxic or nutritionally harmful to human health, which is not surprising since the seeds are not known to produce toxic proteins. Protein spots varying in abundance between BJtBN and BJBN seeds were the same or homologous to those in the respective parents. None of the differentially-accumulated proteins between BJtBN and BJBN were identical to those between tBN and BN. Results indicated that unintended effects resulted from transgene flow fell within the range of natural variability of hybridization and those found in the native host proteomes.

  16. Transgenic plants with enhanced growth characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-09-06

    The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

  17. Transgenic plants with enhanced growth characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2018-01-09

    The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

  18. Development of a novel-type transgenic cotton plant for control of cotton bollworm.

    Science.gov (United States)

    Yue, Zhen; Liu, Xiaoguang; Zhou, Zijing; Hou, Guangming; Hua, Jinping; Zhao, Zhangwu

    2016-08-01

    The transgenic Bt cotton plant has been widely planted throughout the world for the control of cotton budworm Helicoverpa armigera (Hubner). However, a shift towards insect tolerance of Bt cotton is now apparent. In this study, the gene encoding neuropeptide F (NPF) was cloned from cotton budworm H. armigera, an important agricultural pest. The npf gene produces two splicing mRNA variants-npf1 and npf2 (with a 120-bp segment inserted into the npf1 sequence). These are predicted to form the mature NPF1 and NPF2 peptides, and they were found to regulate feeding behaviour. Knock down of larval npf with dsNPF in vitro resulted in decreases of food consumption and body weight, and dsNPF also caused a decrease of glycogen and an increase of trehalose. Moreover, we produced transgenic tobacco plants transiently expressing dsNPF and transgenic cotton plants with stably expressed dsNPF. Results showed that H. armigera larvae fed on these transgenic plants or leaves had lower food consumption, body size and body weight compared to controls. These results indicate that NPF is important in the control of feeding of H. armigera and valuable for production of potential transgenic cotton. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  19. Transgenic sorghum plants via microprojectile bombardment.

    OpenAIRE

    Casas, A M; Kononowicz, A K; Zehr, U B; Tomes, D T; Axtell, J. D.; Butler, L. G.; Bressan, R. A.; Hasegawa, P M

    1993-01-01

    Transgenic sorghum plants have been obtained after microprojectile bombardment of immature zygotic embryos of a drought-resistant sorghum cultivar, P898012. DNA delivery parameters were optimized based on transient expression of R and C1 maize anthocyanin regulatory elements in scutellar cells. The protocol for obtaining transgenic plants consists of the delivery of the bar gene to immature zygotic embryos and the imposition of bialaphos selection pressure at various stages during culture, fr...

  20. Legal and regulatory concerns about transgenic plants in Brazil.

    Science.gov (United States)

    Fontes, Eliana M G

    2003-06-01

    Brazil has a biosafety law that was approved in 1995. This law provides for a horizontal type of regulation that coordinates other existing regulatory frameworks in the areas of agriculture, health and environment. Various federal government departments are responsible for implementing the law. The National Technical Biosafety Commission is the national competent authority on biosafety with overall responsibility. In the case of Bt plants or any insecticidal organism, the Agrochemical Law also applies and authorization for laboratory, greenhouse and field studies must be obtained from the Plant Protection Secretariat, the Brazilian Institute of Environment and the National Agency of Health. Furthermore, the National Environmental Council must issue a license for commercialization of any GMO. There is pressure needed for capacity building and to harmonize the regulatory and administrative frameworks among the different federal departments involved. Some perspectives and challenges for the commercial registration of transgenic crops are discussed.

  1. Production of transgenic kiwifruit plants harboring the SbtCry1Ac gene.

    Science.gov (United States)

    Zhang, H Y; Liu, H M; Liu, X Z

    2015-07-28

    The kiwifruit (Actinidia chinensis Planch.) is an economically and nutritionally important fruit crop that has a remarkably high vitamin C content and is popular throughout the world. However, kiwifruit plants are vulnerable to attack from pests, and effective pest control is urgently required. Transgenic kiwifruit plants containing the synthetic chimeric gene SbtCry1Ac that encodes the insecticidal protein btCrylAc were obtained through an Agrobacterium-mediated transformation of kiwifruit leaf discs. The kanamycin resistance of the transgenic plants was then analyzed. Results from polymerase chain reactions and genomic DNA Southern blot analyses indicated that SbtCrylAc had been integrated into the genomes of these plants. The results of insect bioassays revealed that the average Oraesia excavate inhibition rate of plants tested at 10 days post-infestation was 75.2%. To our knowledge, this is the first study that has developed insect-resistant transgenic kiwifruit plants.

  2. Maize–planting date interaction and effect of Bt maize on European ...

    African Journals Online (AJOL)

    A study was conducted to determine the influence of planting date and transgenic maize on maize yield following stalk injury by European corn borer, Ostrinia nubilalis (Hubner). Transgenic and non-transgenic maize hybrids with short- and full-season maturity were planted in late April, mid-May and early June from 2006 to ...

  3. [Effect of plantation of transgenic Bt cotton on the amount of rhizospheric soil microorganism and bacterial diversity in the cotton region of Yellow River basin].

    Science.gov (United States)

    Na, Ri-Su; Yu, Hong; Yang, Dian-Lin; Zhao, Jian-Ning; Li, Gang; Na, Bu-Qi; Liu, Ling

    2011-01-01

    Traditional culture-dependent method and PCR-DGGE were adopted to investigate the amount of microorganism and bacterial diversity in rhizospheric soil of transgenic Bt cotton in four provinces of Yellow River basin at four growth stages, i.e., 30, 60, 90, and 120 days after sowing. In the same province and at the same growth stage, no significant difference was observed in the amount of microorganism in rhizospheric soils of transgenic and non-transgenic Bt cottons. Within the same province the amount of microorganism was mainly affected by growth stage; while in different provinces, it was greatly affected by regional conditions. In the four provinces, the bacterial diversity in rhizospheric soil of transgenic Bt cotton was abundant; and in the same province and at the same growth stage, there were no significant differences in the Shannon index, evenness, and richness of bacteria in rhizospheric soils of transgenic and non-transgenic Bt cottons. In different provinces, the bacterial diversity in rhizospheric soils was dependent on regional conditions, but the difference was rather small.

  4. [Bt gene flow of transgeic cotton].

    Science.gov (United States)

    Shen, F F; Yu, Y J; Zhang, X K; Bi, J J; Yin, C Y

    2001-01-01

    This study was carried out to determine the gene flow of transgenic cotton under Chinese ecological environment. Transgenic cotton GK-12 containing the marker gene NPTII and Bt gene was planted in the 6 x 6 m2 plot, non-transgenic cotton CCRC 12 and Xinmian 13 were planted respectively around them. At varying distances from transgenic cotton, seeds produced by the non-transgenic cotton were collected and screened for marker gene and Bt gene using kanamycine sulphate and Dot-ELISA method. PCR technique was also used in some seeds to screen Bt gene. The result indicated that gene flow was found to be high at 0-6 m, and to decrease with distances; however gene flow occurred up to distance of 36 m from the transgenic cotton plot. Bt gene flow at 3-6 m increased with increasing the diversity of transgenic cotton in the plot, but gene flow increased little at long distance. The gene flow between species was lower than between cultivars at 0-6 m, and occurred at the distance of 72 m from transgenic plot. 72 m buffer zones would serve to limit gene flow of transgenic cotton from small-scale field test. The possibility of escapes of engineered gene to wild relatives of cotton species was also discussed.

  5. The ecological risks of transgenic plants.

    Science.gov (United States)

    Giovannetti, Manuela

    2003-01-01

    Biotechnologies have been utilized "ante litteram" for thousands of years to produce food and drink and genetic engineering techniques have been widely applied to produce many compounds for human use, from insulin to other medicines. The debate on genetically modified (GM) organisms broke out all over the world only when GM crops were released into the field. Plant ecologists, microbiologists and population geneticists carried out experiments aimed at evaluating the environmental impact of GM crops. The most significant findings concern: the spread of transgenes through GM pollen diffusion and its environmental impact after hybridisation with closely related wild species or subspecies; horizontal gene transfer from transgenic plants to soil microbes; the impact of insecticide proteins released into the soil by transformed plants on non-target microbial soil communities. Recent developments in genetic engineering produced a technology, dubbed "Terminator", which protects patented genes introduced in transgenic plants by killing the seeds in the second generation. This genetic construct, which interferes so heavily with fundamental life processes, is considered dangerous and should be ex-ante evaluated taking into account the data on "unexpected events", as here discussed, instead of relying on the "safe until proven otherwise" claim. Awareness that scientists, biotechnologists and genetic engineers cannot answer the fundamental question "how likely is that transgenes will be transferred from cultivated plants into the natural environment?" should foster long-term studies on the ecological risks and benefits of transgenic crops.

  6. Leaf morphology and ultrastructure responses to elevated O3 in transgenic Bt (cry1Ab/cry1Ac rice and conventional rice under fully open-air field conditions.

    Directory of Open Access Journals (Sweden)

    Chunyan Li

    Full Text Available BACKGROUND: Elevated tropospheric ozone severely affects not only yield but also the morphology, structure and physiological functions of plants. Because of concerns regarding the potential environmental risk of transgenic crops, it is important to monitor changes in transgenic insect-resistant rice under the projected high tropospheric ozone before its commercial release. METHODOLOGY/PRINCIPAL FINDINGS: Using a free-air concentration enrichment (FACE system, we investigated the changes in leaf morphology and leaf ultrastructure of two rice varieties grown in plastic pots, transgenic Bt Shanyou 63 (Bt-SY63, carrying a fusion gene of cry1Ab and cry1Ac and its non-transgenic counterpart (SY63, in elevated O3 (E-O3 versus ambient O3 (A-O3 after 64-DAS (Days after seeding, 85-DAS and 102-DAS. Our results indicated that E-O3 had no significant effects on leaf length, leaf width, leaf area, stomatal length and stomatal density for both Bt-SY63 and SY63. E-O3 increased the leaf thickness of Bt-SY63, but decreased that of SY63. O3 stress caused early swelling of the thylakoids of chloroplasts, a significant increase in the proportion of total plastoglobule area in the entire cell area (PCAP and a significant decrease in the proportion of total starch grain area in the entire cell area (SCAP, suggesting that E-O3 accelerated the leaf senescence of the two rice genotypes. Compared with SY63, E-O3 caused early swelling of the thylakoids of chloroplasts and more substantial breakdown of chloroplasts in Bt-SY63. CONCLUSIONS/SIGNIFICANCE: Our results suggest that the incorporation of cry1Ab/Ac into SY63 could induce unintentional changes in some parts of plant morphology and that O3 stress results in greater leaf damage to Bt-SY63 than to SY63, with the former coupled with higher O3 sensitivity in CCAP (the proportions of total chloroplast area in the entire cell area, PCAP and SCAP. This study provides valuable baseline information for the prospective

  7. Evaluating genetic containment strategies for transgenic plants.

    Science.gov (United States)

    Lee, David; Natesan, Ellen

    2006-03-01

    One of the primary concerns about genetically engineered crop plants is that they will hybridize with wild relatives, permitting the transgene to escape into the environment. The likelihood that a transgene will spread in the environment depends on its potential fitness impact. The fitness conferred by various transgenes to crop and/or wild-type hybrids has been evaluated in several species. Different strategies have been developed for reducing the probability and impact of gene flow, including physical separation from wild relatives and genetic engineering. Mathematical models and empirical experimental evidence suggest that genetic approaches have the potential to effectively prevent transgenes from incorporating into wild relatives and becoming established in wild populations that are not reproductively isolated from genetically engineered crops.

  8. Reduced fitness of Daphnia magna fed a Bt-transgenic maize variety.

    Science.gov (United States)

    Bøhn, Thomas; Primicerio, Raul; Hessen, Dag O; Traavik, Terje

    2008-11-01

    Genetically modified (GM) maize expressing the Bt-toxin Cry1Ab (Bt-maize) was tested for effects on survival, growth, and reproduction of the water flea Daphnia magna, a crustacean arthropod commonly used as a model organism in ecotoxicological studies. In three repeated experiments, D. magna were fed 100% ground maize in suspension, using either GM or isogenic unmodified (UM) maize. D. magna fed GM-maize showed a significantly reduced fitness performance: The mortality was higher, a lower proportion of females reached sexual maturation, and the overall egg production was lower compared to D. magna fed UM isogenic maize. We conclude that the tested variety of Bt-maize and its UM counterpart do not have the same quality as food sources for this widely used model organism. The combination of a reduced fitness performance combined with earlier onset of reproduction of D. magna fed Bt-maize indicates a toxic effect rather than a lower nutritional value of the GM-maize.

  9. Transgenic plants with increased calcium stores

    Science.gov (United States)

    Wyatt, Sarah (Inventor); Tsou, Pei-Lan (Inventor); Robertson, Dominique (Inventor); Boss, Wendy (Inventor)

    2004-01-01

    The present invention provides transgenic plants over-expressing a transgene encoding a calcium-binding protein or peptide (CaBP). Preferably, the CaBP is a calcium storage protein and over-expression thereof does not have undue adverse effects on calcium homeostasis or biochemical pathways that are regulated by calcium. In preferred embodiments, the CaBP is calreticulin (CRT) or calsequestrin. In more preferred embodiments, the CaBP is the C-domain of CRT, a fragment of the C-domain, or multimers of the foregoing. In other preferred embodiments, the CaBP is localized to the endoplasmic reticulum by operatively associating the transgene encoding the CaBP with an endoplasmic reticulum localization peptide. Alternatively, the CaBP is targeted to any other sub-cellular compartment that permits the calcium to be stored in a form that is biologically available to the plant. Also provided are methods of producing plants with desirable phenotypic traits by transformation of the plant with a transgene encoding a CaBP. Such phenotypic traits include increased calcium storage, enhanced resistance to calcium-limiting conditions, enhanced growth and viability, increased disease and stress resistance, enhanced flower and fruit production, reduced senescence, and a decreased need for fertilizer production. Further provided are plants with enhanced nutritional value as human food or animal feed.

  10. Histopathology of the larval midgut of Helicoverpa armigera (Hübner fed on Bacillus thuringiensis crystals and Bt-tomato plants

    Directory of Open Access Journals (Sweden)

    N.M. Abd El-Ghany

    2015-12-01

    Full Text Available The histopathological effects of the spore-crystal complex of indigenous Bacillus thuringiensis (Bt isolate, as well as Cry 2Ab gene expressed in transgenic tomato plants on the midgut of 4th instar larva of Helicoverpa armigera (Hübner (Lepidoptera: Noctuidea has been investigated using the transmission electron microscope (TEM. Remarkable ultrastructural changes were observed in the columnar and goblet cells of the larval midgut after feeding on either transgenic tomato leaves, or spore-crystal complex of Bt. The effects observed included breakdown of microvilli of epithelial cells, increase in the electron density of the cytoplasm and vacuolation associated with different sizes of lysosomes; interruption of the goblet cells and distorted goblet cavities which lost their cytoplasmic projections; destruction of the mitochondria which lost their cristae; degeneration of the endoplasmic reticulum; collapse of the nucleus associated with rupture of nuclear envelope and clumped chromatin. Feeding the larvae on transgenic Bt-tomato plants caused in addition to the aforementioned changes severe vacuolation and degeneration of the nucleus in both columnar and goblet cells and the nuclear membrane was broken into electron dense ring spheres.

  11. First-Generation Transgenic Plants and Statistics

    NARCIS (Netherlands)

    Nap, Jan-Peter; Keizer, Paul; Jansen, Ritsert

    1993-01-01

    The statistical analyses of populations of first-generation transgenic plants are commonly based on mean and variance and generally require a test of normality. Since in many cases the assumptions of normality are not met, analyses can result in erroneous conclusions. Transformation of data to

  12. Strategies for antiviral resistance in transgenic plants

    NARCIS (Netherlands)

    Prins, M.W.; Laimer, M.; Noris, E.; Schubert, J.; Wassenegger, M.; Tepfer, M.

    2008-01-01

    Genetic engineering offers a means of incorporating new virus resistance traits into existing desirable plant cultivars. The initial attempts to create transgenes conferring virus resistance were based on the pathogen-derived resistance concept. The expression of the viral coat protein gene in

  13. Transgenic sorghum plants via microprojectile bombardment.

    Science.gov (United States)

    Casas, A M; Kononowicz, A K; Zehr, U B; Tomes, D T; Axtell, J D; Butler, L G; Bressan, R A; Hasegawa, P M

    1993-12-01

    Transgenic sorghum plants have been obtained after microprojectile bombardment of immature zygotic embryos of a drought-resistant sorghum cultivar, P898012. DNA delivery parameters were optimized based on transient expression of R and C1 maize anthocyanin regulatory elements in scutellar cells. The protocol for obtaining transgenic plants consists of the delivery of the bar gene to immature zygotic embryos and the imposition of bialaphos selection pressure at various stages during culture, from induction of somatic embryogenesis to rooting of regenerated plantlets. One in about every 350 embryos produced embryogenic tissues that survived bialaphos treatment; six transformed callus lines were obtained from three of the eight sorghum cultivars used in this research. Transgenic (T0) plants were obtained from cultivar P898012 (two independent transformation events). The presence of the bar and uidA genes in the T0 plants was confirmed by Southern blot analysis of genomic DNA. Phosphinothricin acetyltransferase activity was detected in extracts of the T0 plants. These plants were resistant to local application of the herbicide Ignite/Basta, and the resistance was inherited in T1 plants as a single dominant locus.

  14. A simple and rapid method for determining transgenic cotton plants.

    Science.gov (United States)

    Zhang, Baohong; Wang, Hongmei; Liu, Fang; Wang, Qinglian

    2013-01-01

    Determining transgenic events is a critical step for obtaining transgenic plants as well as the later stage of application. Traditional methods, such as Northern blotting and qRT-PCR, for determining transgenic events either require radioactively labeled substrates, expensive instruments, or long-time commitments, which result in lab and time-consuming as well as expensive costs. These methods also require destroying the transgenic events. In this chapter, we present a simple and rapid method for determining transgenic cotton plants in both laboratory and field conditions. This method is based on the sensitivity of transgenic and non-transgenic plants to a specific chemical, such as antibiotics or herbicides. This method will facilitate the screening of transgenic events, save time, reduce cost, and speed up the application of transgenic technology on cotton breeding and production. More important, this is a nondestructive bioassay method; the transgenic plants can be transferred into greenhouse or field for the later study after the detection process.

  15. Phytoremediation of selenium using transgenic plants.

    Science.gov (United States)

    Pilon-Smits, Elizabeth A H; LeDuc, Danika L

    2009-04-01

    Selenium (Se) is a micronutrient for many organisms but also toxic at higher concentrations. Both selenium deficiency and toxicity are serious problems worldwide. Owing to the similarity of selenium to sulfur, plants readily take up and assimilate selenate via sulfur transporters and enzymes and can even volatilize selenium. Selenium accumulating or volatilizing plants may be used for phytoremediation of selenium pollution and as fortified foods. Several transgenic approaches have been used successfully to further enhance plant selenium accumulation, tolerance, and volatilization: upregulation of genes involved in sulfur/selenium assimilation and volatilization, methylation of selenocysteine, and conversion of selenocysteine to elemental Se. Lab and field trials with different transgenic plants have yielded promising results, showing up to ninefold higher levels of selenium accumulation and up to threefold faster volatilization rates.

  16. Transgenic Bt rice lines producing Cry1Ac, Cry2Aa or Cry1Ca have no detrimental effects on Brown Planthopper and Pond Wolf Spider.

    Science.gov (United States)

    Niu, Lin; Mannakkara, Amani; Qiu, Lin; Wang, Xiaoping; Hua, Hongxia; Lei, Chaoliang; Jurat-Fuentes, Juan Luis; Ma, Weihua

    2017-05-16

    Transgenic rice expressing cry genes from the bacterium Bacillus thuringiensis (Bt rice) is highly resistant to lepidopteran pests. The brown planthopper (BPH, Nilaparvata lugens) is the main non-target sap-sucking insect pest of Bt transgenic rice. The pond wolf spider (PWS, Pardosa pseudoannulata) is one of the most dominant predators of BPH in rice fields. Consequently, the safety evaluation of Bt rice on BPH and PWS should be conducted before commercialization. In the current study, two experiments were performed to assess the potential ecological effects of Bt rice on BPH and PWS: (1) a tritrophic experiment to evaluate the transmission of Cry1Ac, Cry2Aa and Cry1Ca protein in the food chain; and (2) binding assays of Cry1Ac, Cry2Aa and Cry1Ca to midgut brush border membrane proteins from BPH and PWS. Trace amounts of the three Cry proteins were detected in BPH feeding on Bt rice cultivars, but only Cry1Ac and Cry2Aa proteins could be transferred to PWS through feeding on BPH. In vitro binding of biotinylated Cry proteins and competition assays in midgut protein vesicles showed weak binding, and ligand blot analysis confirmed the binding specificity. Thus, we inferred that the tested Bt rice varieties have negligible effects on BPH and PWS.

  17. The impact of common smut(Ustilago maydis) on aflatoxin and fumonisin in transgenic Bt and non-Bt maize (Zea mays)

    Science.gov (United States)

    Corn infected with Ustilago maydis (common smut), produces galls that are valued food in certain cultures, but may be contaminated with mycotoxins. Field studies conducted in Elizabeth, Mississippi used near-isogenic Bt and non-Bt corn hybrids. The levels of aflatoxin and fumonisin were determined ...

  18. An efficient grafting technique for recovery of transgenic cotton plants.

    Science.gov (United States)

    Wang, Min; Wang, Qinglian; Zhang, Baohong

    2013-01-01

    Recovery of transgenic cotton plants from tissue culture condition to greenhouse condition is a critical step for improving cotton through genetic engineering. Traditional methods always cause low survival rate of transplanted plants. In 1998, we developed an efficient grafting technique for recovery of transgenic cotton plants, which significantly increased the survival rate of the transplanting regeneration plants. In this chapter, we present a detailed protocol for grafting transgenic cotton plants obtaining somatic embryogenesis.

  19. Inhibition of Helicoverpa zea (Lepidoptera: Noctuidae) Growth by Transgenic Corn Expressing Bt Toxins and Development of Resistance to Cry1Ab.

    Science.gov (United States)

    Reisig, Dominic D; Reay-Jones, Francis P F

    2015-08-01

    Transgenic corn, Zea mays L., that expresses the Bacillus thuringiensis (Bt) toxin Cry1Ab is only moderately toxic to Helicoverpa zea (Boddie) and has been planted commercially since 1996. Growth and development of H. zea was monitored to determine potential changes in susceptibility to this toxin over time. Small plots of corn hybrids expressing Cry1F, Cry1F × Cry1Ab, Cry1Ab × Cry3Bb1, Cry1A.105 × Cry2Ab2 × Cry3Bb1, Cry1A.105 × Cry2Ab2, and Vip3Aa20 × Cry1Ab × mCry3A were planted in both 2012 and 2013 inNorth and South Carolina with paired non-Bt hybrids from the same genetic background. H. zea larvae were sampled on three time periods from ears and the following factors were measured: kernel area injured (cm(2)) by H. zea larvae, larval number per ear, larval weight, larval length, and larval head width. Pupae were sampled on a single time period and the following factors recorded: number per ear, weight, time to eclosion, and the number that eclosed. There was no reduction in larval weight, number of insect entering the pupal stadium, pupal weight, time to eclosion, and number of pupae able to successfully eclose to adulthood in the hybrid expressing Cry1Ab compared with a non-Bt paired hybrid. As Cry1Ab affected these in 1996, H. zea may be developing resistance to Cry1Ab in corn, although these results are not comprehensive, given the limited sampling period, size, and geography. We also found that the negative impacts on larval growth and development were greater in corn hybrids with pyramided traits compared with single traits. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Fungi of the Fusarium genus in the grains of conventional hybrids and transgenic Bt-hybrids of maize (Zea mays L. in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Martin Kmoch

    2012-01-01

    Full Text Available Fungi of the Fusarium genus, the agent of ear rot in maize, not only causes decrease in yields but also negatively affects grain quality and, in relation to mycotoxins production, the health of humans and animals. This study focuses on determining the species range of Fusarium fungi in naturally infected stands of conventional hybrids and transgenic Bt-hybrids of maize in the Czech Republic during 2008 and 2009. Individual species of the Fusarium genus were determined on the basis of morphological characteristics and using polymerase chain reaction. Ten mycotoxigenic species were identified in hybrid maize grains: F. subglutinans (40.4%, F. graminearum (19.8%, F. verticillioides (18.2%, F. poae (9.3%, F. proliferatum (4.0%, F. avenaceum (3.8%, F. oxysporum (1.7%, F. sporotrichioides (1.3%, F. sambucinum (1.3% and F. culmorum (0.2%. The species F. subglutinans, F. graminearum and F. verticillioides were dominant in both years. The frequency of individual Fusarium species did not significantly differ between conventional and transgenic Bt-hybrids. Differences in species representation were determined between individual years and sites. The hypothesized markedly lower infection of individual Bt-hybrids with fungi of the Fusarium genus was not statistically significant, although most Bt-hybrids did demonstrate lower infection without that being statistically significant. The average level of infection by the Fusarium genus in 2008 was 13.2% for grains of conventional hybrids and 6.6% for Bt-hybrids (50% lower. In 2009, the average infection level was 13.6% for conventional hybrids and 12.6% for Bt-hybrids (7.4% lower. The average infection level for grains of Bt-hybrids by the species F. subglutinans, F. graminearum and F. proliferatum was lower than that for grains of conventional hybrids in both years.

  1. Expression of Cry1Ab protein in a marker-free transgenic Bt rice line and its efficacy in controlling a target pest, Chilo suppressalis (Lepidoptera: Crambidae).

    Science.gov (United States)

    Wang, Yanan; Zhang, Lei; Li, Yunhe; Liu, Yanmin; Han, Lanzhi; Zhu, Zhen; Wang, Feng; Peng, Yufa

    2014-04-01

    A marker-free Bt transgenic rice line, mfb-MH86, was recently developed in China, which contains a cry1Ab gene driven by a ubiquitin promoter. This Bt gene confers resistance to a range of lepidopteran species, including the striped stem borer, Chilo suppressalis (Walker). The expression of Cry1Ab protein in mfb-MH86 leaves, stems and leaf sheaths (hereinafter referred to as stems), and roots was evaluated throughout the rice-growing season using an enzyme-linked immunosorbent assay. In addition, mfb-MH86 resistance to C. suppressalis, a major pest of rice, was evaluated in a laboratory bioassay with field-collected rice stems. Cry1Ab protein levels of mfb-MH86 were highest in leaves (9.71-34.09 μg/g dry weight [DW]), intermediate in stems (7.66-18.51 μg/g DW), and lowest in roots (1.95-13.40 μg/g DW). In all tissues, Cry1Ab levels in mfb-MH86 were higher in seedling and tillering stages than in subsequent growth stages. In the laboratory bioassay, mortality of C. suppressalis after 6 d of feeding on mfb-MH86 stems was 100% throughout the rice-growing season; mortality of C. suppressalis when feeding on stems of the nontransformed isoline, MH86, ranged from 15.0 to 38.3%. The results indicate that Cry1Ab protein levels in mfb-MH86 stems are sufficient to protect plants against C. suppressalis throughout the rice-growing season. Although our results are promising, further comprehensive evaluations of mfb-MH86, including field surveys, will be needed before commercial use.

  2. Effects of Bt-maize material on the life cycle of the land snail Cantareus aspersus

    DEFF Research Database (Denmark)

    Kramarz, Paulina; de Vaufleury, Annette; Gimbert, Frédéric

    2009-01-01

    Insect resistant Bt-maize (MON 810) expresses active Cry1Ab endotoxin derived from Bacillus thuringiensis (Bt). Snails constitute non-target soil species potentially exposed to Bt-toxin through consumption of plant material and soil in fields where transgenic plants have been grown. We studied...

  3. Transgenic plants as factories for biopharmaceuticals.

    Science.gov (United States)

    Giddings, G; Allison, G; Brooks, D; Carter, A

    2000-11-01

    Plants have considerable potential for the production of biopharmaceutical proteins and peptides because they are easily transformed and provide a cheap source of protein. Several biotechnology companies are now actively developing, field testing, and patenting plant expression systems, while clinical trials are proceeding on the first biopharmaceuticals derived from them. One transgenic plant-derived biopharmaceutical, hirudin, is now being commercially produced in Canada for the first time. Product purification is potentially an expensive process, and various methods are currently being developed to overcome this problem, including oleosin-fusion technology, which allows extraction with oil bodies. In some cases, delivery of a biopharmaceutical product by direct ingestion of the modified plant potentially removes the need for purification. Such biopharmaceuticals and edible vaccines can be stored and distributed as seeds, tubers, or fruits, making immunization programs in developing countries cheaper and potentially easier to administer. Some of the most expensive biopharmaceuticals of restricted availability, such as glucocerebrosidase, could become much cheaper and more plentiful through production in transgenic plants.

  4. Transgenic plants in the biopharmaceutical market.

    Science.gov (United States)

    Twyman, Richard M; Schillberg, Stefan; Fischer, Rainer

    2005-02-01

    Many of our 'small-molecule-drugs' are natural products from plants, or are synthetic compounds based on molecules found naturally in plants. However, the vast majority of the protein therapeutics (or biopharmaceuticals) we use are from animal or human sources, and are produced commercially in microbial or mammalian bioreactor systems. Over the last few years, it has become clear that plants have great potential for the production of human proteins and other protein-based therapeutic entities. Plants offer the prospect of inexpensive biopharmaceutical production without sacrificing product quality or safety, and following the success of several plant-derived technical proteins, the first therapeutic products are now approaching the market. In this review, the different plant-based production systems are discussed and the merits of transgenic plants are evaluated compared with other platforms. A detailed discussion is provided of the development issues that remain to be addressed before plants become an acceptable mainstream production technology. The many different proteins that have already been produced using plants are described, and a sketch of the current market and the activities of the key players is provided. Despite the currently unclear regulatory framework and general industry inertia, the benefits of plant-derived pharmaceuticals are now bringing the prospect of inexpensive veterinary and human medicines closer than ever before.

  5. Development of transgenic CryIA(c) + GNA cotton plants via pollen tube pathway method confers resistance to Helicoverpa armigera and Aphis gossypii Glover.

    Science.gov (United States)

    Liu, Zhi; Zhu, Zhen; Zhang, Tianzhen

    2013-01-01

    Elite cotton cultivar Sumian16 was transformed with p7RPSBK-mGNA-NPTII containing Bt (CryIA(c)), Galanthus nivalis agglutinin (GNA) resistance genes and selectable marker NptII gene via the pollen tube pathway method and two fertile transgenic Bt + GNA plants were obtained in the present study. The integration and expression of the Bt and GNA genes were confirmed by molecular biology techniques and insect bioassays. Insect bioassays showed that the transformed plants were highly toxic to bollworm larvae as well as obviously retarding development of aphid populations. PCR analyses and identification of resistance to Kanamycin and bollworm showed that the resistance to bollworm for the two transgenic plants was dominantly inherited in a Mendelian manner and the two resistance genes and selectable marker co-segregated from primary transformed parents to the first self-fertilized progeny plants.

  6. A perspective on management of Helicoverpa armigera: transgenic Bt cotton, IPM, and landscapes.

    Science.gov (United States)

    Downes, Sharon; Kriticos, Darren; Parry, Hazel; Paull, Cate; Schellhorn, Nancy; Zalucki, Myron P

    2017-03-01

    Helicoverpa armigera is a major pest of agriculture, horticulture and floriculture throughout the Old World and recently invaded parts of the New World. We overview of the evolution in thinking about the application of area-wide approaches to assist with its control by the Australian Cotton Industry to highlight important lessons and future challenges to achieving the same in the New World. An over-reliance of broad-spectrum insecticides led to Helicoverpa spp. in Australian cotton rapidly became resistant to DDT, synthetic pyrethroids, organophosphates, carbamates and endosulfan. Voluntary strategies were developed to slow the development of insecticide resistance, which included rotating chemistries and basing spray decisions on thresholds. Despite adoption of these practices, insecticide resistance continued to develop until the introduction of genetically modified cotton provided a platform for augmenting Integrated Pest Management in the Australian cotton industry. Compliance with mandatory resistance management plans for Bt cotton necessitated a shift from pest control at the level of individual fields or farms towards a coordinated area-wide landscape approach. Our take-home message for control of H. armigera is that resistance management is essential in genetically modified crops and must be season long and area-wide to be effective. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. Tritrophic choice experiments with Bt plants, the diamondback moth (Plutella xylostella) and the parasitoid Cotesia plutellae

    NARCIS (Netherlands)

    Schuler, T.H.; Potting, R.P.J.; Denholm, I.; Clark, S.J.; Clark, A.J.; Stewart, C.N.; Poppy, G.M.

    2003-01-01

    Parasitoids are important natural enemies of many pest species and are used extensively in biological and integrated control programmes. Crop plants transformed to express toxin genes derived from Bacillus thuringiensis (Bt) provide high levels of resistance to certain pest species, which is likely

  8. Increased survival of western corn rootworm on transgenic corn within three generations of on-plant greenhouse selection.

    Science.gov (United States)

    Meihls, Lisa N; Higdon, Matthew L; Siegfried, Blair D; Miller, Nicholas J; Sappington, Thomas W; Ellersieck, Mark R; Spencer, Terence A; Hibbard, Bruce E

    2008-12-09

    To delay evolution of insect resistance to transgenic crops producing Bacillus thuringiensis (Bt) toxins, nearby "refuges" of host plants not producing Bt toxins are required in many regions. Such refuges are expected to be most effective in slowing resistance when the toxin concentration in Bt crops is high enough to kill all or nearly all insects heterozygous for resistance. However, Bt corn, Zea mays, introduced recently does not meet this "high-dose" criterion for control of western corn rootworm (WCR), Diabrotica virgifera virgifera. A greenhouse method of rearing WCR on transgenic corn expressing the Cry3Bb1 protein was used in which approximately 25% of previously unexposed larvae survived relative to isoline survival (compared to 1-4% in the field). After three generations of full larval rearing on Bt corn (Constant-exposure colony), WCR larval survival was equivalent on Bt corn and isoline corn in greenhouse trials, and the LC(50) was 22-fold greater for the Constant-exposure colony than for the Control colony in diet bioassays with Cry3Bb1 protein on artificial diet. After six generations of greenhouse selection, the ratio of larval recovery on Bt corn to isoline corn in the field was 11.7-fold greater for the Constant-exposure colony than the Control colony. Removal from selection for six generations did not decrease survival on Bt corn in the greenhouse. The results suggest that rapid response to selection is possible in the absence of mating with unexposed beetles, emphasizing the importance of effective refuges for resistance management.

  9. Effects of feeding Bt maize to sows during gestation and lactation on maternal and offspring immunity and fate of transgenic material.

    Directory of Open Access Journals (Sweden)

    Stefan G Buzoianu

    Full Text Available BACKGROUND: We aimed to determine the effect of feeding transgenic maize to sows during gestation and lactation on maternal and offspring immunity and to assess the fate of transgenic material. METHODOLOGY/PRINCIPAL FINDINGS: On the day of insemination, sows were assigned to one of two treatments (n = 12/treatment; 1 non-Bt control maize diet or 2 Bt-MON810 maize diet, which were fed for ~143 days throughout gestation and lactation. Immune function was assessed by leukocyte phenotyping, haematology and Cry1Ab-specific antibody presence in blood on days 0, 28 and 110 of gestation and at the end of lactation. Peripheral-blood mononuclear cell cytokine production was investigated on days 28 and 110 of gestation. Haematological analysis was performed on offspring at birth (n = 12/treatment. Presence of the cry1Ab transgene was assessed in sows' blood and faeces on day 110 of gestation and in blood and tissues of offspring at birth. Cry1Ab protein presence was assessed in sows' blood during gestation and lactation and in tissues of offspring at birth. Blood monocyte count and percentage were higher (P<0.05, while granulocyte percentage was lower (P<0.05 in Bt maize-fed sows on day 110 of gestation. Leukocyte count and granulocyte count and percentage were lower (P<0.05, while lymphocyte percentage was higher (P<0.05 in offspring of Bt maize-fed sows. Bt maize-fed sows had a lower percentage of monocytes on day 28 of lactation and of CD4(+CD8(+ lymphocytes on day 110 of gestation, day 28 of lactation and overall (P<0.05. Cytokine production was similar between treatments. Transgenic material or Cry1Ab-specific antibodies were not detected in sows or offspring. CONCLUSIONS/SIGNIFICANCE: Treatment differences observed following feeding of Bt maize to sows did not indicate inflammation or allergy and are unlikely to be of major importance. These results provide additional data for Bt maize safety assessment.

  10. Effects of feeding Bt maize to sows during gestation and lactation on maternal and offspring immunity and fate of transgenic material.

    Science.gov (United States)

    Buzoianu, Stefan G; Walsh, Maria C; Rea, Mary C; O'Donovan, Orla; Gelencsér, Eva; Ujhelyi, Gabriella; Szabó, Erika; Nagy, Andras; Ross, R Paul; Gardiner, Gillian E; Lawlor, Peadar G

    2012-01-01

    We aimed to determine the effect of feeding transgenic maize to sows during gestation and lactation on maternal and offspring immunity and to assess the fate of transgenic material. On the day of insemination, sows were assigned to one of two treatments (n = 12/treatment); 1) non-Bt control maize diet or 2) Bt-MON810 maize diet, which were fed for ~143 days throughout gestation and lactation. Immune function was assessed by leukocyte phenotyping, haematology and Cry1Ab-specific antibody presence in blood on days 0, 28 and 110 of gestation and at the end of lactation. Peripheral-blood mononuclear cell cytokine production was investigated on days 28 and 110 of gestation. Haematological analysis was performed on offspring at birth (n = 12/treatment). Presence of the cry1Ab transgene was assessed in sows' blood and faeces on day 110 of gestation and in blood and tissues of offspring at birth. Cry1Ab protein presence was assessed in sows' blood during gestation and lactation and in tissues of offspring at birth. Blood monocyte count and percentage were higher (PBt maize-fed sows on day 110 of gestation. Leukocyte count and granulocyte count and percentage were lower (PBt maize-fed sows. Bt maize-fed sows had a lower percentage of monocytes on day 28 of lactation and of CD4(+)CD8(+) lymphocytes on day 110 of gestation, day 28 of lactation and overall (Pspecific antibodies were not detected in sows or offspring. Treatment differences observed following feeding of Bt maize to sows did not indicate inflammation or allergy and are unlikely to be of major importance. These results provide additional data for Bt maize safety assessment.

  11. Efficient genetic transformation of okra (Abelmoschus esculentus (L.) Moench) and generation of insect-resistant transgenic plants expressing the cry1Ac gene.

    Science.gov (United States)

    Narendran, M; Deole, Satish G; Harkude, Satish; Shirale, Dattatray; Nanote, Asaram; Bihani, Pankaj; Parimi, Srinivas; Char, Bharat R; Zehr, Usha B

    2013-08-01

    Agrobacterium -mediated transformation system for okra using embryos was devised and the transgenic Bt plants showed resistance to the target pest, okra shoot, and fruit borer ( Earias vittella ). Okra is an important vegetable crop and progress in genetic improvement via genetic transformation has been impeded by its recalcitrant nature. In this paper, we describe a procedure using embryo explants for Agrobacterium-mediated transformation and tissue culture-based plant regeneration for efficient genetic transformation of okra. Twenty-one transgenic okra lines expressing the Bacillus thuringiensis gene cry1Ac were generated from five transformation experiments. Molecular analysis (PCR and Southern) confirmed the presence of the transgene and double-antibody sandwich ELISA analysis revealed Cry1Ac protein expression in the transgenic plants. All 21 transgenic plants were phenotypically normal and fertile. T1 generation plants from these lines were used in segregation analysis of the transgene. Ten transgenic lines were selected randomly for Southern hybridization and the results confirmed the presence of transgene integration into the genome. Normal Mendelian inheritance (3:1) of cry1Ac gene was observed in 12 lines out of the 21 T0 lines. We selected 11 transgenic lines segregating in a 3:1 ratio for the presence of one transgene for insect bioassays using larvae of fruit and shoot borer (Earias vittella). Fruit from seven transgenic lines caused 100 % larval mortality. We demonstrate an efficient transformation system for okra which will accelerate the development of transgenic okra with novel agronomically useful traits.

  12. Effects of 90-day feeding of transgenic Bt rice TT51 on the reproductive system in male rats.

    Science.gov (United States)

    Wang, Er Hui; Yu, Zhou; Hu, Jing; Xu, Hai Bin

    2013-12-01

    Rice is a staple food crop; however, the threat of pests leads to a serious decline in its output and quality. The CryAb/CryAc gene, encodes a synthetic fusion Bacillus thuringiensis (Bt) crystal protein, was introduced into rice MingHui63 to produce insect-resistant rice TT51. This study was undertaken to investigate potential unintended effects of TT51 on the reproductive system in male rats. Male rats were treated with diets containing 60% of either TT51 or MingHui63 by weight, nutritionally balanced to an AIN93G diet, for 90days. An additional negative control group of rats were fed with a rice-based AIN93G diet. Body weights, food intake, hematology, serum chemistry, serum hormone levels, sperm parameters and relative organ/body weights were measured, and gross as well as microscopic pathology were examined. No diet-related significant differences in the values of response variables were observed between rats that were fed with diet containing transgenic TT51, MingHui63 and the control in this 90-day feeding study. In addition, necropsy and histopathology examination indicated no treatment-related changes. The results from the present study indicated that TT51 does not appear to exert any effect on the reproductive system in male rats compared with MingHui63 or the control. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Efficient generation of marker-free transgenic rice plants using an improved transposon-mediated transgene reintegration strategy

    National Research Council Canada - National Science Library

    Gao, Xiaoqing; Zhou, Jie; Li, Jun; Zou, Xiaowei; Zhao, Jianhua; Li, Qingliang; Xia, Ran; Yang, Ruifang; Wang, Dekai; Zuo, Zhaoxue; Tu, Jumin; Tao, Yuezhi; Chen, Xiaoyun; Xie, Qi; Zhu, Zengrong; Qu, Shaohong

    2015-01-01

    Marker-free transgenic plants can be developed through transposon-mediated transgene reintegration, which allows intact transgene insertion with defined boundaries and requires only a few primary transformants...

  14. The halo effect: suppression of pink bollworm on non-Bt cotton by Bt cotton in China.

    Directory of Open Access Journals (Sweden)

    Peng Wan

    Full Text Available In some previously reported cases, transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce Bt toxins. Here we used 16 years of field data to determine if Bt cotton caused this "halo effect" against pink bollworm (Pectinophora gossypiella in six provinces of the Yangtze River Valley of China. In this region, the percentage of cotton hectares planted with Bt cotton increased from 9% in 2000 to 94% in 2009 and 2010. We found that Bt cotton significantly decreased the population density of pink bollworm on non-Bt cotton, with net decreases of 91% for eggs and 95% for larvae on non-Bt cotton after 11 years of Bt cotton use. Insecticide sprays targeting pink bollworm and cotton bollworm (Helicoverpa armigera decreased by 69%. Previously reported evidence of the early stages of evolution of pink bollworm resistance to Bt cotton in China has raised concerns that if unchecked, such resistance could eventually diminish or eliminate the benefits of Bt cotton. The results reported here suggest that it might be possible to find a percentage of Bt cotton lower than the current level that causes sufficient regional pest suppression and reduces the risk of resistance.

  15. Fate of Transgenic DNA from Orally Administered Bt MON810 Maize and Effects on Immune Response and Growth in Pigs

    Science.gov (United States)

    Walsh, Maria C.; Buzoianu, Stefan G.; Gardiner, Gillian E.; Rea, Mary C.; Gelencsér, Eva; Jánosi, Anna; Epstein, Michelle M.; Ross, R. Paul; Lawlor, Peadar G.

    2011-01-01

    We assessed the effect of short-term feeding of genetically modified (GM: Bt MON810) maize on immune responses and growth in weanling pigs and determined the fate of the transgenic DNA and protein in-vivo. Pigs were fed a diet containing 38.9% GM or non-GM isogenic parent line maize for 31 days. We observed that IL-12 and IFNγ production from mitogenic stimulated peripheral blood mononuclear cells decreased (PGM maize exposure. While Cry1Ab-specific IgG and IgA were not detected in the plasma of GM maize-fed pigs, the detection of the cry1Ab gene and protein was limited to the gastrointestinal digesta and was not found in the kidneys, liver, spleen, muscle, heart or blood. Feeding GM maize to weanling pigs had no effect on growth performance or body weight. IL-6 and IL-4 production from isolated splenocytes were increased (PGM maize while the proportion of CD4+ T cells in the spleen decreased. In the ileum, the proportion of B cells and macrophages decreased while the proportion of CD4+ T cells increased in GM maize-fed pigs. IL-8 and IL-4 production from isolated intraepithelial and lamina propria lymphocytes were also increased (PGM maize. In conclusion, there was no evidence of cry1Ab gene or protein translocation to the organs and blood of weaning pigs. The growth of pigs was not affected by feeding GM maize. Alterations in immune responses were detected; however, their biologic relevance is questionable. PMID:22132091

  16. Development of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on pollen from Bt-transgenic and conventional maize.

    Science.gov (United States)

    Meissle, Michael; Zünd, Jan; Waldburger, Mario; Romeis, Jörg

    2014-07-31

    Maize (Zea mays) pollen is highly nutritious and can be used by predatory arthropods to supplement or replace a carnivorous diet. We demonstrate that maize pollen can be utilized by larvae of the green lacewing, Chrysoperla carnea (Neuroptera: Chrysopidae) under laboratory conditions. Complete development on maize pollen was not possible, but 25% of neonates reached the third instar. When only one instar was fed with pollen and the other two instars with eggs of Ephestia kuehniella (Lepidoptera: Pyralidae), 58-87% of the larvae reached the pupal stage. The experiments included pollen produced by nine cultivars: three genetically modified (GM) cultivars expressing the Bacillus thuringiensis proteins Cry1Ab or Cry3Bb1, their corresponding non-transformed near-isolines, and three conventional cultivars. Maize cultivars were grown in two batches in a glasshouse. Their pollen differed by up to 59% in total protein content, 25% in C:N ratio, and 14% in grain diameter, but the differences were inconsistent and depended on the batch. Lacewing performance was not affected by maize cultivar. For environmental risk assessment of GM plants, in planta studies must consider the variability among conventional cultivars, individual plants, batches, and environmental conditions when evaluating the ecological significance of differences observed between GM and near-isolines.

  17. Comparison of transgenic plant production for bacterial blight ...

    African Journals Online (AJOL)

    USER

    2010-03-29

    Mar 29, 2010 ... Resistance of transgenic plants against Xanthomonas oryzae pathovar oryzae was evaluated with various ... The tested transgenic plants were resistant to all the indigenous and exotic strains tested due to the broad ...... indica rice with chitinase gene for enhanced sheath blight resistance. Biologia ...

  18. Lactoferrin-derived resistance against plant pathogens in transgenic plants.

    Science.gov (United States)

    Lakshman, Dilip K; Natarajan, Savithiry; Mandal, Sudhamoy; Mitra, Amitava

    2013-12-04

    Lactoferrin (LF) is a ubiquitous cationic iron-binding milk glycoprotein that contributes to nutrition and exerts a broad-spectrum primary defense against bacteria, fungi, protozoa, and viruses in mammals. These qualities make lactoferrin protein and its antimicrobial motifs highly desirable candidates to be incorporated in plants to impart broad-based resistance against plant pathogens or to economically produce them in bulk quantities for pharmaceutical and nutritional purposes. This study introduced bovine LF (BLF) gene into tobacco ( Nicotiana tabacum var. Xanthi), Arabidopsis ( A. thaliana ) and wheat ( Triticum aestivum ) via Agrobacterium -mediated plant transformation. Transgenic plants or detached leaves exhibited high levels of resistance against the damping-off causing fungal pathogen Rhizoctonia solani and the head blight causing fungal pathogen Fusarium graminearum . LF also imparted resistance to tomato plants against a bacterial pathogen, Ralstonia solanacearum . Similarly, other researchers demonstrated expression of LF and LF-mediated high-quality resistance to several other aggressive fungal and bacterial plant pathogens in transgenic plants and against viral pathogens by foliar applications of LF or its derivatives. Taken together, these studies demonstrated the effectiveness of LF for improving crop quality and its biopharming potentials for pharmaceautical and nutritional applications.

  19. Survival and development of a stored-product pest, Sitophilus zeamais (Coleoptera: Curculionidae), and its natural enemy, the parasitoid Lariophagus distinguendus (Hymenoptera. Pteromalidae), on transgenic Bt maize

    DEFF Research Database (Denmark)

    Hansen, Lise S.; Lövei, Gabor L; Székács, András

    2013-01-01

    Background The effect of transgenic maize (Zea mays L.) containing a lepidopteran-specific Bt toxin on a stored-product pest, Sitophilus zeamais Motschulsky, and its parasitoid, Lariophagus distinguendus Förster, was examined in the laboratory to test the impact of transgenic maize on stored...

  20. Transgenic Campanula carpatica plants with reduced ethylene sensitivity.

    Science.gov (United States)

    Sriskandarajah, Sridevy; Mibus, Heiko; Serek, Margrethe

    2007-06-01

    Fertile transgenic Campanula carpatica Jacq. plants with flowers, which had reduced sensitivity to ethylene were obtained by Agrobacterium tumefaciens that mediated transformation. The construct used for transformation contained the etr1-1 gene from Arabidopsis thaliana under control of the flower specific fbp1-promoter from petunia. More than 100 flowering T0 lines were tested for their ethylene sensitivity using 2 microl l(-1) ethylene. The tolerance level to ethylene varied among the lines. While control plants stopped flowering within 3 days of exposure to ethylene, one of the transformed lines flowered for up to 27 days. The presence and the expression pattern of the transgene in various tissues were studied by polymerase chain reaction (PCR) and reverse transcription (RT)-PCR techniques. The expression of etr1-1 was significant in flowers and buds. Transgenic lines did not differ morphologically from control plants. The selected transgenic T0 lines, which were re-established from in vitro cultures showed the same degree of tolerance to exogenous ethylene, confirming the stability of the transgene in in vitro cultures. The rooting ability of the transgenic plants was not affected by the presence of etr1-1. T1 progeny were produced by crossing the transgenic line, which showed the most significant reduction in ethylene sensitivity with a control plant, and the analysis of the T1 plants showed 1:1 segregation in terms of ethylene sensitivity and the presence of the transgene.

  1. screening of new isolates of bt and cloning of their dna amplicons

    African Journals Online (AJOL)

    NEMAPPA

    2012-09-18

    Sep 18, 2012 ... Screening of more number of Bt isolates is relevant for identifying new cry genes from new isolates of Bt. New gene sequences encoding more active toxins could be used for developing better versions of transgenic crop plants. So, the present study was undertaken with the objectives of characterization of ...

  2. Application of Cry1Ab/Ac Bt strip for screening of resistance for ...

    African Journals Online (AJOL)

    ABU ZAYD

    2013-10-02

    Oct 2, 2013 ... segregating cowpea plants and the genetics of the gene was monitored. The Cry1Ab/Ac Bt strip was ... Key words: Bacillus thuriengiensis, Cry1Ab/Ac Bt strips, transgenic cowpea, Maruca vitrata. INTRODUCTION. Cowpea ... opt for cheaper but more toxic alternatives that impact their health (AATF, 2010).

  3. Expression of Bt-Cry3A in transgenic Populus alba × P. glandulosa and its effects on target and non-target pests and the arthropod community.

    Science.gov (United States)

    Zhang, Bingyu; Chen, Min; Zhang, Xiaofen; Luan, Hehui; Tian, Yingchuan; Su, Xiaohua

    2011-06-01

    During the growing seasons of 2006-2008, feeding tests and field studies were conducted in Beijing, China, to investigate the effects of transgenic Bacillus thuringiensis (Bt) poplar (BGA-5) expressing the Cry3A protein (0.0264-0.0326% of the total soluble protein) on target and non-target pests and the arthropod community. The effects of BGA-5 on the target pest Plagiodera versicolora (Coleoptera, Chrysomelidae) and a non-target pest Clostera anachoreta (Lepidoptera, Notodontidae), were assessed under laboratory conditions. Total mortality of P. versicolora larvae fed with BGA-5 leaves was significantly higher than that of the control (P < 0.05). The exuviation index of P. versicolora larvae fed with BGA-5 tended to be higher than that of CK, but it was not significantly different. The pupation rate and eclosion rate of the survived larvae fed with BGA-5 were lower than that of CK, but it was also not significantly different. Additionally, no significant differences were detected in the mortality, exuviations index, pupation rate, or eclosion rate of C. anachoreta fed with leaves of transgenic and non-transgenic poplars. Furthermore, the arthropod communities in the Bt poplar and CK field stands were similar, as indicated by four diversity indices (Berge-Parker index, Shannon-Wiener indices, evenness index, and Simpson's inverted index) and the Bray-Curtis index. Therefore, the Bt-Cry3A poplar decreased damage by the target pest (P. versicolora), had no effects on a non-target pest (C. anachoreta), and generally did not have any significant negative effect on the poplar arthropod community.

  4. Lectin cDNA and transgenic plants derived therefrom

    Science.gov (United States)

    Raikhel, Natasha V.

    1994-01-04

    Transgenic plants containing cDNA encoding Gramineae lectin are described. The plants preferably contain cDNA coding for barley lectin and store the lectin in the leaves. The transgenic plants, particularly the leaves exhibit insecticidal and fungicidal properties. GOVERNMENT RIGHTS This application was funded under Department of Energy Contract DE-AC02-76ER01338. The U.S. Government has certain rights under this application and any patent issuing thereon.

  5. Composite Phaseolus vulgaris plants with transgenic roots as ...

    African Journals Online (AJOL)

    In this paper a system is described to obtain so-called transgenic composite plants from P. vulgaris. These have a transgenic root system, obtained through Agrobacterium rhizogenes transformation of de-rooted seedlings. Their potentials for studies on important processes in the root system will be discussed.

  6. Bioavailability of transgenic microRNAs in genetically modified plants

    Science.gov (United States)

    Transgenic expression of small RNAs is a prevalent approach in agrobiotechnology for the global enhancement of plant foods. Meanwhile, emerging studies have, on the one hand, emphasized the potential of transgenic microRNAs (miRNAs) as novel dietary therapeutics and, on the other, suggested potentia...

  7. Transgenic plants in the social context

    Directory of Open Access Journals (Sweden)

    José M. Machado Rodríguez

    2004-04-01

    Full Text Available The new biotechnologies take part of the daily life. Within their branches is the vegetal transgenesis which has revolutionized agriculture, considering itself the superior level of the Green Revolution. The transfer of genes from a specie to another one, from a kingdom to the other has made possible the acquisition, by the plants, of unusual characters having allowed them to survive in inhospitable surroundings, to renew the resources of the substrate, to resist to diseases and plagues, herbicides, hydric stress, to provide better nutrients and phytomedicines where the “green vaccines” stand out. The speed with which these technologies have been developed has allowed taking the transgenic cultures to million hectares in many countries of the world, and the number grows every year. In spite of an absent of reports of environmental damages, nor of human health or animal, for more than 45 years of these practices with recombinant DNA, a strict control is followed case by case in the liberation of these genetically modified organisms (GMO by the biosecurity, which plays a fundamental role in the prevision of risks towards environment and the society. The public opinion is divided about this subject so controverted. That is why it is necessary that the scientists explain clearly about the reach of the vegetal biotechnologies and get involve in the interchange of impressions. Key words: biotechnologies, biosafety, public perception

  8. Effect of Bt genetic engineering on indirect defense in cotton via a tritrophic interaction.

    Science.gov (United States)

    Moraes, Maria Carolina Blassioli; Laumann, Raul Alberto; Aquino, Michely Ferreira Santos; Paula, Débora Pires; Borges, Miguel

    2011-02-01

    We present a tritrophic analysis of the potential non-intended pleiotropic effects of cry1Ac gene derived from Bacillus thurigiensis (Bt) insertion in cotton (DeltaPine 404 Bt Bollgard® variety) on the emission of herbivore induced volatile compounds and on the attraction of the egg parasitoid Trichogramma pretisoum (Hymenoptera: Trichogrammatidae). Both the herbivore damaged Bt variety and its non-Bt isoline (DeltaPine DP4049 variety) produced volatiles in higher quantity when compared to undamaged plants and significantly attracted the egg parasitoids (T. pretiosum) when compared to undamaged plants. However, Trichogramma pretiosum did not differentiate between the transgenic and nontransgenic varieties, suggesting that the ratios between the compounds released by herbivory damaged -Bt cotton and herbivory damaged-non Bt cotton did not change significantly. Finally, no detrimental effect of the Bt genetic engineering was detected related to the volatile compounds released by Bollgard cotton on the behavior of the natural enemy studied.

  9. Expression of hepatitis B surface antigen in transgenic banana plants.

    Science.gov (United States)

    Kumar, G B Sunil; Ganapathi, T R; Revathi, C J; Srinivas, L; Bapat, V A

    2005-10-01

    Embryogenic cells of bananan cv. Rasthali (AAB) have been transformed with the 's' gene of hepatitis B surface antigen (HBsAg) using Agrobacterium mediated transformation. Four different expression cassettes (pHBS, pHER, pEFEHBS and pEFEHER) were utilized to optimize the expression of HBsAg in banana. The transgenic nature of the plants and expression of the antigen was confirmed by PCR, Southern hybridization and reverse transcription (RT)-PCR. The expression levels of the antigen in the plants grown under in vitro conditions as well as the green house hardened plants were estimated by ELISA for all the four constructs. Maximum expression level of 38 ng/g F.W. of leaves was noted in plants transformed with pEFEHBS grown under in vitro conditions, whereas pHER transformed plants grown in the green house showed the maximum expression level of 19.92 ng/g F.W. of leaves. Higher monoclonal antibody binding of 67.87% of the antigen was observed when it was expressed with a C-terminal ER retention signal. The buoyant density in CsCl of HBsAg derived from transgenic banana leaves was determined and found to be 1.146 g/ml. HBsAg obtained from transgenic banana plants is similar to human serum derived one in buoyant density properties. The transgenic plants were grown up to maturity in the green house and the expression of HBsAg in the fruits was confirmed by RT-PCR. These transgenic plants were multiplied under in vitro using floral apex cultures. Attempts were also made to enhance the expression of HBsAg in the leaves of transgenic banana plants by wounding and/or treatment with plant growth regulators. This is the first report on the expression of HBsAg in transgenic banana fruits.

  10. A seed mixture increases dominance of resistance to Bt cotton in Helicoverpa zea.

    Science.gov (United States)

    Brévault, Thierry; Tabashnik, Bruce E; Carrière, Yves

    2015-05-07

    Widely grown transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) can benefit agriculture, but adaptation by pests threatens their continued success. Refuges of host plants that do not make Bt toxins can promote survival of susceptible insects and delay evolution of resistance, particularly if resistance is inherited as a recessive trait. However, data have been lacking to compare the dominance of resistance when Bt and non-Bt seeds are planted in random mixtures versus separate blocks. Here we report results from greenhouse experiments with transgenic cotton producing Bt toxin Cry1Ac and the bollworm, Helicoverpa zea, showing that the dominance of resistance was significantly higher in a seed mixture relative to a block of Bt cotton. The proportion of larvae on non-Bt cotton plants in the seed mixture was also significantly higher than expected under the null hypothesis of random distribution. In simulations based on observed survival, resistance evolved 2- to 4.5-fold faster in the seed mixture relative to separate blocks of Bt and non-Bt cotton. These findings support previous modelling results indicating that block refuges may be more effective than seed mixtures for delaying resistance in pests with mobile larvae and inherently low susceptibility to the toxins in Bt crops.

  11. Broad virus resistance in transgenic plants

    NARCIS (Netherlands)

    Prins, M.W.

    2003-01-01

    Viruses are significant threats to agricultural crops worldwide and the limited sources of natural resistance warrant the development of novel resistance sources. Several methods of transgenic protection have been successfully applied, including protein- and RNA-mediated approaches. Increased

  12. Galactose-extended glycans of antibodies produced by transgenic plants

    NARCIS (Netherlands)

    Bakker, H.; Bardor, M.; Molthoff, J.W.; Gomord, V.; Elbers, I.; Stevens, L.H.; Jordi, W.; Lommen, A.; Faye, L.; Lerouge, P.; Bosch, D.

    2001-01-01

    Plant-specific N-glycosylation can represent an important limitation for the use of recombinant glycoproteins of mammalian origin produced by transgenic plants. Comparison of plant and mammalian N-glycan biosynthesis indicates that β1,4-galactosyltransferase is the most important enzyme that is

  13. High-efficiency Agrobacterium-mediated transformation of chickpea (Cicer arietinum L.) and regeneration of insect-resistant transgenic plants.

    Science.gov (United States)

    Mehrotra, Meenakshi; Sanyal, Indraneel; Amla, D V

    2011-09-01

    To develop an efficient genetic transformation system of chickpea (Cicer arietinum L.), callus derived from mature embryonic axes of variety P-362 was transformed with Agrobacterium tumefaciens strain LBA4404 harboring p35SGUS-INT plasmid containing the uidA gene encoding β-glucuronidase (GUS) and the nptII gene for kanamycin selection. Various factors affecting transformation efficiency were optimized; as Agrobacterium suspension at OD(600) 0.3 with 48 h of co-cultivation period at 20°C was found optimal for transforming 10-day-old MEA-derived callus. Inclusion of 200 μM acetosyringone, sonication for 4 s with vacuum infiltration for 6 min improved the number of GUS foci per responding explant from 1.0 to 38.6, as determined by histochemical GUS assay. For introducing the insect-resistant trait into chickpea, binary vector pRD400-cry1Ac was also transformed under optimized conditions and 18 T(0) transgenic plants were generated, representing 3.6% transformation frequency. T(0) transgenic plants reflected Mendelian inheritance pattern of transgene segregation in T(1) progeny. PCR, RT-PCR, and Southern hybridization analysis of T(0) and T(1) transgenic plants confirmed stable integration of transgenes into the chickpea genome. The expression level of Bt-Cry protein in T(0) and T(1) transgenic chickpea plants was achieved maximum up to 116 ng mg(-1) of soluble protein, which efficiently causes 100% mortality to second instar larvae of Helicoverpa armigera as analyzed by an insect mortality bioassay. Our results demonstrate an efficient and rapid transformation system of chickpea for producing non-chimeric transgenic plants with high frequency. These findings will certainly accelerate the development of chickpea plants with novel traits.

  14. Insect-resistant transgenic Pinus radiata.

    Science.gov (United States)

    Grace, Lynette J; Charity, Julia A; Gresham, Belinda; Kay, Nod; Walter, Christian

    2005-05-01

    Transgenic radiata pine (Pinus radiata D. Don) plants containing a Bacillus thuringiensis (Bt) toxin gene, crylAc, were produced by means of biolistic transformation of embryogenic tissue. Using the selectable marker gene nptII and corresponding geneticin selection, 20 independent transgenic lines from five genotypes were established. Over 200 plants regenerated from ten transgenic lines were successfully transferred to soil. The integration and expression of the introduced genes in transgenic tissue and/or plants were confirmed by PCR, Southern hybridisation and neomycin phosphotransferase II (NPTII) and Bt ELISA assays. Bioassays with larvae of the painted apple moth, Teia anartoides, demonstrated that transgenic plants displayed variable levels of resistance to insect damage, with one transgenic line being highly resistant to feeding damage.

  15. Insect Resistance Management in Bt Maize: Wild Host Plants of Stem Borers Do Not Serve as Refuges in Africa.

    Science.gov (United States)

    Van den Berg, J

    2017-02-01

    Resistance evolution by target pests threatens the sustainability of Bt maize in Africa where insect resistance management (IRM) strategies are faced by unique challenges. The assumptions, on which current IRM strategies for stem borers are based, are not all valid for African maize stem borer species. The high dose-refuge strategy which is used to delay resistance evolution relies heavily on the presence of appropriate refuges (non-Bt plants) where pests are not under selection pressure and where sufficient numbers of Bt-susceptible individuals are produced to mate with possible survivors on the Bt maize crop. Misidentification of stem borer species and inaccurate reporting on wild host plant diversity over the past six decades created the perception that grasses will contribute to IRM strategies for these pests in Africa. Desired characteristics of refuge plants are that they should be good pest hosts, implying that larval survival is high and that it produces sufficient numbers of high-quality moths. Refuge plants should also have large cover abundance in areas where Bt maize is planted. While wild host plants may suffice in IRM strategies for polyphagous pests, this is not the case with stenophagous pests. This review discusses data of ecological studies and stem borer surveys conducted over the past decade and shows that wild host plants are unsuitable for development and survival of sufficient numbers of stem borer individuals. These grasses rather act as dead-end-trap plants and do not comply with refuge requirements of producing 500 susceptible individuals for every one resistant individual that survives on Bt maize. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Insect-resistant transgenic plants in a multi-trophic context.

    Science.gov (United States)

    Groot, Astrid T; Dicke, Marcel

    2002-08-01

    So far, genetic engineering of plants in the context of insect pest control has involved insertion of genes that code for toxins, and may be characterized as the incorporation of biopesticides into classical plant breeding. In the context of pesticide usage in pest control, natural enemies of herbivores have received increasing attention, because carnivorous arthropods are an important component of insect pest control. However, in plant breeding programmes, natural enemies of herbivores have largely been ignored, although there are many examples that show that plant breeding affects the effectiveness of biological control. Negative influences of modified plant characteristics on carnivorous arthropods may induce population growth of new, even more harmful pest species that had no pest status prior to the pesticide treatment. Sustainable pest management will only be possible when negative effects on non-target, beneficial arthropods are minimized. In this review, we summarize the effects of insect-resistant crops and insect-resistant transgenic crops, especially Bt crops, from a food web perspective. As food web components, we distinguish target herbivores, non-target herbivores, pollinators, parasitoids and predators. Below-ground organisms such as Collembola, nematodes and earthworms should also be included in risk assessment studies, but have received little attention. The toxins produced in Bt plants retain their toxicity when bound to the soil, so accumulation of these toxins is likely to occur. Earthworms ingest the bound toxins but are not affected by them. However, earthworms may function as intermediaries through which the toxins are passed on to other trophic levels. In studies where effects of insect-resistant (Bt) plants on natural enemies were considered, positive, negative and no effects have been found. So far, most studies have concentrated on natural enemies of target herbivores. However, Bt toxins are structurally rearranged when they bind to

  17. Regeneration of transgenic citrus plants under non selective conditions results in high-frequency recovery of plants with silenced transgenes.

    Science.gov (United States)

    Domínguez, A; Fagoaga, C; Navarro, L; Moreno, P; Peña, L

    2002-06-01

    Insertion of foreign DNA into plant genomes frequently results in the recovery of transgenic plants with silenced transgenes. To investigate to what extent regeneration under selective conditions limits the recovery of transgenic plants showing gene silencing in woody species, Mexican lime [ Citrus aurantifolia (Christm.) Swing.] plants were transformed with the p25 coat protein gene of Citrus tristeza virus (CTV) with or without selection for nptII and uidA. Strikingly, more than 30% of the transgenic limes regenerated under non-selective conditions had silenced transgenes, and in all cases silencing affected all the three transgenes incorporated. These results indicate that the frequency of transgene silencing may be greatly underestimated when the rate of silencing is estimated from the number of regenerants obtained under selective conditions. To our knowledge, this is the first report in which the frequency of gene silencing after transformation has been quantified. When the integration pattern of T-DNA was analyzed in silenced and non-silenced lines, it was observed that inverted repeats as well as direct repeats and even single integrations were able to trigger gene silencing. Gene silencing has often been associated with the insertion of DNA sequences as inverted repeats. Interestingly, here, direct repeats and single-copy insertions were found in both silenced and non-silenced lines, suggesting that the presence of inverted-repeat T-DNAs and the subsequent formation of dsRNAs triggering gene silencing cannot account for all silencing events.

  18. The end of a myth – Bt(Cry1Ab) maize does not harm green lacewings

    Science.gov (United States)

    A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies...

  19. The natural refuge policy for Bt cotton (Gossypium L. in Pakistan – a situation analysis

    Directory of Open Access Journals (Sweden)

    Muhammad Sajjad Ali

    2013-07-01

    Full Text Available Bt cotton (event Cry1Ac was formally commercialized in Pakistan in 2010. However, there has been an increasing trend of planting unauthorized Bt cotton germplasm in farmers' fields since 2003 with a high rate of adoption in the core cotton areas especially in the province Punjab. The transgenic cotton technology has provided the growers with substantial economic benefits and has reduced their dependence on pesticides for pest control, especially against Helicoverpa armigera (Hubner. However, keeping in view the capacity of this insect to develop resistance against novel chemical formulations, it is easily speculated that Bt toxin, too, is no exception. Refuge crop policy for mono transgenic crop events has helped in delaying the rate of resistance evolution in the target pests. Thus, in Pakistan, where planting of structured refuge crops along Bt cotton fields is not mandatory, the effectiveness and durability of Bt cotton technology may decrease due to a number of factors which are discussed in this review.

  20. Insect resistance to Bt crops: lessons from the first billion acres.

    Science.gov (United States)

    Tabashnik, Bruce E; Brévault, Thierry; Carrière, Yves

    2013-06-01

    Evolution of resistance in pests can reduce the effectiveness of insecticidal proteins from Bacillus thuringiensis (Bt) produced by transgenic crops. We analyzed results of 77 studies from five continents reporting field monitoring data for resistance to Bt crops, empirical evaluation of factors affecting resistance or both. Although most pest populations remained susceptible, reduced efficacy of Bt crops caused by field-evolved resistance has been reported now for some populations of 5 of 13 major pest species examined, compared with resistant populations of only one pest species in 2005. Field outcomes support theoretical predictions that factors delaying resistance include recessive inheritance of resistance, low initial frequency of resistance alleles, abundant refuges of non-Bt host plants and two-toxin Bt crops deployed separately from one-toxin Bt crops. The results imply that proactive evaluation of the inheritance and initial frequency of resistance are useful for predicting the risk of resistance and improving strategies to sustain the effectiveness of Bt crops.

  1. Recent advances in development of marker-free transgenic plants ...

    Indian Academy of Sciences (India)

    2012-01-31

    Jan 31, 2012 ... During the efficient genetic transformation of plants with the gene of interest, some selectable marker genes are also used in order to identify the transgenic plant cells or tissues. Usually, antibiotic- or herbicide-selective agents and their corresponding resistance genes are used to introduce economically ...

  2. Recent advances in development of marker-free transgenic plants ...

    Indian Academy of Sciences (India)

    During the efficient genetic transformation of plants with the gene of interest, some selectable marker genes are also used in order to identify the transgenic plant cells or tissues. Usually, antibiotic- or herbicide-selective agents and their corresponding resistance genes are used to introduce economically valuable genes into ...

  3. Transgenic plants as green factories for vaccine production | Vinod ...

    African Journals Online (AJOL)

    Edible vaccine technology represents an alternative to fermentation based vaccine production system. Transgenic plants are used for the production of plant derived specific vaccines with native immunogenic properties stimulating both humoral and mucosal immune responses. Keeping in view the practical need of new ...

  4. Microbial fructan production in transgenic potato plants and tubers.

    NARCIS (Netherlands)

    Pilon-Smits, E.A.H.; Ebskamp, M.J.M.; Jeuken, M.J.W.; Meer, van der I.M.; Visser, R.G.F.; Weisbeek, P.J.; Smeekens, S.C.M.

    1996-01-01

    Fructans (fructose polymers) derived from plants usually have a very low degree of polymerisation (DP) and this limits the technical application of this versatile carbohydrate polymer. Previously we showed that the expression of bacterial fructosyltransferase genes in transgenic plants results in

  5. Early detection of field-evolved resistance to Bt cotton in China: cotton bollworm and pink bollworm.

    Science.gov (United States)

    Tabashnik, Bruce E; Wu, Kongming; Wu, Yidong

    2012-07-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins kill some major insect pests, but pests can evolve resistance and thereby reduce the effectiveness of such Bt crops. The main approach for slowing pest adaptation to Bt crops uses non-Bt host plants as "refuges" to increase survival of susceptible pests. To delay evolution of pest resistance to cotton producing Bt toxin Cry1Ac, several countries have required refuges of non-Bt cotton, while farmers in China have relied on "natural" refuges of non-Bt host plants other than cotton. This strategy is designed for cotton bollworm (Helicoverpa armigera), which attacks many crops and is the primary target of Bt cotton in China, but it does not apply to pink bollworm (Pectinophora gossypiella), which feeds almost entirely on cotton in China. Here we review evidence of field-evolved resistance to Cry1Ac by cotton bollworm in northern China and by pink bollworm in the Yangtze River Valley of China. For both pests, results of laboratory diet bioassays reveal significantly decreased susceptibility of field populations to Cry1Ac, yet field control failures of Bt cotton have not been reported. The early detection of resistance summarized here may spur countermeasures such as planting Bt cotton that produces two or more distinct toxins, increased planting of non-Bt cotton, and integration of other management tactics together with Bt cotton. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Galactose-extended glycans of antibodies produced by transgenic plants

    Science.gov (United States)

    Bakker, Hans; Bardor, Muriel; Molthoff, Jos W.; Gomord, Véronique; Elbers, Ingrid; Stevens, Lucas H.; Jordi, Wilco; Lommen, Arjen; Faye, Loïc; Lerouge, Patrice; Bosch, Dirk

    2001-01-01

    Plant-specific N-glycosylation can represent an important limitation for the use of recombinant glycoproteins of mammalian origin produced by transgenic plants. Comparison of plant and mammalian N-glycan biosynthesis indicates that β1,4-galactosyltransferase is the most important enzyme that is missing for conversion of typical plant N-glycans into mammalian-like N-glycans. Here, the stable expression of human β1,4-galactosyltransferase in tobacco plants is described. Proteins isolated from transgenic tobacco plants expressing the mammalian enzyme bear N-glycans, of which about 15% exhibit terminal β1,4-galactose residues in addition to the specific plant N-glycan epitopes. The results indicate that the human enzyme is fully functional and localizes correctly in the Golgi apparatus. Despite the fact that through the modified glycosylation machinery numerous proteins have acquired unusual N-glycans with terminal β1,4-galactose residues, no obvious changes in the physiology of the transgenic plants are observed, and the feature is inheritable. The crossing of a tobacco plant expressing human β1,4-galactosyltransferase with a plant expressing the heavy and light chains of a mouse antibody results in the expression of a plantibody that exhibits partially galactosylated N-glycans (30%), which is approximately as abundant as when the same antibody is produced by hybridoma cells. These results are a major step in the in planta engineering of the N-glycosylation of recombinant antibodies. PMID:11226338

  7. A recombinase-mediated transcriptional induction system in transgenic plants

    DEFF Research Database (Denmark)

    Hoff, T; Schnorr, K M; Mundy, J

    2001-01-01

    We constructed and tested a Cre-loxP recombination-mediated vector system termed pCrox for use in transgenic plants. In this system, treatment of Arabidopsis under inducing conditions mediates an excision event that removes an intervening piece of DNA between a promoter and the gene to be expressed......-mediated GUS activation. Induction was shown to be possible at essentially any stage of plant growth. This single vector system circumvents the need for genetic crosses required by other, dual recombinase vector systems. The pCrox system may prove particularly useful in instances where transgene over...

  8. [Effects of phytase transgenic corn planting on soil nematode community].

    Science.gov (United States)

    Zhao, Zong-Chao; Su, Ying; Mou, Wen-Ya; Liu, Man-Qiang; Chen, Xiao-Yun; Chen, Fa-Jun

    2014-04-01

    A healthy soil ecosystem is essential for nutrient cycling and energy conversion, and the impact of exogenous genes from genetically modified crops had aroused wide concerns. Phytase transgenic corn (i. e., the inbred line BVLA430101) was issued a bio-safety certificate on 27 September 2009 in China, which could improve the efficiency of feed utilization, reduce environmental pollution caused by animal manure. In this study, the abundance of trophic groups, community structure and ecological indices of soil nematodes were studied over the growing cycle of phytase transgenic corn (ab. transgenic corn) and control conventional parental corn (ab. control corn) in the field. Totally 29 and 26 nematode genera were isolated from transgenic corn and control corn fields, respectively. The abundances of bacterivores and omnivores-predators, the total number of soil nematodes, and the Shannon index (H) were significantly greater under transgenic corn than under control corn, while the opposite trend was found for the relative abundance of herbivores and the maturity index (Sigma MI) of soil nematodes. Repeated-measures analysis of variance (ANOVA) did not detect any significant effects of transgenic corn on the composition and abundance of nematode trophic groups and ecological indices of soil nematodes. Furthermore, the Student-T test showed that the abundances of bacterivores and omnivores-predators and the total number of soil nematodes during the milk-ripe stage were significant higher in the transgenic corn field than in the control corn field. The effects of transgenic corn planting on soil nematodes might be related to the increase in the nitrogen content of field soil under transgenic corn compared to control corn.

  9. TRANSGENIC PLANTS: ENVIRONMENTAL PERSISTENCE AND EFFECTS ON SOIL AND PLANT ECOSYSTEMS

    Science.gov (United States)

    The genetic engineering of plants has facilitated the production of valuable agricultural and forestry crops. Transgenic plants have been created that have increased resistance to pests, herbicides, pathogens, and environmental stress, enhanced qualitative and quantitative trait...

  10. Surge in insect resistance to transgenic crops and prospects for sustainability.

    Science.gov (United States)

    Tabashnik, Bruce E; Carrière, Yves

    2017-10-11

    Transgenic crops have revolutionized insect pest control, but their effectiveness has been reduced by evolution of resistance in pests. We analyzed global monitoring data reported during the first two decades of transgenic crops, with each case representing the responses of one pest species in one country to one insecticidal protein from Bacillus thuringiensis (Bt). The cases of pest resistance to Bt crystalline (Cry) proteins produced by transgenic crops increased from 3 in 2005 to 16 in 2016. By contrast, in 17 other cases there was no decrease in pest susceptibility to Bt crops, including the recently introduced transgenic corn that produces a Bt vegetative insecticidal protein (Vip). Recessive inheritance of pest resistance has favored sustained susceptibility, but even when inheritance is not recessive, abundant refuges of non-Bt host plants have substantially delayed resistance. These insights may inform resistance management strategies to increase the durability of current and future transgenic crops.

  11. Field assessment of Bt cry1Ah corn pollen on the survival, development and behavior of Apis mellifera ligustica.

    Science.gov (United States)

    Dai, Ping-Li; Zhou, Wei; Zhang, Jie; Cui, Hong-Juan; Wang, Qiang; Jiang, Wei-Yu; Sun, Ji-Hu; Wu, Yan-Yan; Zhou, Ting

    2012-05-01

    Honeybees may be exposed to insecticidal proteins from transgenic plants via pollen. An assessment of the impact of such exposures on the honeybee is an essential part of the risk assessment process for transgenic Bacillus thuringiensis corn. A field trial was conducted to evaluate the effect of transgenic Bt cry1Ah corn on the honeybee Apis mellifera ligustica. Colonies of honeybees were moved to Bt or non-Bt corn fields during anthesis and then sampled to record their survival, development and behavior. No differences in immature stages, worker survival, bee body weight, hypopharyngeal gland weight, colony performance, foraging activity or olfactory learning abilities were detected between colonies that were placed in non-Bt corn fields and those placed in Bt corn fields. We conclude that cry1Ah corn carries no risk for the survival, development, colony performance or behavior of the honeybee A. mellifera ligustica. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Transgenic plants for enhanced phytoremediation of toxic explosives.

    Science.gov (United States)

    Van Aken, Benoit

    2009-04-01

    Phytoremediation of organic pollutants, such as explosives, is often a slow and incomplete process, potentially leading to the accumulation of toxic metabolites that can be further introduced into the food chain. During the past decade, plants have been genetically modified to overcome the inherent limitations of plant detoxification capabilities, following a strategy similar to the development of transgenic crop. Bacterial genes encoding enzymes involved in the breakdown of explosives, such as nitroreductase and cytochrome P450, have been introduced in higher plants, resulting in significant enhancement of plant tolerance, uptake, and detoxification performances. Transgenic plants exhibiting biodegradation capabilities of microorganisms bring the promise of an efficient and environmental-friendly technology for cleaning up polluted soils.

  13. Transgenic plants for enhanced biodegradation and phytoremediation of organic xenobiotics.

    Science.gov (United States)

    Abhilash, P C; Jamil, Sarah; Singh, Nandita

    2009-01-01

    Phytoremediation--the use of plants to clean up polluted soil and water resources--has received much attention in the last few years. Although plants have the inherent ability to detoxify xenobiotics, they generally lack the catabolic pathway for the complete degradation of these compounds compared to microorganisms. There are also concerns over the potential for the introduction of contaminants into the food chain. The question of how to dispose of plants that accumulate xenobiotics is also a serious concern. Hence the feasibility of phytoremediation as an approach to remediate environmental contamination is still somewhat in question. For these reasons, researchers have endeavored to engineer plants with genes that can bestow superior degradation abilities. A direct method for enhancing the efficacy of phytoremediation is to overexpress in plants the genes involved in metabolism, uptake, or transport of specific pollutants. Furthermore, the expression of suitable genes in root system enhances the rhizodegradation of highly recalcitrant compounds like PAHs, PCBs etc. Hence, the idea to amplify plant biodegradation of xenobiotics by genetic manipulation was developed, following a strategy similar to that used to develop transgenic crops. Genes from human, microbes, plants, and animals are being used successfully for this venture. The introduction of these genes can be readily achieved for many plant species using Agrobacterium tumefaciens-mediated plant transformation or direct DNA methods of gene transfer. One of the promising developments in transgenic technology is the insertion of multiple genes (for phase 1 metabolism (cytochrome P450s) and phase 2 metabolism (GSH, GT etc.) for the complete degradation of the xenobiotics within the plant system. In addition to the use of transgenic plants overexpressed with P450 and GST genes, various transgenic plants expressing bacterial genes can be used for the enhanced degradation and remediation of herbicides, explosives

  14. Transgenic plants and associated bacteria for phytoremediation of chlorinated compounds.

    Science.gov (United States)

    Van Aken, Benoit; Doty, Sharon Lafferty

    2010-01-01

    Phytoremediation is the use of plants for the treatment of environmental pollution, including chlorinated organics. Although conceptually very attractive, removal and biodegradation of chlorinated pollutants by plants is a rather slow and inefficient process resulting in incomplete treatment and potential release of toxic metabolites into the environment. In order to overcome inherent limitations of plant metabolic capabilities, plants have been genetically modified, following a strategy similar to the development of transgenic crops: genes from bacteria, fungi, and mammals involved in the metabolism of organic contaminants, such as cytochrome P-450 and glutathione S-transferase, have been introduced into higher plants, resulting in significant improvement of tolerance, removal, and degradation of pollutants. Recently, plant-associated bacteria have been recognized playing a significant role in phytoremediation, leading to the development of genetically modified rhizospheric and endophytic bacteria with improved biodegradation capabilities. Transgenic plants and associated bacteria constitute a new generation of genetically modified organisms for efficient and environmental-friendly treatment of polluted soil and water. This review focuses on recent advances in the development of transgenic plants and bacteria for the treatment of chlorinated pollutants, including chlorinated solvents, polychlorinated phenols, and chlorinated herbicides.

  15. Toxins for Transgenic Resistance to Hemipteran Pests

    Directory of Open Access Journals (Sweden)

    Bryony C. Bonning

    2012-06-01

    Full Text Available The sap sucking insects (Hemiptera, which include aphids, whiteflies, plant bugs and stink bugs, have emerged as major agricultural pests. The Hemiptera cause direct damage by feeding on crops, and in some cases indirect damage by transmission of plant viruses. Current management relies almost exclusively on application of classical chemical insecticides. While the development of transgenic crops expressing toxins derived from the bacterium Bacillus thuringiensis (Bt has provided effective plant protection against some insect pests, Bt toxins exhibit little toxicity against sap sucking insects. Indeed, the pest status of some Hemiptera on Bt-transgenic plants has increased in the absence of pesticide application. The increased pest status of numerous hemipteran species, combined with increased prevalence of resistance to chemical insecticides, provides impetus for the development of biologically based, alternative management strategies. Here, we provide an overview of approaches toward transgenic resistance to hemipteran pests.

  16. Feeding Behaviour on Host Plants May Influence Potential Exposure to Bt Maize Pollen of Aglais Urticae Larvae (Lepidoptera, Nymphalidae

    Directory of Open Access Journals (Sweden)

    Andreas Lang

    2015-08-01

    Full Text Available Non-target butterfly larvae may be harmed by feeding on host plants dusted with Bt maize pollen. Feeding patterns of larvae and their utilization of host plants can affect the adverse Bt impact because the maize pollen is distributed unequally on the plant. In a field study, we investigated the feeding of larvae of the Small Tortoiseshell, Aglais urticae, on nettles, Urtica dioica. Young larvae used smaller host plants than older larvae. In general, the position of the larvae was in the top part of the host plant, but older larvae showed a broader vertical distribution on the nettles. Leaf blades and leaf tips were the plant parts most often consumed. Leaf veins were consumed but midribs were fed on to a lesser extent than other plant veins, particularly by young larvae. The feeding behavior of the larvae may increase possible exposure to Bt maize pollen because pollen densities are expected to be higher on the top parts and along leaf veins of nettles.

  17. Leaf proteome analysis of transgenic plants expressing antiviral antibodies.

    Science.gov (United States)

    Di Carli, Mariasole; Villani, Maria Elena; Renzone, Giovanni; Nardi, Luca; Pasquo, Alessandra; Franconi, Rosella; Scaloni, Andrea; Benvenuto, Eugenio; Desiderio, Angiola

    2009-02-01

    The expression of exogenous antibodies in plant is an effective strategy to confer protection against viral infection or to produce molecules with pharmaceutical interest. However, the acceptance of the transgenic technology to obtain self-protecting plants depends on the assessment of their substantial equivalence compared to non-modified crops with an established history of safe use. In fact, the possibility exists that the introduction of transgenes in plants may alter expression of endogenous genes and/or normal production of metabolites. In this study, we investigated whether the expression in plant of recombinant antibodies directed against viral proteins may influence the host leaf proteome. Two transgenic plant models, generated by Agrobacterium tumefaciens-mediated transformation, were analyzed for this purpose, namely, Lycopersicon esculentum cv. MicroTom and Nicotiana benthamiana, expressing recombinant antibodies against cucumber mosaic virus and tomato spotted wilt virus, respectively. To obtain a significant representation of plant proteomes, optimized extraction procedures have been devised for each plant species. The proteome repertoire of antibody-expressing and control plants was compared by 2-DE associated to DIGE technology. Among the 2000 spots detected within the gels, about 10 resulted differentially expressed in each transgenic model and were identified by MALDI-TOF PMF and muLC-ESI-IT-MS/MS procedures. Protein variations were restricted to a limited number of defined differences with an average ratio below 2.4. Most of the differentially expressed proteins were related to photosynthesis or defense function. The overall results suggest that the expression of recombinant antibodies in both systems does not significantly alter the leaf proteomic profile, contributing to assess the biosafety of resistant plants expressing antiviral antibodies.

  18. Transgenic plants as vital components of integrated pest management

    NARCIS (Netherlands)

    Kos, Martine; van Loon, J.J.A.; Dicke, M.; Vet, L.E.M.

    2009-01-01

    Although integrated pest management (IPM) strategies have been developed worldwide, further improvement of IPM effectiveness is required. The use of transgenic technology to create insect-resistant plants can offer a solution to the limited availability of highly insect-resistant cultivars.

  19. Pathogen resistance of transgenic tobacco plants producing caffeine.

    Science.gov (United States)

    Kim, Yun-Soo; Sano, Hiroshi

    2008-02-01

    Caffeine (1,3,7-trimethylxanthine) is a typical purine alkaloid, and produced by a variety of plants such as coffee and tea. Its physiological function, however, is not completely understood, but chemical defense against pathogens and herbivores, and allelopathic effects against competing plant species have been proposed. Previously, we constructed transgenic tobacco plants, which produced caffeine up to 5 microg per gram fresh weight of leaves, and showed them to repel caterpillars of tobacco cutworms (Spodoptera litura). In the present study, we found that these transgenic plants constitutively expressed defense-related genes encoding pathogenesis-related (PR)-1a and proteinase inhibitor II under non-stressed conditions. We also found that they were highly resistant against pathogens, tobacco mosaic virus and Pseudomonas syringae. Expression of PR-1a and PR-2 was higher in transgenic plants than in wild-type plants during infection. Exogenously applied caffeine to wild-type tobacco leaves exhibited the similar resistant activity. These results suggested that caffeine stimulated endogenous defense system of host plants through directly or indirectly activating gene expression. This assumption is essentially consistent with the idea of chemical defense, in which caffeine may act as one of signaling molecules to activate defense response. It is thus conceivable that the effect of caffeine is bifunctional; direct interference with pest metabolic pathways, and activation of host defense systems.

  20. Quantitation of transgenic Bt event-176 maize using double quantitative competitive polymerase chain reaction and capillary gel electrophoresis laser-induced fluorescence.

    Science.gov (United States)

    García-Cañas, Virginia; Cifuentes, Alejandro; González, Ramón

    2004-04-15

    In this work, a new procedure useful to quantitatively analyze genetically modified organisms (GMOs) in foods is described and applied to analyze transgenic Bt Event-176 maize. The method developed consists of coamplifications of specific DNA maize sequences with internal standards using quantitative competitive PCR (QC-PCR). The QC-PCR products are quantitatively analyzed using a capillary gel electrophoresis (CGE) with laser-induced fluorescence detection (LIF) method developed at our laboratory that utilizes a physically adsorbed coating. The CGE-LIF procedure allows the use of internal standards differing by only 10 bp from the original target fragments, to our knowledge, the smallest size difference that can be found in the bibliography for QC-PCR of GMOs. A spectrofluorometric procedure using ROX reference dye is proposed to solve calibration problems of input DNA concentration. It is demonstrated that the use of ROX drastically enhances the accuracy of the quantitative analysis by QC-PCR. Reproducibility of analysis times and corrected peak areas (measured as target/competitor PCR products ratio) for the CGE-LIF separations are determined to be better than 0.91 and 1.93% (RSD, n = 15) respectively, for three different days. It is shown that CGE-LIF provides better resolution and a signal/noise ratio improvement of approximately 700-fold compared to slab gel electrophoresis. The good possibilities in terms of quantitative analysis of GMOs provided by this new method are confirmed by determining the Bt Event-176 maize content in certified reference maize powder and food samples of known composition. This procedure opens the possibility for accurate quantitation of multiple GMOs in a single run.

  1. Decrease in catalase activity of Folsomia candida fed a Bt rice diet

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Yiyang, E-mail: yuanyy@ioz.ac.cn [State Key Laboratory of Integrated Management of Pest and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Ke Xin, E-mail: xinke@sibs.ac.cn [Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032 (China); Chen Fajun, E-mail: fajunchen@njau.edu.cn [College of Plant Protection, Department of Entomology, Nanjing Agricultural University, Nanjing 210095 (China); Krogh, Paul Henning, E-mail: phk@dmu.dk [Department of Bioscience, University of Aarhus, P.O. Box 314, Vejlsoevej 25, DK-8600 Silkeborg (Denmark); Ge Feng, E-mail: gef@ioz.ac.cn [State Key Laboratory of Integrated Management of Pest and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101 (China)

    2011-12-15

    Here we report the effects of three Bt-rice varieties and their non-Bt conventional isolines on biological traits including survival, reproduction, and the activities of three antioxidant enzymes superoxide dismutase, catalase and peroxidase, in the Collembolan, Folsomia candida. The reproduction was significantly lower when fed Kemingdao and Huahui1 than those feeding on their non-GM near-isogenic varieties Xiushui and Minghui63 respectively, this can be explained by the differences of plant compositions depended on variety of rice. The catalase activity of F. candida was significantly lower when fed the Bt-rice variety Kemingdao compared to the near-isogenic non-Bt-rice variety Xiushui. This suggests that some Bt-rice varieties may impose environmental stress to collembolans. We emphasize that changes in activity of antioxidant enzymes of non-target organisms are important in understanding the ecological consequences for organisms inhabiting transgenic Bt-rice plantations. - Highlights: > We examine the effects of Bt-rice on Folsomia candida with laboratory test. > The reproduction of F. candida was decreased by two Bt-rice varieties. > Decreased reproduction caused by the differences of varieties or C/N ratio of rice. > The catalase activity was decreased by Bt-rice Kemingdao. > Some Bt-rice may impose environmental stress on NTOs. - The catalase of the collembolan (Folsomia candida) was decreased when fed Bt-rice, Kemingdao.

  2. Soil microbial biomass and root growth in Bt and non-Bt cotton

    Science.gov (United States)

    Tan, D. K. Y.; Broughton, K.; Knox, O. G.; Hulugalle, N. R.

    2012-04-01

    The introduction of transgenic Bacillus thuringiensis (Bt) cotton (Gossypium hirsutum L.) has had a substantial impact on pest management in the cotton industry. While there has been substantial research done on the impact of Bt on the above-ground parts of the cotton plant, less is known about the effect of Bt genes on below ground growth of cotton and soil microbial biomass. The aim of this research was to test the hypothesis that Bt [Sicot 80 BRF (Bollgard II Roundup Ready Flex®)] and non-Bt [Sicot 80 RRF (Roundup Ready Flex®)] transgenic cotton varieties differ in root growth and root turnover, carbon indices and microbial biomass. A field experiment was conducted in Narrabri, north-western NSW. The experimental layout was a randomised block design and used minirhizotron and core break and root washing methods to measure cotton root growth and turnover during the 2008/09 season. Root growth in the surface 0-0.1 m of the soil was measured using the core break and root washing methods, and that in the 0.1 to 1 m depth was measured with a minirhizotron and an I-CAP image capture system. These measurements were used to calculate root length per unit area, root carbon added to the soil through intra-seasonal root death, carbon in roots remaining at the end of the season and root carbon potentially added to the soil. Microbial biomass was also measured using the ninhydrin reactive N method. Root length densities and length per unit area of non-Bt cotton were greater than Bt cotton. There were no differences in root turnover between Bt and non-Bt cotton at 0-1 m soil depth, indicating that soil organic carbon stocks may not be affected by cotton variety. Cotton variety did not have an effect on soil microbial biomass. The results indicate that while there are differences in root morphology between Bt and non-Bt cotton, these do not change the carbon turnover dynamics in the soil.

  3. [Comparison between transgenic insect-resistant cotton expressing Cry1Ac protein and its parental variety in rhizospheric fungal diversity].

    Science.gov (United States)

    Pan, Jian-Gang; Jiao, Hai-Hua; Bai, Zhi-Hui; Qi, Hong-Yan; Ma, An-Zhou; Zhuang, Guo-qiang; Zhang, Hong-xun

    2014-11-01

    The dynamics of rhizospheric fungal diversity and biomass at different sampling stages associated with two transgenic insectresistant cottons expressing Cry1Ac protein and their control varieties were studied under greenhouse conditions, followed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and quantitative real-time polymerase chain reaction (Q-PCR), in order to evaluate the ecological security of planting transgenic cotton expressing Cry1Ac protein. The results indicated that the fungal superior bands in rhizosphere of transgenic Bt cotton were similar with that of control cotton at four sampling stages, the more obvious difference in the blurred bands among transgenic Bt cotton, JM20 and SHIYUAN321 was detected. The rhizospheric fungal biomass of transgenic Bt cotton SGK321 was significantly lower than that of its parental control cotton at seedling stage, while the slight decrease in fungal biomass of transgenic Bt cotton XP188 was detected at boll forming stage, the ill-defined decrease, even growing tendency in two transgenic Bt cottons was detected at other stages. However, the difference of rhizospheric fungal community compositions and biomass was not only existed between transgenic cotton and its control, but also between SHIYUAN321 and JM20, and the same phenomenon was also detected between transgenic Bt cotton SGK321 and XP188. Hence, Bt protein is not the only incentive resulting in the difference in fungal community composition and diversity, the decrease in biomass between transgenic cotton and untransgenic cotton, different cotton varieties has an effect on them.

  4. Transgenic plants for the production of veterinary vaccines.

    Science.gov (United States)

    Dus Santos, María José; Wigdorovitz, Andrés

    2005-06-01

    The expression of antigens in transgenic plants has been increasingly used in the development of experimental vaccines, particularly oriented to the development of edible vaccines. Hence, this technology becomes highly suitable to express immunogenic proteins from pathogens. Foot and mouth disease virus, bovine rotavirus and bovine viral diarrhoea virus are considered to be the most important causative agents of economic loss of cattle production in Argentina, and they are thus optimal candidates for alternative means of immunization. Here, we present a review of our results corresponding to the expression of immunogenic proteins from these three viruses in alfalfa transgenic plants, and we discuss the possibility of using them for the development of plant-based vaccines.

  5. Transgenic Strategies for Enhancement of Nematode Resistance in Plants

    Directory of Open Access Journals (Sweden)

    Muhammad A. Ali

    2017-05-01

    Full Text Available Plant parasitic nematodes (PPNs are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants.

  6. Transgenic Strategies for Enhancement of Nematode Resistance in Plants

    Science.gov (United States)

    Ali, Muhammad A.; Azeem, Farrukh; Abbas, Amjad; Joyia, Faiz A.; Li, Hongjie; Dababat, Abdelfattah A.

    2017-01-01

    Plant parasitic nematodes (PPNs) are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants. PMID:28536595

  7. Transgenic loblolly pine (Pinus taeda L.) plants expressing a modified delta-endotoxin gene of Bacillus thuringiensis with enhanced resistance to Dendrolimus punctatus Walker and Crypyothelea formosicola Staud.

    Science.gov (United States)

    Tang, Wei; Tian, Yingchuan

    2003-02-01

    A synthetic version of the CRY1Ac gene of Bacillus thuringiensis has been used for the transformation of loblolly pine (Pinus taeda L.) using particle bombardment. Mature zygotic embryos were used to be bombarded and to generate organogenic callus and transgenic regenerated plants. Expression vector pB48.215 DNA contained a synthetic Bacillus thuringiensis (B.t.) CRY1Ac coding sequence flanked by the double cauliflower mosaic virus (CaMV) 35S promoter and nopaline synthase (NOS) terminator sequences, and the neomycin phosphotransferase II (NPTII) gene controlled by the promoter of the nopaline synthase gene was introduced into loblolly pine tissues by particle bombardment. The transformed tissues were proliferated and selected on media with kanamycin. Shoot regeneration was induced from the kanamycin-resistant calli, and transgenic plantlets were then produced. More than 60 transformed plants from independent transformation events were obtained for each loblolly pine genotype tested. The integration and expression of the introduced genes in the transgenic loblolly pine plants was confirmed by polymerase chain reactions (PCR) analysis, by Southern hybridization, by Northern blot analysis, and by Western blot analysis. Effective resistance of transgenic plants against Dendrolimus punctatus Walker and Crypyothelea formosicola Staud was verified in feeding bioassays with the insects. The transgenic plants recovered could represent a good opportunity to analyse the impact of genetic engineering of pine for sustainable resistance to pests using a B. thuringiensis insecticidal protein. This protocol enabled the routine transformation of loblolly pine plants that were previously difficult to transform.

  8. Effect of pyramiding Bt and CpTI genes on resistance of cotton to Helicoverpa armigera (Lepidoptera: Noctuidae) under laboratory and field conditions.

    Science.gov (United States)

    Cui, Jinjie; Luo, Junyu; Van Der Werf, Wopke; Ma, Yan; Xia, Jingyuan

    2011-04-01

    Transgenic cotton (Cossypium hirsutum L.) varieties, adapted to China, have been bred that express two genes for resistance to insects, the CrylAc gene from Bacillus thuringiensis (Berliner) (Bt), and a trypsin inhibitor gene from cowpea (CpTI). Effectiveness of the double gene modification in conferring resistance to cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was studied in laboratory and field experiments. In each experiment, performance of Bt+CpTI cotton was compared with Bt cotton and to a conventional nontransgenic variety. Larval survival was lower on both types of transgenic variety, compared with the conventional cotton. Survival of first-, second-, and third-stage larvae was lower on Bt+CpTI cotton than on Bt cotton. Plant structures differed in level of resistance, and these differences were similar on Bt and Bt + CpTI cotton. Likewise, seasonal trends in level of resistance in different plant structures were similar in Bt and Bt+CpTI cotton. Both types of transgenic cotton interfered with development of sixth-stage larvae to adults, and no offspring was produced by H. armigera that fed on Bt or Bt+CpTI cotton from the sixth stage onward. First-, second-, and third-stage larvae spent significantly less time feeding on transgenic cotton than on conventional cotton, and the reduction in feeding time was significantly greater on Bt+CpTI cotton than on Bt cotton. Food conversion efficiency was lower on transgenic varieties than on conventional cotton, but there was no significant difference between Bt and Bt+CpTI cotton. In 3-yr field experimentation, bollworm densities were greatly suppressed on transgenic as compared with conventional cotton, but no significant differences between Bt and Bt+CpTI cotton were found. Overall, the results from laboratory work indicate that introduction of the CpTI gene in Bt cotton raises some components of resistance in cotton against H. armigera, but enhanced control of H. armigera under field

  9. A New Method for in Situ Measurement of Bt-Maize Pollen Deposition on Host-Plant Leaves

    Directory of Open Access Journals (Sweden)

    Rudolph Vögel

    2011-02-01

    Full Text Available Maize is wind pollinated and produces huge amounts of pollen. In consequence, the Cry toxins expressed in the pollen of Bt maize will be dispersed by wind in the surrounding vegetation leading to exposure of non-target organisms (NTO. NTO like lepidopteran larvae may be affected by the uptake of Bt-pollen deposited on their host plants. Although some information is available to estimate pollen deposition on host plants, recorded data are based on indirect measurements such as shaking or washing off pollen, or removing pollen with adhesive tapes. These methods often lack precision and they do not include the necessary information such as the spatial and temporal variation of pollen deposition on the leaves. Here, we present a new method for recording in situ the amount and the distribution of Bt-maize pollen deposited on host plant leaves. The method is based on the use of a mobile digital microscope (Dino-Lite Pro, including DinoCapture software, which can be used in combination with a notebook in the field. The method was evaluated during experiments in 2008 to 2010. Maize pollen could be correctly identified and pollen deposition as well as the spatial heterogeneity of maize pollen deposition was recorded on maize and different lepidopteran host plants (Centaurea scabiosa, Chenopodium album, Rumex spp., Succina pratensis and Urtica dioica growing adjacent to maize fields.

  10. Marker-free, tissue-specific expression of Cry1Ab as a safe transgenic strategy for insect resistance in rice plants.

    Science.gov (United States)

    Qi, Yongbin; Chen, Lei; He, Xiuling; Jin, Qingsheng; Zhang, Xiaoming; He, Zuhua

    2013-01-01

    Rice is the major food resource for nearly half of the global population; however, insect infestation could severely affect the production of this staple food. To improve rice insect resistance and reduce the levels of Bt toxin released into the environment, the Cry1Ab gene was conjugated to the rice rbcS promoter to express Bt toxin in specific tissues of transgenic plants. Eight marker-free, T(2) lines were separated from the T(0) cotransformants. Using RT-PCR, high levels of Cry1Ab expression were detected in the leaf but not in the seed. The Cry1Ab protein level ranged from 1.66 to 3.31 µg g(-1) in the leaves of four transgenic lines, but was barely detectable in their seeds by ELISA. Bioassays showed that the mortality rate of silkworm larvae feeding on mulberry leaves dipped in transgenic rice flour and pollen was less than that of the positive control (KMD), and that their average weight was higher than that of KMD, suggesting that the Cry1Ab protein was not expressed in the seed and pollen. The transgene conferred a high level of resistance to insects and biosafety to the rice plants, which could be directly used in rice breeding. Copyright © 2012 Society of Chemical Industry.

  11. Bt Jute Expressing Fused δ-Endotoxin Cry1Ab/Ac for Resistance to Lepidopteran Pests

    Science.gov (United States)

    Majumder, Shuvobrata; Sarkar, Chirabrata; Saha, Prosanta; Gotyal, Bheemanna S.; Satpathy, Subrata; Datta, Karabi; Datta, Swapan K.

    2018-01-01

    Jute (Corchorus sp.) is naturally occurring, biodegradable, lignocellulosic-long, silky, golden shiny fiber producing plant that has great demands globally. Paper and textile industries are interested in jute because of the easy availability, non-toxicity and high yield of cellulosic biomass produced per acre in cultivation. Jute is the major and most industrially used bast fiber-producing crop in the world and it needs protection from insect pest infestation that decreases its yield and quality. Single locus integration of the synthetically fused cry1Ab/Ac gene of Bacillus thuringiensis (Bt) in Corchorus capsularis (JRC 321) by Agrobacterium tumefaciens-mediated shoot tip transformation provided 5 potent Bt jute lines BT1, BT2, BT4, BT7 and BT8. These lines consistently expressed the Cry1Ab/Ac endotoxin ranging from 0.16 to 0.35 ng/mg of leaf, in the following generations (analyzed upto T4). The effect of Cry1Ab/Ac endotoxin was studied against 3 major Lepidopteran pests of jute- semilooper (Anomis sabulifera Guenee), hairy caterpillar (Spilarctia obliqua Walker) and indigo caterpillar (Spodoptera exigua Hubner) by detached leaf and whole plant insect bioassay on greenhouse-grown transgenic plants. Results confirm that larvae feeding on transgenic plants had lower food consumption, body size, body weight and dry weight of excreta compared to non-transgenic controls. Insect mortality range among transgenic feeders was 66–100% for semilooper and hairy caterpillar and 87.50% for indigo caterpillar. Apart from insect resistance, the transgenic plants were at par with control plants in terms of agronomic parameters and fiber quality. Hence, these Bt jutes in the field would survive Lepidopteran pest infestation, minimize harmful pesticide usage and yield good quality fiber. PMID:29354143

  12. Transgenic Plants Lower the Costs of Cellulosic Biofuels (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-11-01

    A new transgenic maize was observed to be less recalcitrant than wild-type biomass, as manifested through lower severity requirements to achieve comparable levels of conversion. Expression of a single gene derived from bacteria in plants has resulted in transgenic plants that are easier and cheaper to convert into biofuels. Part of the high production cost of cellulosic biofuels is the relatively poor accessibility of substrates to enzymes due to the strong associations between plant cell wall components. This biomass recalcitrance makes costly thermochemical pretreatment necessary. Scientists at the National Renewable Energy Laboratory (NREL) have created transgenic maize expressing an active glycosyl hydrolase enzyme, E1 endoglucanase, originally isolated from a thermophilic bacterium, Acidothermus cellulolyticus. This engineered feedstock was observed to be less recalcitrant than wild-type biomass when subjected to reduced severity pretreatments and post-pretreatment enzymatic hydrolysis. This reduction in recalcitrance was manifested through lower severity requirements to achieve comparable levels of conversion of wild-type biomass. The improvements observed are significant enough to positively affect the economics of the conversion process through decreased capital construction costs and decreased degradation products and inhibitor formation.

  13. Pyramids of QTLs enhance host-plant resistance and Bt-mediated resistance to leaf-chewing insects in soybean.

    Science.gov (United States)

    Ortega, María A; All, John N; Boerma, H Roger; Parrott, Wayne A

    2016-04-01

    QTL-M and QTL-E enhance soybean resistance to insects. Pyramiding these QTLs with cry1Ac increases protection against Bt-tolerant pests, presenting an opportunity to effectively deploy Bt with host-plant resistance genes. Plant resistance to leaf-chewing insects minimizes the need for insecticide applications, reducing crop production costs and pesticide concerns. In soybean [Glycine max (L.) Merr.], resistance to a broad range of leaf-chewing insects is found in PI 229358 and PI 227687. PI 229358's resistance is conferred by three quantitative trait loci (QTLs): M, G, and H. PI 227687's resistance is conferred by QTL-E. The letters indicate the soybean Linkage groups (LGs) on which the QTLs are located. This study aimed to determine if pyramiding PI 229358 and PI 227687 QTLs would enhance soybean resistance to leaf-chewing insects, and if pyramiding these QTLs with Bt (cry1Ac) enhances resistance against Bt-tolerant pests. The near-isogenic lines (NILs): Benning(ME), Benning(MGHE), and Benning(ME+cry1Ac) were developed. Benning(ME) and Benning(MGHE) were evaluated in detached-leaf and greenhouse assays with soybean looper [SBL, Chrysodeixis includens (Walker)], corn earworm [CEW, Helicoverpa zea (Boddie)], fall armyworm [FAW, Spodoptera frugiperda (J.E. Smith)], and velvetbean caterpillar [VBC, Anticarsia gemmatalis (Hübner)]; and in field-cage assays with SBL. Benning(ME+cry1Ac) was tested in detached-leaf assays against SBL, VBC, and Southern armyworm [SAW, Spodoptera eridania (Cramer)]. In the detached-leaf assay, Benning(ME) showed the strongest antibiosis against CEW, FAW, and VBC. In field-cage conditions, Benning(ME) and Benning(MGHE) suffered 61 % less defoliation than Benning. Benning(ME+cry1Ac) was more resistant than Benning(ME) and Benning (cry1Ac) against SBL and SAW. Agriculturally relevant levels of resistance in soybean can be achieved with just two loci, QTL-M and QTL-E. ME+cry1Ac could present an opportunity to protect the durability of Bt

  14. Transgenic indica rice plants harboring a synthetic cry2A* gene of Bacillus thuringiensis exhibit enhanced resistance against lepidopteran rice pests.

    Science.gov (United States)

    Chen, Hao; Tang, Wei; Xu, Caiguo; Li, Xianghua; Lin, Yongjun; Zhang, Qifa

    2005-11-01

    A novel synthetic cry2A* gene was introduced into the elite indica rice restorer line Minghui 63 by Agrobacterium-mediated transformation. A total of 102 independent transformants were obtained. Among them, 71 transformants were positive cry2A* plants according to PCR analysis. Four highly insect-resistant lines with single-copy insertion (designated as 2A-1, 2A-2, 2A-3, and 2A-4) were selected based on field assessment and Southern blot analysis in the T(1) generation. All four transgenic lines showed Mendelian segregation by seed germination on 1/2 MS medium containing Basta. Homozygous transgenic plants were selected according to germination ratio (100%) in the T2 generation. Cry2A* protein concentrations were determined in homozygous transgenic lines, their derived hybrids, and their backcross offspring. The Cry2A* protein concentrations of four homozygous transgenic lines ranged from 9.65 to 12.11 microg/g of leaf fresh weight. There was little variation in the hybrids and backcross offspring. Insect bioassays were conducted in both the laboratory and field. All four transgenic lines were significantly resistant to lepidopteran rice pests. These cry2A* transgenic lines can be used to produce insect-resistant hybrids and serve as a resistant source for the development of two-toxin Bt rice.

  15. Pollen- and Seed-Mediated Transgene Flow in Commercial Cotton Seed Production Fields

    Science.gov (United States)

    Heuberger, Shannon; Ellers-Kirk, Christa; Tabashnik, Bruce E.; Carrière, Yves

    2010-01-01

    Background Characterizing the spatial patterns of gene flow from transgenic crops is challenging, making it difficult to design containment strategies for markets that regulate the adventitious presence of transgenes. Insecticidal Bacillus thuringiensis (Bt) cotton is planted on millions of hectares annually and is a potential source of transgene flow. Methodology/Principal Findings Here we monitored 15 non-Bt cotton (Gossypium hirsutum, L.) seed production fields (some transgenic for herbicide resistance, some not) for gene flow of the Bt cotton cry1Ac transgene. We investigated seed-mediated gene flow, which yields adventitious Bt cotton plants, and pollen-mediated gene flow, which generates outcrossed seeds. A spatially-explicit statistical analysis was used to quantify the effects of nearby Bt and non-Bt cotton fields at various spatial scales, along with the effects of pollinator abundance and adventitious Bt plants in fields, on pollen-mediated gene flow. Adventitious Bt cotton plants, resulting from seed bags and planting error, comprised over 15% of plants sampled from the edges of three seed production fields. In contrast, pollen-mediated gene flow affected less than 1% of the seed sampled from field edges. Variation in outcrossing was better explained by the area of Bt cotton fields within 750 m of the seed production fields than by the area of Bt cotton within larger or smaller spatial scales. Variation in outcrossing was also positively associated with the abundance of honey bees. Conclusions/Significance A comparison of statistical methods showed that our spatially-explicit analysis was more powerful for understanding the effects of surrounding fields than customary models based on distance. Given the low rates of pollen-mediated gene flow observed in this study, we conclude that careful planting and screening of seeds could be more important than field spacing for limiting gene flow. PMID:21152426

  16. Pollen- and seed-mediated transgene flow in commercial cotton seed production fields.

    Directory of Open Access Journals (Sweden)

    Shannon Heuberger

    Full Text Available BACKGROUND: Characterizing the spatial patterns of gene flow from transgenic crops is challenging, making it difficult to design containment strategies for markets that regulate the adventitious presence of transgenes. Insecticidal Bacillus thuringiensis (Bt cotton is planted on millions of hectares annually and is a potential source of transgene flow. METHODOLOGY/PRINCIPAL FINDINGS: Here we monitored 15 non-Bt cotton (Gossypium hirsutum, L. seed production fields (some transgenic for herbicide resistance, some not for gene flow of the Bt cotton cry1Ac transgene. We investigated seed-mediated gene flow, which yields adventitious Bt cotton plants, and pollen-mediated gene flow, which generates outcrossed seeds. A spatially-explicit statistical analysis was used to quantify the effects of nearby Bt and non-Bt cotton fields at various spatial scales, along with the effects of pollinator abundance and adventitious Bt plants in fields, on pollen-mediated gene flow. Adventitious Bt cotton plants, resulting from seed bags and planting error, comprised over 15% of plants sampled from the edges of three seed production fields. In contrast, pollen-mediated gene flow affected less than 1% of the seed sampled from field edges. Variation in outcrossing was better explained by the area of Bt cotton fields within 750 m of the seed production fields than by the area of Bt cotton within larger or smaller spatial scales. Variation in outcrossing was also positively associated with the abundance of honey bees. CONCLUSIONS/SIGNIFICANCE: A comparison of statistical methods showed that our spatially-explicit analysis was more powerful for understanding the effects of surrounding fields than customary models based on distance. Given the low rates of pollen-mediated gene flow observed in this study, we conclude that careful planting and screening of seeds could be more important than field spacing for limiting gene flow.

  17. Enhancer-promoter interference and its prevention in transgenic plants.

    Science.gov (United States)

    Singer, Stacy D; Cox, Kerik D; Liu, Zongrang

    2011-05-01

    Biotechnology has several advantages over conventional breeding for the precise engineering of gene function and provides a powerful tool for the genetic improvement of agronomically important traits in crops. In particular, it has been exploited for the improvement of multiple traits through the simultaneous introduction or stacking of several genes driven by distinct tissue-specific promoters. Since transcriptional enhancer elements have been shown to override the specificity of nearby promoters in a position- and orientation-independent manner, the co-existence of multiple enhancers/promoters within a single transgenic construct could be problematic as it has the potential to cause the mis-expression of transgene product(s). In order to develop strategies with, which to prevent such interference, a clear understanding of the mechanisms underlying enhancer-mediated activation of target promoters, as well as the identification of DNA sequences that function to block these interactions in plants, will be necessary. To date, little is known concerning enhancer function in plants and only a very limited number of enhancer-blocking insulators that operate in plant species have been identified. In this review, we discuss the current knowledge surrounding enhancer-promoter interactions, as well as possible means of minimizing such interference during plant transformation experiments.

  18. TRANSGENIC PLANTS - INSECTICIDAL TOXIN IN ROOT EXUDATES FROM BT CORN. (R826107)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  19. Detrimental effect of expression of Bt endotoxin Cry1Ac on in vitro regeneration, in vivo growth and development of tobacco and cotton transgenics.

    Science.gov (United States)

    Rawat, Preeti; Singh, Amarjeet Kumar; Ray, Krishna; Chaudhary, Bhupendra; Kumar, Sanjeev; Gautam, Taru; Kanoria, Shaveta; Kaur, Gurpreet; Kumar, Paritosh; Pental, Deepak; Burma, Pradeep Kumar

    2011-06-01

    High levels of expression of the cry1Ac gene from Bacillus thuringiensis cannot be routinely achieved in transgenic plants despite modifications made in the gene to improve its expression. This has been attributed to the instability of the transcript in a few reports. In the present study, based on the genetic transformation of cotton and tobacco, we show that the expression of the Cry1Ac endotoxin has detrimental effects on both the in vitro and in vivo growth and development of transgenic plants. A number of experiments on developing transgenics in cotton with different versions of cry1Ac gene showed that the majority of the plants did not express any Cry1Ac protein. Based on Southern blot analysis, it was also observed that a substantial number of lines did not contain the cry1Ac gene cassette although they contained the marker gene nptII. More significantly, all the lines that showed appreciable levels of expression were found to be phenotypically abnormal. Experiments on transformation of tobacco with different constructs expressing the cry1Ac gene showed that in vitro regeneration was inhibited by the encoded protein. Further, out of a total of 145 independent events generated with the different cry1Ac gene constructs in tobacco, only 21 showed expression of the Cry1Ac protein, confirming observations made in cotton that regenerants that express high levels of the Cry1Ac protein are selected against during regeneration of transformed events. This problem was circumvented by targeting the Cry1Ac protein to the chloroplast, which also significantly improved the expression of the protein.

  20. FROM Qutn TO Bt COTTON: DEVELOPMENT, ADOPTION AND PROSPECTS. A REVIEW.

    Science.gov (United States)

    Maik, W; Abid, M A; Cheema, H M N; Khan, A A; Iqbal, M Z; Qayyum, A; Hanif, M; Bibi, N; Yuan, S N; Yasmeen, A; Mahmood, A; Ashraf, J

    2015-01-01

    Cotton has unique history of domestication, diversification, and utilization. Globally it is an important cash crop that provides raw material for textile industry. The story of cotton started from human civilization and the climax arrived with the efforts of developing transgenic cotton for various traits. Though conventional breeding brought steady improvement in developing resistance against biotic stresses but recent success story of gene transferfrom Bacillus thuringiensis into cotton showed game changing effects on cotton cultivation. Amongst various families of insecticidal proteins Bt Cry-toxins received more attention because of specificity against receptors on the cell membranes of insect midgut epithelial cells. Rapid Bt cotton adoption by farmers due to its economic and environmental benefits has changed the landscape of cotton cultivation in many countries. But the variable expression of Bt transgene in the newly developed Bt cotton genotypes in tropical environment is questionable. Variability of toxin level in different plant parts at various life stage of plant is an outcome of genotypic interaction with environmental factors. Temporal gene expression of Cry1Ac is also blamed for the epigenetic background in which transgene has been inserted. The presence of genotypes with sub-lethal level of Bt toxin might create resistance in Lepidopteron insects, limiting the use of Bt cotton in future, with the opportunityfor other resistance development strategies to get more attention like gene stacking. Until the farmers get access to more recent technology, best option is to delay the development of resistance by applying Insect Resistance Management (IRM) strategies.

  1. Transgenic plants expressing GLK1 and CCA1 having increased nitrogen assimilation capacity

    Science.gov (United States)

    Coruzzi, Gloria [New York, NY; Gutierrez, Rodrigo A [Santiago, CL; Nero, Damion C [Woodside, NY

    2012-04-10

    Provided herein are compositions and methods for producing transgenic plants. In specific embodiments, transgenic plants comprise a construct comprising a polynucleotide encoding CCA1, GLK1 or bZIP1, operably linked to a plant-specific promote, wherein the CCA1, GLK1 or bZIP1 is ectopically overexpressed in the transgenic plants, and wherein the promoter is optionally a constitutive or inducible promoter. In other embodiments, transgenic plants in which express a lower level of CCA1, GLK1 or bZIP1 are provided. Also provided herein are commercial products (e.g., pulp, paper, paper products, or lumber) derived from the transgenic plants (e.g., transgenic trees) produced using the methods provided herein.

  2. Transformation of pecan and regeneration of transgenic plants.

    Science.gov (United States)

    McGranahan, G H; Leslie, C A; Dandekar, A M; Uratsu, S L; Yates, I E

    1993-09-01

    A gene transfer system developed for walnut (Juglans regia L.) was successfully applied to pecan (Carya illinoensis [Wang] K. Koch). Repetitively embryogenic somatic embryos derived from open-pollinated seed of 'Elliott', 'Wichita', and 'Schley' were co-cultivated with Agrobacterium strain EHA 101/pCGN 7001, which contains marker genes for beta-glucuronidase activity and resistance to kanamycin. Several modifications of the standard walnut transformation techniques were tested, including a lower concentration of kanamycin and a modified induction medium, but these treatments had no measurable effect on efficiency of transformation. Nineteen of the 764 viable inoculated embryos produced transgenic subclones; 13 of these were from the line 'Elliott'6, 3 from 'Schley'5/3, and 3 from 'Wichita'9. Transgenic embryos of 'Wichita'9 germinated most readily and three subclones were successfully micropropagated. Three transgenic plants of one of these subclones were obtained by grafting the tissue cultured shoots to seedling pecan rootstock in the greenhouse. Gene insertion, initially detected by GUS activity, was confirmed by detection of integrated T-DNA sequences using Southern analysis.

  3. EXPRESSION OF CHITINASE GENE IN TRANSGENIC RAPE PLANTS

    Directory of Open Access Journals (Sweden)

    Lu Longdou

    2005-08-01

    Full Text Available The hypocotyl and cotyledon of Brassica napus L. H165 and Brassica juncea DB3 were transformed with chitinase gene and herbicide-resistance gene by co-culture with Agrobacterium tumefacients LBA4404, and rape plants were obtained which could grow on the medium containing herbicide. The PCR result showed that exotic genes were integrated in the genome of the rape. Further study was performed to determine the impact of temperature on the transgenic rate and the differentiation of explants.

  4. Accurate measure of transgene copy number in crop plants using droplet digital PCR

    Science.gov (United States)

    Genetic transformation is a powerful means for the improvement of crop plants, but requires labor- and resource-intensive methods. An efficient method for identifying single-copy transgene insertion events from a population of independent transgenic lines is desirable. Currently, transgene copy numb...

  5. Transgenic tobacco plants expressing BoRS1 gene from Brassica ...

    Indian Academy of Sciences (India)

    The transgenic status and transgene expression of the transgenic plants was confirmed by polymerase chain reaction (PCR) analysis, Southern hybridization and semi-quantitative one step RT-PCR analysis respectively. Subsequently, the growth status under water stress, and physiological responses to water stress of ...

  6. Plant mitochondrial genome: “A sweet and safe home'' for transgene ...

    African Journals Online (AJOL)

    Transfer of transgene through pollens to related plant species is a big environmental concern. Mitochondrion is also a superb and putative aspirant for transgene containment like plastids. Having its own transcription and translation machinery, and maternal inheritance gives assurance of transgene containment with high ...

  7. The end of a myth – Bt (Cry1Ab maize does not harm green lacewings

    Directory of Open Access Journals (Sweden)

    Joerg eRomeis

    2014-08-01

    Full Text Available A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies, some authors still refer to them as evidence that Bt maize harms beneficial species. We provide a comprehensive review of the studies evaluating the effects of Bt (Cry1Ab maize on C. carnea. The evidence indicates that this important predator is not affected by Bt maize or by the produced Cry1Ab protein. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies.

  8. The end of a myth-Bt (Cry1Ab) maize does not harm green lacewings.

    Science.gov (United States)

    Romeis, Jörg; Meissle, Michael; Naranjo, Steven E; Li, Yunhe; Bigler, Franz

    2014-01-01

    A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies, some authors still refer to them as evidence that Bt maize harms beneficial species. We provide a comprehensive review of the studies evaluating the effects of Bt (Cry1Ab) maize on C. carnea. The evidence indicates that this important predator is not affected by Bt maize or by the produced Cry1Ab protein. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies.

  9. The end of a myth—Bt (Cry1Ab) maize does not harm green lacewings

    Science.gov (United States)

    Romeis, Jörg; Meissle, Michael; Naranjo, Steven E.; Li, Yunhe; Bigler, Franz

    2014-01-01

    A concern with Bt-transgenic insect-resistant plants is their potential to harm non-target organisms. Early studies reported that Cry1Ab-producing Bt maize and purified Cry1Ab harmed larvae of the green lacewing, Chrysoperla carnea. Although these effects could not be confirmed in subsequent studies, some authors still refer to them as evidence that Bt maize harms beneficial species. We provide a comprehensive review of the studies evaluating the effects of Bt (Cry1Ab) maize on C. carnea. The evidence indicates that this important predator is not affected by Bt maize or by the produced Cry1Ab protein. We discuss how conceptual models can assist environmental risk assessments, and we emphasize the importance of robust and reproducible studies. PMID:25161661

  10. Spatio-Temporal Variation in Landscape Composition May Speed Resistance Evolution of Pests to Bt Crops.

    Science.gov (United States)

    Ives, Anthony R; Paull, Cate; Hulthen, Andrew; Downes, Sharon; Andow, David A; Haygood, Ralph; Zalucki, Myron P; Schellhorn, Nancy A

    2017-01-01

    Transgenic crops that express insecticide genes from Bacillus thuringiensis (Bt) are used worldwide against moth and beetle pests. Because these engineered plants can kill over 95% of susceptible larvae, they can rapidly select for resistance. Here, we use a model for a pyramid two-toxin Bt crop to explore the consequences of spatio-temporal variation in the area of Bt crop and non-Bt refuge habitat. We show that variability over time in the proportion of suitable non-Bt breeding habitat, Q, or in the total area of Bt and suitable non-Bt habitat, K, can increase the overall rate of resistance evolution by causing short-term surges of intense selection. These surges can be exacerbated when temporal variation in Q and/or K cause high larval densities in refuges that increase density-dependent mortality; this will give resistant larvae in Bt fields a relative advantage over susceptible larvae that largely depend on refuges. We address the effects of spatio-temporal variation in a management setting for two bollworm pests of cotton, Helicoverpa armigera and H. punctigera, and field data on landscape crop distributions from Australia. Even a small proportion of Bt fields available to egg-laying females when refuges are sparse may result in high exposure to Bt for just a single generation per year and cause a surge in selection. Therefore, rapid resistance evolution can occur when Bt crops are rare rather than common in the landscape. These results highlight the need to understand spatio-temporal fluctuations in the landscape composition of Bt crops and non-Bt habitats in order to design effective resistance management strategies.

  11. Expression of Cry1Ac in transgenic tobacco plants under the control of a wound-inducible promoter (AoPR1) isolated from Asparagus officinalis to control Heliothis virescens and Manduca sexta.

    Science.gov (United States)

    Gulbitti-Onarici, Selma; Zaidi, Mohsin Abbas; Taga, Ibrahim; Ozcan, Sebahattin; Altosaar, Illimar

    2009-07-01

    Expression of cry1Ac gene from Bacillus thuringiensis (Bt) was evaluated under the control of a wound-inducible AoPR1 promoter from Asparagus officinalis in transgenic tobacco plants. The leaves of transgenic plants were mechanically wounded to evaluate the activity of the AoPR1 promoter in driving the expression of Cry1Ac protein at the wound site. Our results indicate that mechanical wounding of transgenic plants was effective in inducing the expression of Cry1Ac protein. As a result of this induction, the accumulated levels of Cry1Ac protein increased during 6-72 h post-wounding period. The leaves of transgenic tobacco plants were evaluated for resistance against Heliothis virescens and Manduca sexta in insect bioassays in two different ways. The detached tobacco leaves were either fed directly to the insect larvae or they were first mechanically wounded followed by a 72 h post-wounding feeding period. Complete protection of mechanically wounded leaves of transgenic plants was observed within 24 h of the bioassay. The leaves of transgenic plants fed directly (without pre-wounding) to the larvae achieved the same level of protection between 24 and 72 h of the bioassay.

  12. Role of transgenic plants in agriculture and biopharming.

    Science.gov (United States)

    Ahmad, Parvaiz; Ashraf, Muhammad; Younis, Muhammad; Hu, Xiangyang; Kumar, Ashwani; Akram, Nudrat Aisha; Al-Qurainy, F

    2012-01-01

    At present, environmental degradation and the consistently growing population are two main problems on the planet earth. Fulfilling the needs of this growing population is quite difficult from the limited arable land available on the globe. Although there are legal, social and political barriers to the utilization of biotechnology, advances in this field have substantially improved agriculture and human life to a great extent. One of the vital tools of biotechnology is genetic engineering (GE) which is used to modify plants, animals and microorganisms according to desired needs. In fact, genetic engineering facilitates the transfer of desired characteristics into other plants which is not possible through conventional plant breeding. A variety of crops have been engineered for enhanced resistance to a multitude of stresses such as herbicides, insecticides, viruses and a combination of biotic and abiotic stresses in different crops including rice, mustard, maize, potato, tomato, etc. Apart from the use of GE in agriculture, it is being extensively employed to modify the plants for enhanced production of vaccines, hormones, etc. Vaccines against certain diseases are certainly available in the market, but most of them are very costly. Developing countries cannot afford the disease control through such cost-intensive vaccines. Alternatively, efforts are being made to produce edible vaccines which are cheap and have many advantages over the commercialized vaccines. Transgenic plants generated for this purpose are capable of expressing recombinant proteins including viral and bacterial antigens and antibodies. Common food plants like banana, tomato, rice, carrot, etc. have been used to produce vaccines against certain diseases like hepatitis B, cholera, HIV, etc. Thus, the up- and down-regulation of desired genes which are used for the modification of plants have a marked role in the improvement of genetic crops. In this review, we have comprehensively discussed the role

  13. Morphogenetic and chemical stability of long-term maintained Agrobacterium-mediated transgenic Catharanthus roseus plants.

    Science.gov (United States)

    Verma, Priyanka; Sharma, Abhishek; Khan, Shamshad Ahmad; Mathur, Ajay Kumar; Shanker, Karuna

    2015-01-01

    Transgenic Catharanthus roseus plants (transgenic Dhawal [DT] and transgenic Nirmal [NT]) obtained from the Agrobacterium tumefaciens and Agrobacterium rhizognenes-mediated transformations, respectively, have been maintained in vitro for 5 years. Plants were studied at regular intervals for various parameters such as plant height, leaf size, multiplication rate, alkaloid profile and presence of marker genes. DT plant gradually lost the GUS gene expression and it was not detected in the fifth year while NT plant demonstrated the presence of genes rolA, rolB and rolC even in the fifth year, indicating the more stable nature of Ri transgene. Vindoline content in the DT was two times more than in non-transformed control plants. Alkaloid and tryptophan profiles were almost constant during the 5 years. The cluster analysis revealed that the DT plant is more close to the control Nirmal plant followed by NT plant.

  14. Human anti-rhesus D IgG1 antibody produced in transgenic plants

    DEFF Research Database (Denmark)

    Bouquin, Thomas; Thomsen, Mads; Nielsen, Leif Kofoed

    2002-01-01

    Transgenic plants represent an alternative to cell culture systems for producing cheap and safe antibodies for diagnostic and therapeutic use. To evaluate the functional properties of a 'plantibody', we generated transgenic Arabidopsis plants expressing full-length human IgG1 against the Rhesus D...

  15. Translatability of a plant-mRNA strongly influences its accumulation in transgenic plants.

    Science.gov (United States)

    Vancanneyt, G; Rosahl, S; Willmitzer, L

    1990-05-25

    Current knowledge of parameters affecting RNA stability is very restricted in plants. Here we investigated factors which might contribute to the stability of a particular plant messenger RNA. To this end, insertion and deletion mutants were made in two different exons and an intron of the transcribed region of a well characterised patatin gene (pgT5). Mutant genes were expressed under the control of a strong leaf-stem specific promoter (ST-LS1) and analysed in vivo in transgenic tobacco plants. Northern analysis revealed the importance of the translatability of the mature messenger RNA with respect to its accumulation in transgenic plants. Enlargement of the 3' non-translated region by several hundred base-pairs reduced the steady state mRNA level slightly; the introduction of a stop codon leading to premature termination of translation of the RNA led to a dramatic decrease of the steady state mRNA level.

  16. Field-evolved insect resistance to Bt crops: definition, theory, and data.

    Science.gov (United States)

    Tabashnik, Bruce E; Van Rensburg, J B J; Carrière, Yves

    2009-12-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins for insect pest control have been successful, but their efficacy is reduced when pests evolve resistance. Here we review the definition of field-evolved resistance, the relationship between resistance and field control problems, the theory underlying strategies for delaying resistance, and resistance monitoring methods. We also analyze resistance monitoring data from five continents reported in 41 studies that evaluate responses of field populations of 11 lepidopteran pests to four Bt toxins produced by Bt corn and cotton. After more than a decade since initial commercialization of Bt crops, most target pest populations remain susceptible, whereas field-evolved resistance has been documented in some populations of three noctuid moth species: Spodoptera frugiperda (J. E. Smith) to Cry1F in Bt corn in Puerto Rico, Busseola fusca (Fuller) to CrylAb in Bt corn in South Africa, and Helicoverpa zea (Boddie) to CrylAc and Cry2Ab in Bt cotton in the southeastern United States. Field outcomes are consistent with predictions from theory, suggesting that factors delaying resistance include recessive inheritance of resistance, abundant refuges of non-Bt host plants, and two-toxin Bt crops deployed separately from one-toxin Bt crops. The insights gained from systematic analyses of resistance monitoring data may help to enhance the durability of transgenic insecticidal crops. We recommend continued use of the longstanding definition of resistance cited here and encourage discussions about which regulatory actions, if any, should be triggered by specific data on the magnitude, distribution, and impact of field-evolved resistance.

  17. Minimizing the unpredictability of transgene expression in plants: the role of genetic insulators.

    Science.gov (United States)

    Singer, Stacy D; Liu, Zongrang; Cox, Kerik D

    2012-01-01

    The genetic transformation of plants has become a necessary tool for fundamental plant biology research, as well as the generation of engineered plants exhibiting improved agronomic and industrial traits. However, this technology is significantly hindered by the fact that transgene expression is often highly variable amongst independent transgenic lines. Two of the major contributing factors to this type of inconsistency are inappropriate enhancer-promoter interactions and chromosomal position effects, which frequently result in mis-expression or silencing of the transgene, respectively. Since the precise, often tissue-specific, expression of the transgene(s) of interest is often a necessity for the successful generation of transgenic plants, these undesirable side effects have the potential to pose a major challenge for the genetic engineering of these organisms. In this review, we discuss strategies for improving foreign gene expression in plants via the inclusion of enhancer-blocking insulators, which function to impede enhancer-promoter communication, and barrier insulators, which block the spread of heterochromatin, in transgenic constructs. While a complete understanding of these elements remains elusive, recent studies regarding their use in genetically engineered plants indicate that they hold great promise for the improvement of transgene expression, and thus the future of plant biotechnology.

  18. THE TRANSGENIC PLANTS – ADVANTAGES REGARDING THEIR CULTIVATION AND POTENTIALLY RISKS CONCERNING THE FOOD SAFETY

    OpenAIRE

    Dana PUSTA; PAŞCA, Ioan; MORAR, Roman; SOBOLU, Rodica; Camelia RĂDUCU; ODAGIU Antonia

    2009-01-01

    During the last decades the genetic modifi ed organisms (GMO) have started to “conquer”, little by little our lives. The most widely used are the trangenic plants, because they have bigger productions and they are resistant to different pests. In the beginning, the spread of the transgenic plants was controlled, but today many countries cultivate genetic modifi ed plants without any control. Among these countries Romania is ahead, starting the cultivation of the transgenic plants in 1999, ver...

  19. A QTL that enhances and broadens Bt insect resistance in soybean.

    Science.gov (United States)

    Walker, David R; Narvel, James M; Boerma, H Roger; All, John N; Parrott, Wayne A

    2004-09-01

    Effective strategies are needed to manage insect resistance to Bacillus thuringiensis (Bt) proteins expressed in transgenic crops. To evaluate a multiple resistance gene pyramiding strategy, eight soybean (Glycine max) lines possessing factorial combinations of two quantitative trait loci (QTLs) from plant introduction (PI) 229358 and a synthetic Bt cry1Ac gene were developed using marker-assisted selection with simple sequence repeat markers. Field studies were conducted in 2000 and 2001 to evaluate resistance to corn earworm (Helicoverpa zea) and soybean looper (Pseudoplusia includens), and detached leaf bioassays were used to test antibiosis resistance to Bt-resistant and Bt-susceptible strains of tobacco budworm (TBW; Heliothis virescens). Based on defoliation in the field and larval weight gain on detached leaves, lines carrying a combination of cry1Ac and the PI 229358 allele at a QTL on linkage group M were significantly more resistant to the lepidopteran pests, including the Bt-resistant TBW strain, than were the other lines. This is the first report of a complementary additive effect between a Bt transgene and a plant insect resistance QTL with an uncharacterized mode of action that was introgressed using marker-assisted selection.

  20. Transgenic strategies to confer resistance against viruses in rice plants

    Directory of Open Access Journals (Sweden)

    Takahide eSasaya

    2014-01-01

    Full Text Available Rice (Oryza sativa L. is cultivated in more than 100 countries and supports nearly half of the world’s population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. In an effort to improve control, many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA-interference (RNAi, also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral Achilles’ heel gene to target for RNAi attack when engineering plants.

  1. Transgenic strategies to confer resistance against viruses in rice plants.

    Science.gov (United States)

    Sasaya, Takahide; Nakazono-Nagaoka, Eiko; Saika, Hiroaki; Aoki, Hideyuki; Hiraguri, Akihiro; Netsu, Osamu; Uehara-Ichiki, Tamaki; Onuki, Masatoshi; Toki, Seichi; Saito, Koji; Yatou, Osamu

    2014-01-13

    Rice (Oryza sativa L.) is cultivated in more than 100 countries and supports nearly half of the world's population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. Many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA interference (RNAi), also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral "Achilles' heel" gene to target for RNAi attack when engineering plants.

  2. A point mutation (L1015F) of the voltage-sensitive sodium channel gene associated with lambda-cyhalothrin resistance in Apolygus lucorum (Meyer-Dür) population from the transgenic Bt cotton field of China.

    Science.gov (United States)

    Zhen, Congai; Gao, Xiwu

    2016-02-01

    In China, the green mirid bug, Apolygus lucorum (Meyer-Dür), has caused severe economic damage to many kinds of crops, especially the cotton and jujubes. Pyrethroid insecticides have been widely used for controlling this pest in the transgenic Bt cotton field. Five populations of A. lucorum collected from cotton crops at different locations in China were evaluated for lambda-cyhalothrin resistance. The results showed that only the population collected from Shandong Province exhibited 30-fold of resistance to lambda-cyhalothrin. Neither PBO nor DEF had obvious synergism when compared the synergistic ratio between SS and RR strain which was originated from the Shandong population. Besides, there were no statistically significant differences (p>0.05) in the carboxylesterase, glutathione S-transferase, or 7-ethoxycoumarin O-deethylase activities between the Shandong population and the laboratory susceptible strain (SS). The full-length sodium channel gene named AlVSSC encoding 2028 amino acids was obtained by RT-PCR and rapid amplification of cDNA ends (RACE). One single point mutation L1015F in the AlVSSC was detected only in the Shandong population. Our results revealed that the L1015F mutation associated with pyrethroid resistance was identified in A. lucorum populations in China. These results will be useful for the rational chemical control of A. lucorum in the transgenic Bt cotton field. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Acquiring transgenic tobacco plants with insect resistance and glyphosate tolerance by fusion gene transformation.

    Science.gov (United States)

    Sun, He; Lang, Zhihong; Zhu, Li; Huang, Dafang

    2012-10-01

    The advantages of gene 'stacking' or 'pyramiding' are obvious in genetically modified (GM) crops, and several different multi-transgene-stacking methods are available. Using linker peptides for multiple gene transformation is considered to be a good method to meet a variety of needs. In our experiment, the Bt cry1Ah gene, which encodes the insect-resistance protein, and the mG ( 2 ) -epsps gene, which encodes the glyphosate-tolerance protein, were connected by a 2A or LP4/2A linker. Linker 2A is a peptide from the foot-and-mouth disease virus (FMDV) that has self-cleavage activity. LP4 is a peptide from Raphanus sativus seeds that has a recognition site and is cleaved by a protease. LP4/2A is a hybrid peptide that contains the first 9 amino acids of LP4 and 20 amino acids from 2A. We used the linker peptide to construct four coordinated expression vectors: pHAG, pHLAG, pGAH and pGLAH. Two single gene expression vectors, pSAh and pSmG(2), were used as controls. The six expression vectors and the pCAMBIA2301 vector were transferred into tobacco by Agrobacterium tumefaciens-mediated transformation, and 529 transformants were obtained. Molecular detection and bioassay detection data demonstrated that the transgenic tobaccos possessed good pest resistance and glyphosate tolerance. The two genes in the fusion vector were expressed simultaneously. The plants with the genes linked by the LP4/2A peptide showed better pest resistance and glyphosate tolerance than the plants with the genes linked by 2A. The expression level of the two genes linked by LP4/2A was not significantly different from the single gene vector. Key message The expression level of the two genes linked by LP4/2A was higher than those linked by 2A and was not significantly different from the single gene vector.

  4. [Cotton laccase gene overexpression in transgenic Populus alba var. pyramidalis and its effects on the lignin biosynthesis in transgenic plants].

    Science.gov (United States)

    Wang, Ji; Zhu, Mu Lan; Wei, Zhi Ming

    2008-02-01

    Using petioles as explants, a cotton laccase cDNA (GaLA C1) was introduced into Populus alba var. pyramidalis by A. tumefaciens-mediated transformation. PCR and Southern blot analysis indicated that transgene was stably integrated into the genome of transformants. Enzyme assay showed that laccase activity was obviously increased in transformants. As compared with untransformed control, total lignin content in all tested transgenic lines was elevated in varying degrees (as highest as 21.5%). Histochemical staining of lignin further confirmed that overexpressing GaLA C1 could result in increased lignin content in transformants. Together, our data strongly suggested that GaLA C1 may participate in lignin synthesis and this is the first direct transgenic evidence for the involvement of plant laccases in lignification.

  5. Effect of Iranian Bt cotton on life table of Bemisia tabaci (Hemiptera: Alyrodidae and Cry 1Ab detection in the whitefly honeydew

    Directory of Open Access Journals (Sweden)

    Solmaz Azimi

    2016-09-01

    Full Text Available Transgenic cotton expressing the Cry 1Ab protein of Bacillus thuringiensis developing against Helocoverpa armigera may be affect on secondary pest such as Bemisia tabaci. In this study effects of Bt cotton on demographic parameters of B. tabaci were assessed and the data analyzed using the age specific, two-sex life table parameters. Results showed that getting to the adulthood stage, was faster on non-Bt cotton in comparison with Bt cotton. Also the fecundity was higher on non-Bt cotton than that on Bt cotton. Some of the population parameters (r, R0 and T of B. tabaci were affected by the Bt cotton significantly. The intrinsic rate of increase (r on Bt and non-Bt cotton was 0.07 day-1 and 0.1 day-1 , respectively. The net reproductive rate (R0 was 20.68 and 15.04 offspring/individual on Bt and non-Bt cotton, respectively. Mean generation time (T in non-Bt cotton was 27.22 and 34.62 days in Bt cotton. The results indicated that the life history of B. tabaci in the laboratory condition was influenced by host plant quality and Bt cotton was not a suitable host for B. tabaci. The western immunoblot method showed that the Cry protein detection in honeydew was positive which indicated that the Cry protein was ingested. Results revealed that the transgenic cotton could adversely affect the secondary pest and the natural enemies which feed on such pests as a host or their honeydew as a food source should be considered.

  6. Accurate measurement of transgene copy number in crop plants using droplet digital PCR

    Science.gov (United States)

    Technical abstract: Genetic transformation is a powerful means for the improvement of crop plants, but requires labor and resource intensive methods. An efficient method for identifying single copy transgene insertion events from a population of independent transgenic lines is desirable. Currently ...

  7. Detection of probable marker-free transgene-positive rice plants ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 91; Issue 2. Detection of probable marker-free transgene-positive rice plants resistant to rice tungro disease from backcross progenies of transgenic Pusa Basmati 1. Somnath Roy Amrita Banerjee Jayanta Tarafdar Bijoy K. Senapati. Research Note Volume 91 Issue 2 August ...

  8. High susceptibility of Bt maize to aphids enhances the performance of parasitoids of lepidopteran pests.

    Directory of Open Access Journals (Sweden)

    Cristina A Faria

    Full Text Available Concerns about possible undesired environmental effects of transgenic crops have prompted numerous evaluations of such crops. So-called Bt crops receive particular attention because they carry bacteria-derived genes coding for insecticidal proteins that might negatively affect non-target arthropods. Here we show a remarkable positive effect of Bt maize on the performance of the corn leaf aphid Rhopalosiphum maidis, which in turn enhanced the performance of parasitic wasps that feed on aphid honeydew. Within five out of six pairs that were evaluated, transgenic maize lines were significantly more susceptible to aphids than their near-isogenic equivalents, with the remaining pair being equally susceptible. The aphids feed from the phloem sieve element content and analyses of this sap in selected maize lines revealed marginally, but significantly higher amino acid levels in Bt maize, which might partially explain the observed increased aphid performance. Larger colony densities of aphids on Bt plants resulted in an increased production of honeydew that can be used as food by beneficial insects. Indeed, Cotesia marginiventris, a parasitoid of lepidopteran pests, lived longer and parasitized more pest caterpillars in the presence of aphid-infested Bt maize than in the presence of aphid-infested isogenic maize. Hence, depending on aphid pest thresholds, the observed increased susceptibility of Bt maize to aphids may be either a welcome or an undesirable side effect.

  9. Enhanced drought tolerance in transgenic Leymus chinensis plants with constitutively expressed wheat TaLEA3.

    Science.gov (United States)

    Wang, Lijuan; Li, Xiaofeng; Chen, Shuangyan; Liu, Gongshe

    2009-02-01

    Leymus chinensis is an important grassland perennial grass. However, its drought tolerance requires to be improved. LEA (late embryogenesis abundant) genes are believed to confer resistance to drought and water deficiency. Using Agrobacterium-mediated transformation, a wheat LEA gene, TaLEA(3), was integrated into L. chinensis. The transgenic lines showed enhanced growth ability under drought stress during which transgenic lines had increased the relative water content, leaf water potential, relative average growth rate, but decreased the malondialdehyde content compared with the non-transgenic plant. Thus, transgenic breeding is an efficient approach to enhance drought tolerance in L. chinensis.

  10. Single molecule Raman spectroscopic assay to detect transgene from GM plants.

    Science.gov (United States)

    Kadam, Ulhas S; Chavhan, Rahul L; Schulz, Burkhard; Irudayaraj, Joseph

    2017-09-01

    Substantial concerns have been raised for the safety of transgenics on human health and environment. Many organizations, consumer groups, and environmental agencies advocate for stringent regulations to avoid transgene products' contamination in food cycle or in nature. Here we demonstrate a novel approach using surface enhanced Raman spectroscopy (SERS) to detect and quantify transgene from GM plants. We show a highly sensitive and accurate quantification of transgene DNA from multiple transgenic lines of Arabidopsis. The assay allows us to detect and quantify the transgenes as low as 0.10 pg without need for PCR-amplification. This technology is relatively cheap, quick, simple, and suitable for detection at low target concentration. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Incipient resistance of Helicoverpa punctigera to the Cry2Ab Bt toxin in Bollgard II cotton.

    Directory of Open Access Journals (Sweden)

    Sharon Downes

    Full Text Available Combinations of dissimilar insecticidal proteins ("pyramids" within transgenic plants are predicted to delay the evolution of pest resistance for significantly longer than crops expressing a single transgene. Field-evolved resistance to Bacillus thuringiensis (Bt transgenic crops has been reported for first generation, single-toxin varieties and the Cry1 class of proteins. Our five year data set shows a significant exponential increase in the frequency of alleles conferring Cry2Ab resistance in Australian field populations of Helicoverpa punctigera since the adoption of a second generation, two-toxin Bt cotton expressing this insecticidal protein. Furthermore, the frequency of cry2Ab resistance alleles in populations from cropping areas is 8-fold higher than that found for populations from non-cropping regions. This report of field evolved resistance to a protein in a dual-toxin Bt-crop has precisely fulfilled the intended function of monitoring for resistance; namely, to provide an early warning of increases in frequencies that may lead to potential failures of the transgenic technology. Furthermore, it demonstrates that pyramids are not 'bullet proof' and that rapid evolution to Bt toxins in the Cry2 class is possible.

  12. Quantification of Bt δ-endotoxins in leaf tissues of tropical Bt maize ...

    African Journals Online (AJOL)

    Murenga Mwimali

    2012-06-26

    Jun 26, 2012 ... In Kenya, stem borers destroy an estimated 13.5% of farmers' annual maize harvest. Maize transformed using Bacillus thuringiensis (Bt) derived genes controls stem borers without negative effects to humans, livestock or the environment. The effectiveness and sustainability of Bt transgenic technology.

  13. Evaluation of transgenic soybean exhibiting high expression of a synthetic Bacillus thuringiensis cry1A transgene for suppressing lepidopteran population densities and crop injury.

    Science.gov (United States)

    McPherson, Robert M; MacRae, Ted C

    2009-08-01

    Several transgenic lines of soybean, Glycine max (L.) Merr., expressing a synthetic cry1A gene from Bacillus thuringiensis (Bt), were examined in replicated field trials in 2003-2007 for suppression of naturally occurring population densities of lepidopteran pests and the resultant crop injury that they caused. Bt soybean and negative controls (isogenic segregants and parental lines) were evaluated against velvetbean caterpillar, Anticarsia gemmatalis (Hübner); soybean looper, Pseudoplusia includens (Walker); and green cloverworm, Hypena scabra (F.). Population densities of these lepidopteran species were essentially absent in each of the Bt soybean entries evaluated throughout the growing season in every year of the study compared with moderate (5-10 larvae per row-m) to large (20-30 larvae per row-m) peak population densities in the negative control soybean entries. These lepidopteran populations caused significant plant injury in the non-Bt soybean plots, ranging from 53% defoliation in 2003 to 17.5% in 2007, compared with < 1.5% defoliation (mostly 0.0% defoliation) in the Bt soybean plots. When two or three foliar insecticides were applied in August or September, as lepidopteran populations approached or exceeded economic threshold levels, pest populations were suppressed and defoliation was minimal in the treated non-Bt entries similar to results in Bt soybean. Soybean 100-seed weights and harvested yields were similar between the Bt and non-Bt entries each year of this study. It seems that Bt transgenic soybean provides excellent season-long control of lepidopteran pests and have yields equal to the standard cultivars examined in this study. Once available to producers, this Bt technology has the potential to provide an effective insect pest management option similar to that being used in Bt cotton, Gossypium hirsutum L., and Bt corn, Zea mays L., and enhance the sustainability and profitability of soybean production in the southern region where

  14. 5-Azacytidine mediated reactivation of silenced transgenes in potato (Solanum tuberosum) at the whole plant level.

    Science.gov (United States)

    Tyč, Dimitrij; Nocarová, Eva; Sikorová, Lenka; Fischer, Lukáš

    2017-08-01

    Transient 5-azacytidine treatment of leaf explants from potato plants with transcriptionally silenced transgenes allows de novo regeneration of plants with restored transgene expression at the whole plant level. Transgenes introduced into plant genomes frequently become silenced either at the transcriptional or the posttranscriptional level. Transcriptional silencing is usually associated with DNA methylation in the promoter region. Treatments with inhibitors of maintenance DNA methylation were previously shown to allow reactivation of transcriptionally silenced transgenes in single cells or tissues, but not at the whole plant level. Here we analyzed the effect of DNA methylation inhibitor 5-azacytidine (AzaC) on the expression of two silenced reporter genes encoding green fluorescent protein (GFP) and neomycin phosphotransferase (NPTII) in potato plants. Whereas no obvious reactivation was observed in AzaC-treated stem cuttings, transient treatment of leaf segments with 10 μM AzaC and subsequent de novo regeneration of shoots on the selective medium with kanamycin resulted in the production of whole plants with clearly reactivated expression of previously silenced transgenes. Reactivation of nptII expression was accompanied by a decrease in cytosine methylation in the promoter region of the gene. Using the plants with reactivated GFP expression, we found that re-silencing of this transgene can be accidentally triggered by de novo regeneration. Thus, testing the incidence of transgene silencing during de novo regeneration could be a suitable procedure for negative selection of transgenic lines (insertion events) which have an inclination to be silenced. Based on our analysis of non-specific inhibitory effects of AzaC on growth of potato shoots in vitro, we estimated that AzaC half-life in the culture media is approximately 2 days.

  15. Isoprene emission protects photosynthesis but reduces plant productivity during drought in transgenic tobacco (Nicotiana tabacum) plants.

    Science.gov (United States)

    Ryan, Annette C; Hewitt, C Nicholas; Possell, Malcolm; Vickers, Claudia E; Purnell, Anna; Mullineaux, Philip M; Davies, William J; Dodd, Ian C

    2014-01-01

    Isoprene protects the photosynthetic apparatus of isoprene-emitting plants from oxidative stress. The role of isoprene in the response of plants to drought is less clear. Water was withheld from transgenic isoprene-emitting and non-emitting tobacco (Nicotiana tabacum) plants, to examine: the response of isoprene emission to plant water deficit; a possible relationship between concentrations of the drought-induced phytohormone abscisic acid (ABA) and isoprene; and whether isoprene affected foliar reactive oxygen species (ROS) and lipid peroxidation levels. Isoprene emission did not affect whole-plant water use, foliar ABA concentration or leaf water potential under water deficit. Compared with well-watered controls, droughted non-emitting plants significantly increased ROS content (31-46%) and lipid peroxidation (30-47%), concomitant with decreased operating and maximum efficiencies of photosystem II photochemistry and lower leaf and whole-plant water use efficiency (WUE). Droughted isoprene-emitting plants showed no increase in ROS content or lipid peroxidation relative to well-watered controls, despite isoprene emission decreasing before leaf wilting. Although isoprene emission protected the photosynthetic apparatus and enhanced leaf and whole-plant WUE, non-emitting plants had 8-24% more biomass under drought, implying that isoprene emission incurred a yield penalty. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  16. Loading and Light Degradation Characteristics of Bt Toxin on Nanogoethite: A Potential Material for Controlling the Environmental Risk of Bt Toxin

    Directory of Open Access Journals (Sweden)

    Xueyong Zhou

    2015-01-01

    Full Text Available Transgenic Bt-modified crops release toxins into soil through root exudates and upon decomposition of residues. The fate of these toxins in soil has not been yet clearly elucidated. Nanogoethite was found to have a different influence on the lifetime and insecticidal activity of Bt toxin. The aim of this study was to elucidate the adsorption characteristics of Bt toxin on nanogoethite and its activity changes before and after adsorption. The adsorption of toxin on nanogoethite reached equilibrium within 5 h, and the adsorption isotherm of Bt toxin on nanogoethite conformed to the Langmuir equation (R2>0.9690. In the range of pH from 6.0 to 8.0, larger adsorption occurred at lower pH value. The toxin adsorption decreased with the temperature between 10 and 50°C. The results of FTIR, XRD, and SEM indicated that toxin did not influence the structure of nanogoethite and the adsorption of toxin only on the surface of nanogoethite. The LC50 value for bound toxin was higher than that of free toxin, and the nanogoethite greatly accelerated the degradation of toxin by ultraviolet irradiation. The above results suggested that nanogoethite is a potential material for controlling the environmental risk of toxin released by Bt transgenic plants.

  17. Compositions and methods relating to transgenic plants and cellulosic ethanol production

    Science.gov (United States)

    Tien, Ming [State College, PA; Carlson, John [Port Matilda, PA; Liang, Haiying [Clemson, SC

    2012-04-24

    Transgenic lignocellulosic plants are provided according to embodiments of the present invention, the transgenic plants transformed with an expression cassette encoding a protein operably linked to a signal peptide which targets the protein to a cell wall of the transgenic plant, where at least 5% of the total amino acid residues of the protein are tyrosine, lysine, serine, threonine or cysteine. Methods of increasing lignin-protein bonds in a lignocellulosic plant are provided according to embodiments of the present invention which include expressing a recombinant nucleic acid in a lignocellulosic plant, the recombinant nucleic acid encoding a protein operably linked to a signal peptide which targets the protein to the cell wall of a plant, where at least 5% of the total amino acid residues of the protein are tyrosine, lysine, serine, threonine or cysteine.

  18. Compositions and methods relating to transgenic plants and cellulosic ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Tien, Ming; Carlson, John; Liang, Haiying

    2015-06-02

    Transgenic lignocellulosic plants are provided according to embodiments of the present invention, the transgenic plants transformed with an expression cassette encoding a protein operably linked to a signal peptide which targets the protein to a cell wall of the transgenic plant, where at least 5% of the total amino acid residues of the protein are tyrosine, lysine, serine, threonine or cysteine. Methods of increasing lignin-protein bonds in a lignocellulosic plant are provided according to embodiments of the present invention which include expressing a recombinant nucleic acid in a lignocellulosic plant, the recombinant nucleic acid encoding a protein operably linked to a signal peptide which targets the protein to the cell wall of a plant, where at least 5% of the total amino acid residues of the protein are tyrosine, lysine, serine, threonine or cysteine.

  19. Vast potential for using the piggyBac transposon to engineer transgenic plants

    Science.gov (United States)

    The acceptance of bioengineered plants by some nations is hampered by a number of factors, including the random insertion of a transgene into the host genome. Emerging technologies, such as site-specific nucleases, are enabling plant scientists to promote recombination or mutations at specific plant...

  20. Minimizing the unpredictability of transgene expression in plants: the role of genetic insulators

    Science.gov (United States)

    The genetic transformation of plants has become a necessary tool for fundamental plant biology research, as well as the generation of engineered plants exhibiting improved agronomic and industrial traits. However, this technology is significantly hindered by the fact that transgene expression is hi...

  1. Increasing of antioxidant and superoxide dismutase activity in chicory transgenic plants

    Directory of Open Access Journals (Sweden)

    Matvieieva N. A.

    2013-03-01

    Full Text Available Aim. Determination of the antioxidant activity (AOA and superoxide dismutase (SOD activity in transgenic chicory plants carrying the human interferon α2b target and nptII or bar selective genes. Methods. AOA was measured by a method based on the determination of kinetics of the reduced 2,6-dichlorophenolindophenol oxidation. SOD activity was assayed using the system consisting of ethionine, riboflavin, and nitroblue tetrazolium. Results. Antioxidant activity of transformed plants extracts was more than 1,91–2,59 and 2,04–2,43 times over the activity of control non-transgenic plants (at nptII and bar gene presence respectively. SOD activity was higher in transgenic plants than in the control, and was 2,03 ± 0,46–3,33 ± 0,54 U/g weight (nptII gene and 2,25 ± 0,46–2,68 ± 0,08 U/g weight (bar gene. Conclusions. Transgenic C. intybus plants have higher antioxidant and superoxide dismutase activity compared to non-transgenic plants. The increasing of AOA and SOD activity is a response of plants to transformation stress factor and integration of foreign genes in plant genome.

  2. The composite effect of transgenic plant volatiles for acquired immunity to herbivory caused by inter-plant communications.

    Directory of Open Access Journals (Sweden)

    Atsushi Muroi

    Full Text Available A blend of volatile organic compounds (VOCs emitted from plants induced by herbivory enables the priming of defensive responses in neighboring plants. These effects may provide insights useful for pest control achieved with transgenic-plant-emitted volatiles. We therefore investigated, under both laboratory and greenhouse conditions, the priming of defense responses in plants (lima bean and corn by exposing them to transgenic-plant-volatiles (VOCos including (E-β-ocimene, emitted from transgenic tobacco plants (NtOS2 that were constitutively overexpressing (E-β-ocimene synthase. When lima bean plants that had previously been placed downwind of NtOS2 in an open-flow tunnel were infested by spider mites, they were more defensive to spider mites and more attractive to predatory mites, in comparison to the infested plants that had been placed downwind of wild-type tobacco plants. This was similarly observed when the NtOS2-downwind maize plants were infested with Mythimna separata larvae, resulting in reduced larval growth and greater attraction of parasitic wasps (Cotesia kariyai. In a greenhouse experiment, we also found that lima bean plants (VOCos-receiver plants placed near NtOS2 were more attractive when damaged by spider mites, in comparison to the infested plants that had been placed near the wild-type plants. More intriguingly, VOCs emitted from infested VOCos-receiver plants affected their conspecific neighboring plants to prime indirect defenses in response to herbivory. Altogether, these data suggest that transgenic-plant-emitted volatiles can enhance the ability to prime indirect defenses via both plant-plant and plant-plant-plant communications.

  3. Bacillus species (BT42) isolated from Coffea arabica L. rhizosphere antagonizes Colletotrichum gloeosporioides and Fusarium oxysporum and also exhibits multiple plant growth promoting activity.

    Science.gov (United States)

    Kejela, Tekalign; Thakkar, Vasudev R; Thakor, Parth

    2016-11-18

    Colletotrichum and Fusarium species are among pathogenic fungi widely affecting Coffea arabica L., resulting in major yield loss. In the present study, we aimed to isolate bacteria from root rhizosphere of the same plant that is capable of antagonizing Colletotrichum gloeosporioides and Fusarium oxysporum as well as promotes plant growth. A total of 42 Bacillus species were isolated, one of the isolates named BT42 showed maximum radial mycelial growth inhibition against Colletotrichum gloeosporioides (78%) and Fusarium oxysporum (86%). BT42 increased germination of Coffee arabica L. seeds by 38.89%, decreased disease incidence due to infection of Colletotrichum gloeosporioides to 2.77% and due to infection of Fusarium oxysporum to 0 (p Colletotrichum gloeosporioides and Fusarium oxysporum. The mechanism of action of inhibition of the pathogenic fungi found to be synergistic effects of secondary metabolites, lytic enzymes, and siderophores. The major inhibitory secondary metabolite identified as harmine (β-carboline alkaloids).

  4. Stacking of antimicrobial genes in potato transgenic plants confers increased resistance to bacterial and fungal pathogens.

    Science.gov (United States)

    Rivero, Mercedes; Furman, Nicolás; Mencacci, Nicolás; Picca, Pablo; Toum, Laila; Lentz, Ezequiel; Bravo-Almonacid, Fernando; Mentaberry, Alejandro

    2012-01-20

    Solanum tuberosum plants were transformed with three genetic constructions expressing the Nicotiana tabacum AP24 osmotine, Phyllomedusa sauvagii dermaseptin and Gallus gallus lysozyme, and with a double-transgene construction expressing the AP24 and lysozyme sequences. Re-transformation of dermaseptin-transformed plants with the AP24/lysozyme construction allowed selection of plants simultaneously expressing the three transgenes. Potato lines expressing individual transgenes or double- and triple-transgene combinations were assayed for resistance to Erwinia carotovora using whole-plant and tuber infection assays. Resistance levels for both infection tests compared consistently for most potato lines and allowed selection of highly resistant phenotypes. Higher resistance levels were found in lines carrying the dermaseptin and lysozyme sequences, indicating that theses proteins are the major contributors to antibacterial activity. Similar results were obtained in tuber infection tests conducted with Streptomyces scabies. Plant lines showing the higher resistance to bacterial infections were challenged with Phytophthora infestans, Rhizoctonia solani and Fusarium solani. Considerable levels of resistance to each of these pathogens were evidenced employing semi-quantitative tests based in detached-leaf inoculation, fungal growth inhibition and in vitro plant inoculation. On the basis of these results, we propose that stacking of these transgenes is a promising approach to achieve resistance to both bacterial and fungal pathogens. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Rice Blast Resistance of Transgenic Rice Plants with Pi-d2 Gene

    Directory of Open Access Journals (Sweden)

    De-xi CHEN

    2010-09-01

    Full Text Available Resistance to rice blast of transgenic rice lines harboring rice blast resistance gene Pi-d2 transformed from three different expression vectors of pCB6.3kb, pCB5.3kb and pZH01-2.72kb were analyzed. Nine advanced-generation transgenic rice lines with Pi-d2 gene displayed various resistance to 39 rice blast strains, and the highest disease-resistant frequency reached 91.7%. Four early-generation homozygous transgenic lines with Pi-d2 gene exhibited resistance to more than 81.5% of 58 rice blast strains, showing the characteristic of wide-spectrum resistance. The transgenic embryonic calli selected by the crude toxin of rice blast fungus showed that the callus induction rate of immature embryo from transgenic rice plants decreased as the concentration of crude toxin in the culture medium increased. When the concentration of crude toxin reached 40%, the callus induction rate of immature embryo from transgenic lines was 49.3%, and that of the receptor control was 5%. The disease incidence of neck blast of the transgenic rice lines in fields under induction was 0% to 50%, indicating that the rice blast resistance of transgenic rice lines is much higher than that of the receptor control.

  6. Bt Sweet Corn: What Is It and Why Should We Use It?

    OpenAIRE

    Barlow, Vonny M.; Kuhar, Thomas Patrick, 1969-; Speese, John

    2009-01-01

    This publication reviews Transgenic Bt sweet corn hybrids which are a genetically modified organism (GMO) that are the result of combining commercially available sweet corn varieties with genes from a naturally occurring soil bacterium called Bacillus thuringiensis Berliner or Bt.

  7. Diversity of arthropod community in transgenic poplar-cotton ecosystems.

    Science.gov (United States)

    Zhang, D J; Lu, Z Y; Liu, J X; Li, C L; Yang, M S

    2015-12-02

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of plain cotton fields in China. Here, we performed a systematic survey of the diversity and population of arthropod communities in four different combination of poplar-cotton eco-systems, including I) non-transgenic poplar and non-transgenic cotton fields; II) non-transgenic poplar and transgenic cotton fields [Bacillus thuringiensis (Bt) cotton]; III) Bt transgenic poplar (high insect resistant strain Pb29) and non-transgenic cotton; and IV) transgenic poplar and transgenic cotton fields, over a period of 3 years. Based on the statistical methods used to investigate community ecology, the effects of transgenic ecosystems on the whole structure of the arthropod community, on the structure of arthropods in the nutritive layer, and on the similarity of arthropod communities were evaluated. The main results were as follows: the transgenic poplar-cotton ecosystem has a stronger inhibitory effect on insect pests and has no impact on the structure of the arthropod community, and therefore, maintains the diversity of the arthropod community. The character index of the community indicated that the structure of the arthropod community of the transgenic poplar-cotton ecosystem was better than that of the poplar-cotton ecosystem, and that system IV had the best structure. As for the abundance of nutritional classes, the transgenic poplar-cotton ecosystem was also better than that of the non-transgenic poplar-cotton ecosystem. The cluster analysis and similarity of arthropod communities between the four different transgenic poplar-cotton ecosystems illustrated that the structure of the arthropod community excelled in the small sample of the transgenic poplar-cotton ecosystems.

  8. Transgenic tomato plants expressing the antigen gene PfCP-2.9 of Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Mihail Kantor

    2013-01-01

    Full Text Available The objective of this work was to obtain transgenic tomato plants expressing the PfCP-2.9 protein (a chimera of the antigens MSP1 and AMA1 of Plasmodium falciparum. Cotyledons of seven-day-old tomatoes, cultivar Summers, were transformed via Agrobacterium tumefaciens. Transgenic expression in the T0 plants was verified in the DNA extracted from fruits. PCR analysis was used to test the presence of the gene of interest in the T1 generation. Reverse transcriptase PCR provided evidence of gene expression at the RNA level, and Western blot analysis confirmed the presence of the protein of interest in the T1 plants. This is the first report of successful transformation with the expression of a malaria antigen (PfCP-2.9 in transgenic tomato plants from the T0 and T1 generations.

  9. Microarray analyses reveal that plant mutagenesis may induce more transcriptomic changes than transgene insertion

    OpenAIRE

    Batista, Rita; Saibo, Nelson; Lourenço, Tiago; Oliveira, Maria Margarida

    2008-01-01

    Controversy regarding genetically modified (GM) plants and their potential impact on human health contrasts with the tacit acceptance of other plants that were also modified, but not considered as GM products (e.g., varieties raised through conventional breeding such as mutagenesis). What is beyond the phenotype of these improved plants? Should mutagenized plants be treated differently from transgenics? We have evaluated the extent of transcriptome modification occurring ...

  10. Analysis of promoter activity in transgenic plants by normalizing ...

    Indian Academy of Sciences (India)

    Variations in transgene expression due to position effect and copy number are normalized when analysing and comparing the strengths of different promoters. In such experiments, the promoter to be tested is placed upstream to a reporter gene and a second expression cassette is introduced in a linked fashion in the same ...

  11. Comparing Gene Expression Profiles Between Bt and non-Bt Rice in Response to Brown Planthopper Infestation.

    Science.gov (United States)

    Wang, Fang; Ning, Duo; Chen, Yang; Dang, Cong; Han, Nai-Shun; Liu, Yu'e; Ye, Gong-Yin

    2015-01-01

    Bt proteins are the most widely used insecticidal proteins in transgenic crops for improving insect resistance. We previously observed longer nymphal developmental duration and lower fecundity in brown planthopper (BPH) fed on Bt rice line KMD2, although Bt insecticidal protein Cry1Ab could rarely concentrate in this non-target rice pest. In the present study, we performed microarray analysis in an effort to detect Bt-independent variation, which might render Bt rice more defensive and/or less nutritious to BPH. We detected 3834 and 3273 differentially expressed probe-sets in response to BPH infestation in non-Bt parent Xiushui 11 and Bt rice KMD2, respectively, only 439 of which showed significant differences in expression between rice lines. Our analysis revealed a shift from growth to defense responses in response to BPH infestation, which was also detected in many other studies of plants suffering biotic and abiotic stresses. Chlorophyll biosynthesis and basic metabolism pathways were inhibited in response to infestation. IAA and GA levels decreased as a result of the repression of biosynthesis-related genes or the induction of inactivation-related genes. In accordance with these observations, a number of IAA-, GA-, BR-signaling genes were downregulated in response to BPH. Thus, the growth of rice plants under BPH attack was reduced and defense related hormone signaling like JA, SA and ET were activated. In addition, growth-related hormone signaling pathways, such as GA, BR, and auxin signaling pathways, as well as ABA, were also found to be involved in BPH-induced defense. On the other side, 51 probe-sets (represented 50 genes) that most likely contribute to the impact of Bt rice on BPH were identified, including three early nodulin genes, four lipid metabolic genes, 14 stress response genes, three TF genes and genes with other functions. Two transcription factor genes, bHLH and MYB, together with lipid transfer protein genes LTPL65 and early nodulin gene ENOD

  12. Comparing gene expression profiles between Bt and non-Bt rice in response to brown planthopper infestation

    Directory of Open Access Journals (Sweden)

    Fang eWang

    2015-12-01

    Full Text Available Bt proteins are the most widely used insecticidal proteins in transgenic crops for improving insect resistance. We previously observed longer nymphal developmental duration and lower fecundity in brown planthopper (BPH fed on Bt rice line KMD2, although Bt insecticidal protein Cry1Ab could rarely concentrate in this non-target rice pest. In the present study, we performed microarray analysis in an effort to detect Bt-independent variation, which might render Bt rice more defensive and/or less nutritious to BPH. We detected 3,834 and 3,273 differentially expressed probe-sets in response to BPH infestation in non-Bt parent Xiushui 11 and Bt rice KMD2, respectively, only 439 of which showed significant differences in expression between rice lines. Our analysis revealed a shift from growth to defense responses in response to BPH infestation, which was also detected in many other studies of plants suffering biotic and abiotic stresses. Chlorophyll biosynthesis and basic metabolism pathways were inhibited in response to infestation. IAA and GA levels decreased as a result of the repression of biosynthesis-related genes or the induction of inactivation-related genes. In accordance with these observations, a number of IAA-, GA-, BR-signaling genes were downregulated in response to BPH. Thus, the growth of rice plants under BPH attack was reduced and defense related hormone signaling like JA, SA and ET were activated. In addition, growth-related hormone signaling pathways, such as GA, BR and auxin signaling pathways, as well as ABA, were also found to be involved in BPH-induced defense. On the other side, 51 probe-sets (represented 50 genes that most likely contribute to the impact of Bt rice on BPH were identified, including three early nodulin genes, four lipid metabolic genes, 14 stress response genes, three TF genes and genes with other functions. Two transcription factor genes, bHLH and MYB, together with lipid transfer protein genes LTPL65 and

  13. Generation of transgenic plants of a potential oilseed crop Camelina sativa by Agrobacterium-mediated transformation.

    Science.gov (United States)

    Lu, Chaofu; Kang, Jinling

    2008-02-01

    Camelina sativa is an alternative oilseed crop that can be used as a potential low-cost biofuel crop or a source of health promoting omega-3 fatty acids. Currently, the fatty acid composition of camelina does not uniquely fit any particular uses, thus limit its commercial value and large-scale production. In order to improve oil quality and other agronomic characters, we have developed an efficient and simple in planta method to generate transgenic camelina plants. The method included Agrobacterium-mediated inoculation of plants at early flowering stage along with a vacuum infiltration procedure. We used a fluorescent protein (DsRed) as a visual selection marker, which allowed us to conveniently screen mature transgenic seeds from a large number of untransformed seeds. Using this method, over 1% of transgenic seeds can be obtained. Genetic analysis revealed that most of transgenic plants contain a single copy of transgene. In addition, we also demonstrated that transgenic camelina seeds produced novel hydroxy fatty acids by transforming a castor fatty acid hydroxylase. In conclusion, our results provide a rapid means to genetically improve agronomic characters of camelina, including fatty acid profiles of its seed oils. Camelina may serve as a potential industrial crop to produce novel biotechnology products.

  14. Recovery of amiRNA3-PARP1 transgenic maize plants using a ...

    African Journals Online (AJOL)

    Positive plant selectable marker genes are commonly used in plant transformation because they not only enhance the frequency of generation transgenic tissues but are considered biosafe, unlike antibiotic or herbicide resistance genes. In this study, the binary vector pNOV2819-ubiamiRNA3PARP1, harbouring the ...

  15. Generation of transgenic plants expressing antibodies to the environmental pollutant microcystin-LR.

    Science.gov (United States)

    Drake, Pascal M W; Barbi, Tommaso; Drever, Matthew R; van Dolleweerd, Craig J; Porter, Andrew J R; Ma, Julian K-C

    2010-03-01

    We describe the engineering, regeneration, and characterization of transgenic tobacco plants expressing a recombinant antibody specific to microcystin-LR (MC-LR), the environmental toxin pollutant produced by species of cyanobacteria. The antibody was created by a genetic fusion of the antigen-binding regions of the microcystin-specific single-chain antibody, 3A8, with constant regions from the murine IgG1kappa, Guy's 13. IgG transgenes were controlled by a leader peptide that targets the transgene products to the secretory pathway and also allows for rhizosecretion. The antibody, extracted from the leaves or rhizosecreted into hydroponic medium by transgenic plants, was shown to have functional binding to MC-LR. Antibody yields in transgenic plant leaves reached a maximum of 64 microg/g leaf fresh weight (0.6% total soluble protein), and the rate of antibody rhizosecretion reached a maximum of 5 microg/g root dry weight/24 h. Rhizosecreted antibody bound to MC-LR in hydroponic medium, and transgenic plants grew more efficiently on medium containing MC-LR compared to wild-type controls. This proof of concept paves the way for applications to produce diagnostic antibodies to microcystin-LR, remove it from the environment by phytoremediation, or enhance yields in crops exposed to MC-LR.-Drake, P. M. W., Barbi, T., Drever, M. R., van Dolleweerd, C. J., Porter, A. J. R., Ma, J. K.-C. Generation of transgenic plants expressing antibodies to the environmental pollutant microcystin-LR.

  16. Accurate measurement of transgene copy number in crop plants using droplet digital PCR.

    Science.gov (United States)

    Collier, Ray; Dasgupta, Kasturi; Xing, Yan-Ping; Hernandez, Bryan Tarape; Shao, Min; Rohozinski, Dominica; Kovak, Emma; Lin, Jeanie; de Oliveira, Maria Luiza P; Stover, Ed; McCue, Kent F; Harmon, Frank G; Blechl, Ann; Thomson, James G; Thilmony, Roger

    2017-06-01

    Genetic transformation is a powerful means for the improvement of crop plants, but requires labor- and resource-intensive methods. An efficient method for identifying single-copy transgene insertion events from a population of independent transgenic lines is desirable. Currently, transgene copy number is estimated by either Southern blot hybridization analyses or quantitative polymerase chain reaction (qPCR) experiments. Southern hybridization is a convincing and reliable method, but it also is expensive, time-consuming and often requires a large amount of genomic DNA and radioactively labeled probes. Alternatively, qPCR requires less DNA and is potentially simpler to perform, but its results can lack the accuracy and precision needed to confidently distinguish between one- and two-copy events in transgenic plants with large genomes. To address this need, we developed a droplet digital PCR-based method for transgene copy number measurement in an array of crops: rice, citrus, potato, maize, tomato and wheat. The method utilizes specific primers to amplify target transgenes, and endogenous reference genes in a single duplexed reaction containing thousands of droplets. Endpoint amplicon production in the droplets is detected and quantified using sequence-specific fluorescently labeled probes. The results demonstrate that this approach can generate confident copy number measurements in independent transgenic lines in these crop species. This method and the compendium of probes and primers will be a useful resource for the plant research community, enabling the simple and accurate determination of transgene copy number in these six important crop species. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  17. Field trials to evaluate effects of continuously planted transgenic insect-resistant cottons on soil invertebrates.

    Science.gov (United States)

    Li, Xiaogang; Liu, Biao; Wang, Xingxiang; Han, Zhengmin; Cui, Jinjie; Luo, Junyu

    2012-03-01

    Impacts on soil invertebrates are an important aspect of environmental risk assessment and post-release monitoring of transgenic insect-resistant plants. The purpose of this study was to research and survey the effects of transgenic insect-resistant cottons that had been planted over 10 years on the abundance and community structure of soil invertebrates under field conditions. During 3 consecutive years (2006-2008), eight common taxa (orders) of soil invertebrates belonging to the phylum Arthropoda were investigated in two different transgenic cotton fields and one non-transgenic cotton field (control). Each year, soil samples were taken at four different growth stages of cotton (seedling, budding, boll forming and boll opening). Animals were extracted from the samples using the improved Tullgren method, counted and determined to the order level. The diversity of the soil fauna communities in the different fields was compared using the Simpson's, Shannon's diversity indices and evenness index. The results showed a significant sampling time variation in the abundance of soil invertebrates monitored in the different fields. However, no difference in soil invertebrate abundance was found between the transgenic cotton fields and the control field. Both sampling time and cotton treatment had a significant effect on the Simpson's, Shannon's diversity indices and evenness index. They were higher in the transgenic fields than the control field at the growth stages of cotton. Long-term cultivation of transgenic insect-resistant cottons had no significant effect on the abundance of soil invertebrates. Collembola, Acarina and Araneae could act as the indicators of soil invertebrate in this region to monitor the environmental impacts of transgenic plants in the future. This journal is © The Royal Society of Chemistry 2012

  18. An Arabidopsis mitochondrial uncoupling protein confers tolerance to drought and salt stress in transgenic tobacco plants.

    Directory of Open Access Journals (Sweden)

    Kevin Begcy

    Full Text Available BACKGROUND: Plants are challenged by a large number of environmental stresses that reduce productivity and even cause death. Both chloroplasts and mitochondria produce reactive oxygen species under normal conditions; however, stress causes an imbalance in these species that leads to deviations from normal cellular conditions and a variety of toxic effects. Mitochondria have uncoupling proteins (UCPs that uncouple electron transport from ATP synthesis. There is evidence that UCPs play a role in alleviating stress caused by reactive oxygen species overproduction. However, direct evidence that UCPs protect plants from abiotic stress is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Tolerances to salt and water deficit were analyzed in transgenic tobacco plants that overexpress a UCP (AtUCP1 from Arabidopsis thaliana. Seeds of AtUCP1 transgenic lines germinated faster, and adult plants showed better responses to drought and salt stress than wild-type (WT plants. These phenotypes correlated with increased water retention and higher gas exchange parameters in transgenic plants that overexpress AtUCP1. WT plants exhibited increased respiration under stress, while transgenic plants were only slightly affected. Furthermore, the transgenic plants showed reduced accumulation of hydrogen peroxide in stressed leaves compared with WT plants. CONCLUSIONS/SIGNIFICANCE: Higher levels of AtUCP1 improved tolerance to multiple abiotic stresses, and this protection was correlated with lower oxidative stress. Our data support previous assumptions that UCPs reduce the imbalance of reactive oxygen species. Our data also suggest that UCPs may play a role in stomatal closure, which agrees with other evidence of a direct relationship between these proteins and photosynthesis. Manipulation of the UCP protein expression in mitochondria is a new avenue for crop improvement and may lead to crops with greater tolerance for challenging environmental conditions.

  19. An Arabidopsis Mitochondrial Uncoupling Protein Confers Tolerance to Drought and Salt Stress in Transgenic Tobacco Plants

    Science.gov (United States)

    Begcy, Kevin; Mariano, Eduardo D.; Mattiello, Lucia; Nunes, Alessandra V.; Mazzafera, Paulo; Maia, Ivan G.; Menossi, Marcelo

    2011-01-01

    Background Plants are challenged by a large number of environmental stresses that reduce productivity and even cause death. Both chloroplasts and mitochondria produce reactive oxygen species under normal conditions; however, stress causes an imbalance in these species that leads to deviations from normal cellular conditions and a variety of toxic effects. Mitochondria have uncoupling proteins (UCPs) that uncouple electron transport from ATP synthesis. There is evidence that UCPs play a role in alleviating stress caused by reactive oxygen species overproduction. However, direct evidence that UCPs protect plants from abiotic stress is lacking. Methodology/Principal Findings Tolerances to salt and water deficit were analyzed in transgenic tobacco plants that overexpress a UCP (AtUCP1) from Arabidopsis thaliana. Seeds of AtUCP1 transgenic lines germinated faster, and adult plants showed better responses to drought and salt stress than wild-type (WT) plants. These phenotypes correlated with increased water retention and higher gas exchange parameters in transgenic plants that overexpress AtUCP1. WT plants exhibited increased respiration under stress, while transgenic plants were only slightly affected. Furthermore, the transgenic plants showed reduced accumulation of hydrogen peroxide in stressed leaves compared with WT plants. Conclusions/Significance Higher levels of AtUCP1 improved tolerance to multiple abiotic stresses, and this protection was correlated with lower oxidative stress. Our data support previous assumptions that UCPs reduce the imbalance of reactive oxygen species. Our data also suggest that UCPs may play a role in stomatal closure, which agrees with other evidence of a direct relationship between these proteins and photosynthesis. Manipulation of the UCP protein expression in mitochondria is a new avenue for crop improvement and may lead to crops with greater tolerance for challenging environmental conditions. PMID:21912606

  20. Transgenic maize plants expressing the Totivirus antifungal protein, KP4, are highly resistant to corn smut.

    Science.gov (United States)

    Allen, Aron; Islamovic, Emir; Kaur, Jagdeep; Gold, Scott; Shah, Dilip; Smith, Thomas J

    2011-10-01

    The corn smut fungus, Ustilago maydis, is a global pathogen responsible for extensive agricultural losses. Control of corn smut using traditional breeding has met with limited success because natural resistance to U. maydis is organ specific and involves numerous maize genes. Here, we present a transgenic approach by constitutively expressing the Totivirus antifungal protein KP4, in maize. Transgenic maize plants expressed high levels of KP4 with no apparent negative impact on plant development and displayed robust resistance to U. maydis challenges to both the stem and ear tissues in the greenhouse. More broadly, these results demonstrate that a high level of organ independent fungal resistance can be afforded by transgenic expression of this family of antifungal proteins. © 2011 The Authors. Plant Biotechnology Journal © 2011 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  1. Alterations of Endogenous Cytokinins in Transgenic Plants Using a Chimeric Isopentenyl Transferase Gene.

    Science.gov (United States)

    Medford, J. I.; Horgan, R.; El-Sawi, Z.; Klee, H. J.

    1989-04-01

    Cytokinins, a class of phytohormones, appear to play an important role in the processes of plant development. We genetically engineered the Agrobacterium tumefaciens isopentenyl transferase gene, placing it under control of a heat-inducible promoter (maize hsp70). The chimeric hsp70 isopentenyl transferase gene was transferred to tobacco and Arabidopsis plants. Heat induction of transgenic plants caused the isopentenyl transferase mRNA to accumulate and increased the level of zeatin 52-fold, zeatin riboside 23-fold, and zeatin riboside 5[prime]-monophosphate twofold. At the control temperature zeatin riboside and zeatin riboside 5[prime]-monophosphate in transgenic plants accumulated to levels 3 and 7 times, respectively, over levels in wild-type plants. This uninduced cytokinin increase affected various aspects of development. In tobacco, these effects included release of axillary buds, reduced stem and leaf area, and an underdeveloped root system. In Arabidopsis, reduction of root growth was also found. However, neither tobacco nor Arabidopsis transgenic plants showed any differences relative to wild-type plants in time of flowering. Unexpectedly, heat induction of cytokinins in transgenic plants produced no changes beyond those seen in the uninduced state. The lack of effect from heat-induced increases could be a result of the transient increases in cytokinin levels, direct or indirect induction of negating factor(s), or lack of a corresponding level of competent cellular factors. Overall, the effects of the increased levels of endogenous cytokinins in non-heat-shocked transgenic plants seemed to be confined to aspects of growth rather than differentiation. Since no alterations in the programmed differentiation pattern were found with increased cytokinin levels, this process may be controlled by components other than absolute cytokinin levels.

  2. THE TRANSGENIC PLANTS – ADVANTAGES REGARDING THEIR CULTIVATION AND POTENTIALLY RISKS CONCERNING THE FOOD SAFETY

    Directory of Open Access Journals (Sweden)

    Dana PUSTA

    2009-06-01

    Full Text Available During the last decades the genetic modifi ed organisms (GMO have started to “conquer”, little by little our lives. The most widely used are the trangenic plants, because they have bigger productions and they are resistant to different pests. In the beginning, the spread of the transgenic plants was controlled, but today many countries cultivate genetic modifi ed plants without any control. Among these countries Romania is ahead, starting the cultivation of the transgenic plants in 1999, very soon after their obtaining. This paper outline the effect of the food consumption obtained from this plants which may determine different effects on human body. Also, because the genetic modifi ed plants have bigger productions than the normal ones and they are more resistant, the farmers are not encouraged to declare that they are using genetic modifi ed seeds. So, in that way, the consumer does not know what kind of food he consumes.

  3. [Transgenic, transplastomic and transient approaches for foreign gene expression in plants].

    Science.gov (United States)

    Kuchuk, N V

    2007-01-01

    The review represents the latest results of the experiments carried out at the Department of genetic engineering of the Institute of cell biology and genetic engineering of the National Academy of Sciences of Ukraine in the field of creation oftransgenic and transplastomic plants as well as the use of transient expression for production of recombinant proteins. The new approaches of promoterless gene expression in transgenic plants and construction of transplastomic plants using "clipboard" species are discussed.

  4. Caffeine biosynthesis and adenine metabolism in transgenic Coffea canephora plants with reduced expression of N-methyltransferase genes.

    Science.gov (United States)

    Ashihara, Hiroshi; Zheng, Xin-Qiang; Katahira, Riko; Morimoto, Masayuki; Ogita, Shinjiro; Sano, Hiroshi

    2006-05-01

    In anti-sense and RNA interference transgenic plants of Coffea canephora in which the expression of CaMXMT1 was suppressed, caffeine biosynthesis from [8-(14)C]adenine was investigated, together with the overall metabolism of [8-(14)C]adenine. Compared with wild type control plants, total purine alkaloid biosynthesis from adenine and conversion of theobromine to caffeine were both reduced in the transgenic plants. As found previously, [8-(14)C]adenine was metabolised to salvage products (nucleotides and RNA), to degradation products (ureides and CO(2)) and to purine alkaloids (theobromine and caffeine). In the transgenic plants, metabolism of [8-(14)C]adenine shifted from purine alkaloid synthesis to purine catabolism or salvage for nucleotides. HPLC analysis revealed a significantly reduced caffeine content in the transgenic plants. A small quantity (less than 20 nmol g(-1) fresh weight) of xanthosine had accumulated in at least one of the transgenic plants.

  5. Cloning and functional characterization of MusaVND1 using transgenic banana plants.

    Science.gov (United States)

    Negi, Sanjana; Tak, Himanshu; Ganapathi, T R

    2015-06-01

    Vascular related NAC (NAM, ATAF and CUC) domain-containing genes regulate secondary wall deposition and differentiation of xylem vessel elements. MusaVND1 is an ortholog of Arabidopsis VND1 and contains the highly conserved NAC domain. The expression of MusaVND1 is highest in developing corm and during lignification conditions, the increase in expression of MusaVND1 coincides with the expression of PAL, COMT and C4H genes. MusaVND1 encodes a nuclear localized protein as MusaVND1-GFP fusion protein gets localized to nucleus. Transient overexpression of MusaVND1 converts banana embryogenic cells to xylem vessel elements, with a final differentiation frequency of 33.54% at the end of tenth day. Transgenic banana plants overexpressing MusaVND1 showed stunted growth and were characterized by PCR and Southern blot analysis. Transgenic banana plants showed transdifferentiation of various types of cells into xylem vessel elements and ectopic deposition of lignin in cells of various plant organs such as leaf and corm. Tracheary element formation was seen in the cortical region of transgenic corm as well as in epidermal cells of leaves. Biochemical analysis indicates significantly higher levels of lignin and cellulose content in transgenic banana lines than control plants. MusaVND1 overexpressing transgenic banana plants showed elevated expression levels of genes involved in lignin and cellulose biosynthesis pathway. Further expression of different MYB transcription factors positively regulating secondary wall deposition was also up regulated in MusaVND1 transgenic lines.

  6. Phenotypic Characterization of Transgenic Miscanthus sinensis Plants Overexpressing Arabidopsis Phytochrome B

    Directory of Open Access Journals (Sweden)

    Ok-Jin Hwang

    2014-01-01

    Full Text Available Phytochromes are dimeric pigment proteins with reversible photochromism between red and far-red light-absorbing forms. They are photoreceptors that regulate various aspects of plant growth and development and have been used for biotechnological applications to improve agricultural performance of crops. Miscanthus species have been suggested as one of the most promising energy crops. In this paper, Arabidopsis phytochrome B (PHYB gene was introduced into Miscanthus sinensis using Agrobacterium-mediated transformation method that we developed recently, with the herbicide resistance gene (BAR as a selection marker. After putative transgenic plants were selected using the herbicide resistance assay, genomic integration of the transgene was confirmed by genomic PCR and Southern blot analysis, and transgene expression was validated by Northern blot analysis. Compared to nontransformed control plants, transgenic plants overexpressing PHYB showed phenotypes with increased phytochrome B function, which includes increased chlorophyll content, decreased plant height, and delayed flowering. Therefore, these results suggest that Arabidopsis phytochrome B is functional in M. sinensis and provide a method to develop Miscanthus varieties with enhanced agricultural performance using phytochromes.

  7. Expression of kenaf mitochondrial chimeric genes HM184 causes male sterility in transgenic tobacco plants.

    Science.gov (United States)

    Zhao, Yanhong; Liao, Xiaofang; Huang, Zhipeng; Chen, Peng; Zhou, Bujin; Liu, Dongmei; Kong, Xiangjun; Zhou, Ruiyang

    2015-08-01

    Chimeric genes resulting from the rearrangement of a mitochondrial genome were generally thought to be a causal factor in the occurrence of cytoplasmic male sterility (CMS). In the study, earlier we reported that identifying a 47 bp deletion at 3'- flanking of atp9 that was linked to male sterile cytoplasm in kenaf. The truncated fragment was fused with atp9, a mitochondrial transit signal (MTS) and/or GFP, comprised two chimeric genes MTS-HM184-GFP and MTS-HM184. The plant expression vector pBI121 containing chimeric genes were then introduced to tobacco plants by Agrobacterium-mediated T-DNA transformation. The result showed that certain transgenic plants were male sterility or semi-sterility, while some were not. The expression analysis further demonstrated that higher level of expression were showed in the sterility plants, while no expression or less expression in fertility plants, the levels of expression of semi-sterility were in between. And the sterile plant (containing MTS-HM184-GFP) had abnormal anther produced malformed/shriveled pollen grains stained negative that failed to germinate (0%), the corresponding fruits was shrunken, the semi-sterile plants having normal anther shape produced about 10-50% normal pollen grains, the corresponding fruits were not full, and the germination rate was 58%. Meanwhile these transgenic plants which altered on fertility were further analyzed in phenotype. As a result, the metamorphosis leaves were observed in the seedling stage, the plant height of transgenic plants was shorter than wild type. The growth duration of transgenic tobacco was delayed 30-45 days compared to the wild type. The copy numbers of target genes of transgenic tobacco were analyzed using the real-time quantitative method. The results showed that these transgenic plants targeting-expression in mitochondrial containing MTS-HM184-GFP had 1 copy and 2 copies, the other two plants containing MTS-HM184 both had 3 copies, but 0 copy in wild type. In

  8. Transgenic tobacco plants having a higher level of methionine are more sensitive to oxidative stress.

    Science.gov (United States)

    Hacham, Yael; Matityahu, Ifat; Amir, Rachel

    2017-07-01

    Methionine is an essential amino acid the low level of which limits the nutritional quality of plants. We formerly produced transgenic tobacco (Nicotiana tabacum) plants overexpressing CYSTATHIONE γ-SYNTHASE (CGS) (FA plants), methionine's main regulatory enzyme. These plants accumulate significantly higher levels of methionine compared with wild-type (WT) plants. The aim of this study was to gain more knowledge about the effect of higher methionine content on the metabolic profile of vegetative tissue and on the morphological and physiological phenotypes. FA plants exhibit slightly reduced growth, and metabolic profiling analysis shows that they have higher contents of stress-related metabolites. Despite this, FA plants were more sensitive to short- and long-term oxidative stresses. In addition, compared with WT plants and transgenic plants expressing an empty vector, the primary metabolic profile of FA was altered less during oxidative stress. Based on morphological and metabolic phenotypes, we strongly proposed that FA plants having higher levels of methionine suffer from stress under non-stress conditions. This might be one of the reasons for their lesser ability to cope with oxidative stress when it appeared. The observation that their metabolic profiling is much less responsive to stress compared with control plants indicates that the delta changes in metabolite contents between non-stress and stress conditions is important for enabling the plants to cope with stress conditions. © 2017 Scandinavian Plant Physiology Society.

  9. Transgenic plants as green factories for vaccine production

    African Journals Online (AJOL)

    sunny t

    2013-10-23

    Oct 23, 2013 ... plant plateforms have been demonstrated for production of recombinant proteins in plants, including leafy crops, cereals and legume seeds, oil seeds, fruits, vegetables, higher plant tissue and cell cultures, hydroponic systems, algae and halobios (reviewed by Mei et al., 2006). Co- expression of adjuvant ...

  10. Design and construction of an in-plant activation cassette for transgene expression and recombinant protein production in plants.

    Science.gov (United States)

    Dugdale, Benjamin; Mortimer, Cara L; Kato, Maiko; James, Tess A; Harding, Robert M; Dale, James L

    2014-05-01

    Virus-based transgene expression systems have become particularly valuable for recombinant protein production in plants. The dual-module in-plant activation (INPACT) expression platform consists of a uniquely designed split-gene cassette incorporating the cis replication elements of Tobacco yellow dwarf geminivirus (TYDV) and an ethanol-inducible activation cassette encoding the TYDV Rep and RepA replication-associated proteins. The INPACT system is essentially tailored for recombinant protein production in stably transformed plants and provides both inducible and high-level transient transgene expression with the potential to be adapted to diverse crop species. The construction of a novel split-gene cassette, the inducible nature of the system and the ability to amplify transgene expression via rolling-circle replication differentiates this system from other DNA- and RNA-based virus vector systems used for stable or transient recombinant protein production in plants. Here we provide a detailed protocol describing the design and construction of a split-gene INPACT cassette, and we highlight factors that may influence optimal activation and amplification of gene expression in transgenic plants. By using Nicotiana tabacum, the protocol takes 6-9 months to complete, and recombinant proteins expressed using INPACT can accumulate to up to 10% of the leaf total soluble protein.

  11. Trichogramma (Hymenoptera: Trichogrammatidae) ecology in a tropical bt transgenic cotton cropping system: sampling to improve seasonal pest impact estimates in the Ord River Irrigation Area, Australia.

    Science.gov (United States)

    Davies, A P; Pufke, U S; Zalucki, M P

    2009-06-01

    Trichogramma Westwood (Hymenoptera: Trichogrammatidae) cause high mortality rates in the potentially resistant pest species, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), and are considered integral to the resistance management plan for Bacillus thuringiensis transgenic cotton, Gossypium hirsutum L., production in the Ord River Irrigation Area (ORIA), Western Australia. Measured as percentage of parasitism, Trichogramma activity seems highly variable over time; yet, it contributes significantly to pest suppression at peak insect pest density. Environmental constraints on Trichogramma survival, especially insecticide applications, may limit their effectiveness. The decision to initiate insecticide applications in ORIA cotton crops is best delayed unless absolutely necessary to avoid disruption of Trichogramma impact on pests. Trichogramma disperse into young crops and display high intrinsic rates of increase effectively stifling Helicoverpa (Hardwick) population increase after initial egg lay during high-density years in the ORIA, and evidence suggests a possible preference for H. armigera host eggs.

  12. Considerations for extraction of monoclonal antibodies targeted to different subcellular compartments in transgenic tobacco plants.

    Science.gov (United States)

    Hassan, Sally; van Dolleweerd, Craig J; Ioakeimidis, Fotis; Keshavarz-Moore, Eli; Ma, Julian K-C

    2008-09-01

    Monoclonal antibody production from transgenic tobacco plants offers many advantages over other heterologous production systems, creating the prospect of production at a scale that will allow new prophylactic and therapeutic applications in global human and animal health. However, information on the major processing factors to consider for large-scale purification of antibodies from transgenic plants is currently limited, and is in urgent need of attention. The purpose of this project was to investigate methods for the initial extraction of recombinant immunoglobulin G (IgG) antibodies from transgenic tobacco leaf tissue. Three different transgenic plant lines were studied in order to establish the parameters for optimal extraction of monoclonal antibodies that accumulate in the apoplasm, at the plasma membrane or within the endoplasmic reticulum. For each transgenic line, seven techniques for physical extraction were compared. The factors that determine the optimal extraction of antibodies from plants have a direct influence on the initial choice of expression strategy, and so must be considered at an early stage. The use of small-scale techniques that are applicable to large-scale purification was a particularly important consideration. The optimal extraction technique varied with the target location of IgG in the plant cell, and the dependence of antibody yield on the physical extraction methodology employed, the pH of the extraction buffer and the extraction temperature was demonstrated in each case. The addition of detergent to the extraction buffer may improve the yield, but this was found to be dependent on the site of accumulation of IgG within the plant cell.

  13. Occurence of Cucumber Mosaic Virus in Ornamental Plants and Perspectives of Transgenic Control

    NARCIS (Netherlands)

    Chen, Y.K.

    2003-01-01

    This thesis described the characterization of a range of ornamental-infecting Cucumber mosaic virus strains and the development of novel transgene constructs to improve the efficiency of obtaining resistant transformants which is essential for most ornamental plants that are

  14. Suppression of an atypically spliced rice CACTA transposon transcript in transgenic plants

    NARCIS (Netherlands)

    Greco, R.; Ouwerkerk, P.B.F.; Pereira, A.B.

    2005-01-01

    OsES1, a rice homolog of the maize En/Spm transposon, is transcribed to produce TnpA-like and TnpD-like transcripts. However, an alternatively spliced form of the TnpA-like transcript., which was found to be suppressed in transgenic plants, was revealed to be clue to atypical splicing of a Hipa-like

  15. Characterization of the Ac/Ds behaviour in transgenic tomato plants using plasmid rescue

    NARCIS (Netherlands)

    Rommens, Caius M.T.; Rudenko, George N.; Dijkwel, Paul P.; Haaren, Mark J.J. van; Ouwerkerk, Pieter B.F.; Blok, Karin M.; Nijkamp, H. John J.; Hille, Jacques

    1992-01-01

    We describe the use of plasmid rescue to facilitate studies on the behaviour of Ds and Ac elements in transgenic tomato plants. The rescue of Ds elements relies on the presence of a plasmid origin of replication and a marker gene selective in Escherichia coli within the element. The position within

  16. TRANSGENIC PLANTS OF RAPE (BRASSICA NAPUS L. WITH GENE OSMYB4 HAVE INCREASED RESISTANCE TO SALTS OF HEAVY METALS

    Directory of Open Access Journals (Sweden)

    Raldugina G.N.

    2012-08-01

    Full Text Available This work aims to study the response of the transgenic spring rape plants (Brassica napus L. var. ‘Westar’ with the rice transfactor-encoding gene Osmyb4 to treatment with salts of heavy metals (HM CuSO4 or ZnSO4 and accumulation in the leaves of biomass, metals, photosynthetic pigments, lipid peroxidation, and antioxidant compounds: total phenols, anthocyanins, and antioxidant enzyme activity superoxide dismutase (SOD and guaiacol peroxidase (POX were determined. Vegetatively propagated transgenic plants and wild-type plants were grown on Hoagland-Snyder medium at 24°C, then at the 5-6th leaves-stage, CuSO4 (in concentration 25-150 mM or ZnSO4 (500 - 5000 mM were added to the growth medium, and plants were exposed to the salts for 15 days. Under the action of small concentrations of salts, the results obtained for the transgenic and untransformed plants did not differ, but at high concentrations strong differences between transgenic and untransformed plants were observed. In transgenic plants, accumulation of biomass was greater. Carotene and xanthophyll were destroyed in transgenic plants less than in the untransformed plants. They have accumulated in their leaves more metal, especially Zn, reaching almost to the accumulation of 7 mg per g of dry biomass, bringing these plants to the hyperaccumulation of Zn. In the tissues of transgenic plants exposed to high concentrations of salts, the content of total phenols, anthocyanins, and low molecular weight compounds, that are responsible for protection against ROS, increased significantly. All these results indicate a greater stability of the transgenic plants to the action of heavy metals, as evidenced also by less activity of lipid peroxidases in their tissue: at high salt concentrations, malondialdehyde (MDA accumulated significantly less in transgenic plants than in non-transformed plant tissues. The greater stability of transgenic plants to stressful effect of HM is also evidenced by the

  17. A bioinformatics approach for identifying transgene insertion sites using whole genome sequencing data.

    Science.gov (United States)

    Park, Doori; Park, Su-Hyun; Ban, Yong Wook; Kim, Youn Shic; Park, Kyoung-Cheul; Kim, Nam-Soo; Kim, Ju-Kon; Choi, Ik-Young

    2017-08-15

    Genetically modified crops (GM crops) have been developed to improve the agricultural traits of modern crop cultivars. Safety assessments of GM crops are of paramount importance in research at developmental stages and before releasing transgenic plants into the marketplace. Sequencing technology is developing rapidly, with higher output and labor efficiencies, and will eventually replace existing methods for the molecular characterization of genetically modified organisms. To detect the transgenic insertion locations in the three GM rice gnomes, Illumina sequencing reads are mapped and classified to the rice genome and plasmid sequence. The both mapped reads are classified to characterize the junction site between plant and transgene sequence by sequence alignment. Herein, we present a next generation sequencing (NGS)-based molecular characterization method, using transgenic rice plants SNU-Bt9-5, SNU-Bt9-30, and SNU-Bt9-109. Specifically, using bioinformatics tools, we detected the precise insertion locations and copy numbers of transfer DNA, genetic rearrangements, and the absence of backbone sequences, which were equivalent to results obtained from Southern blot analyses. NGS methods have been suggested as an effective means of characterizing and detecting transgenic insertion locations in genomes. Our results demonstrate the use of a combination of NGS technology and bioinformatics approaches that offers cost- and time-effective methods for assessing the safety of transgenic plants.

  18. Risk assessment and ecological effects of transgenic Bacillus thuringiensis crops on non-target organisms.

    Science.gov (United States)

    Yu, Hui-Lin; Li, Yun-He; Wu, Kong-Ming

    2011-07-01

    The application of recombinant DNA technology has resulted in many insect-resistant varieties by genetic engineering (GE). Crops expressing Cry toxins derived from Bacillus thuringiensis (Bt) have been planted worldwide, and are an effective tool for pest control. However, one ecological concern regarding the potential effects of insect-resistant GE plants on non-target organisms (NTOs) has been continually debated. In the present study, we briefly summarize the data regarding the development and commercial use of transgenic Bt varieties, elaborate on the procedure and methods for assessing the non-target effects of insect-resistant GE plants, and synthetically analyze the related research results, mostly those published between 2005 and 2010. A mass of laboratory and field studies have shown that the currently available Bt crops have no direct detrimental effects on NTOs due to their narrow spectrum of activity, and Bt crops are increasing the abundance of some beneficial insects and improving the natural control of specific pests. The use of Bt crops, such as Bt maize and Bt cotton, results in significant reductions of insecticide application and clear benefits on the environment and farmer health. Consequently, Bt crops can be a useful component of integrated pest management systems to protect the crop from targeted pests. © 2011 Institute of Botany, Chinese Academy of Sciences.

  19. Leaf tissue assay for lepidopteran pests of Bt cotton

    Science.gov (United States)

    Laboratory measurements of susceptibility to Bt toxins can be a poor indicator of the ability of an insect to survive on transgenic crops. We investigated the potential of using cotton leaf tissue for evaluating heliothine susceptibilities to two dual-gene Bt cottons. A preliminary study was conduct...

  20. Production of vaccines for treatment of infectious diseases by transgenic plants

    Directory of Open Access Journals (Sweden)

    Kristina LEDL

    2016-04-01

    Full Text Available Since the first pathogen antigen was expressed in transgenic plants with the aim of producing edible vaccine in early 1990s, transgenic plants have become a well-established expression system for production of alternative vaccines against various human and animal infectious diseases. The main focus of plant expression systems in the last five years has been on improving expression of well-studied antigens such as porcine reproductive and respiratory syndrome (PRRSV, bovine viral diarrhea disease virus (BVDV, footh and mouth disease virus (FMDV, hepatitis B surface antigen (HBsAg, rabies G protein, rotavirus, Newcastle disease virus (NDV, Norwalk virus capsid protein (NVCP, avian influenza virus H5N1, Escherichia coli heat-labile enterotoxin subunit B (LT-B, cholera toxin B (CT-B, human immunodeficiency virus (HIV, artherosclerosis, ebola and anthrax. Significant increases in expression have been obtained using improved expression vectors, different plant species and transformation methods.

  1. Cre/lox-mediated marker gene excision in transgenic maize (Zea mays L.) plants.

    Science.gov (United States)

    Zhang, W; Subbarao, S; Addae, P; Shen, A; Armstrong, C; Peschke, V; Gilbertson, L

    2003-11-01

    After the initial transformation and tissue culture process is complete, selectable marker genes, which are used in virtually all transformation approaches, are not required for the expression of the gene of interest in the transgenic plants. There are several advantages to removing the selectable marker gene after it is no longer needed, such as enabling the reuse of selectable markers and simplifying transgene arrays. We have tested the Cre/ lox system from bacteriophage P1 for its ability to precisely excise stably integrated marker genes from chromosomes in transgenic maize plants. Two strategies, crossing and autoexcision, have been tested and demonstrated. In the crossing strategy, plants expressing the Cre recombinase are crossed with plants bearing a transgene construct in which the selectable marker gene is flanked by directly repeated lox sites. Unlike previous reports in which incomplete somatic and germline excision were common, in our experiments complete somatic and germline marker gene excision occurred in the F(1) plants from most crosses with multiple independent Cre and lox lines. In the autoexcision strategy, the cre gene, under the control of a heat shock-inducible promoter, is excised along with the nptII marker gene. Our results show that a transient heat shock treatment of primary transgenic callus is sufficient for inducing cre and excising the cre and nptII genes. Genetic segregation and molecular analysis confirmed that marker gene removal is precise, complete and stable. The autoexcision strategy provides a way of removing the selectable marker gene from callus or other tissues such as embryos and kernels.

  2. Expression of chimeric HCV peptide in transgenic tobacco plants ...

    African Journals Online (AJOL)

    Using plant-virus based transient expression to produce this unique chimeric antigen will facilitate the development and production of an experimental HCV vaccine. A plant derived recombinant HCV vaccine can potentially reduce expenses normally associated with production and delivery of conventional vaccine.

  3. Degradation of β-Aryl Ether Bonds in Transgenic Plants

    DEFF Research Database (Denmark)

    Mnich, Ewelina

    Lignin is one of the main building blocks of the plant cell wall. It tethers the cell wall by cross-linking with polysaccharides conferring mechanical strength to plants, aiding water transport and providing a mechanical barrier against pathogens. It is generated by the polymerization of the mono...

  4. Oral Vaccination Against Anthrax Using a Transgenic Plant Expressing Protective Antigen.

    Science.gov (United States)

    1996-09-01

    34 Anal. Biochem. 169:227-223. 10. Gould, J., M. Devey, 0. Hasegawa, E.C. Ulian, G. Peterson, and R.H. Smith (1991) "Transformation of Zea mays L. using...Against Anthrax Using a Transgenic Plant Expressing Protective Antigen PRINCIPAL INVESTIGATOR: Dr. Karen K. Oishi CONTRACTING ORGANIZATION: CropTech/Vet...COVERED I September 1996 Final - Phase I, 15 Auxg 95-14 Aug 96 4. TITLE AND 9UBTITLE 5. FUNDING NUMBERS Oral Vaccination Against Anthrax Using a Transgenic

  5. Transgenic expression of plant chitinases to enhance disease resistance.

    Science.gov (United States)

    Cletus, Jean; Balasubramanian, Vaiyapuri; Vashisht, Divya; Sakthivel, Natarajan

    2013-11-01

    Crop plants have evolved an array of mechanisms to counter biotic and abiotic stresses. Many pathogenesis-related proteins are expressed by plants during the attack of pathogens. Advances in recombinant DNA technology and understanding of plant-microbe interactions at the molecular level have paved the way for isolation and characterization of genes encoding such proteins, including chitinases. Chitinases are included in families 18 and 19 of glycosyl hydrolases (according to www.cazy.org ) and they are further categorized into seven major classes based on their aminoacid sequence homology, three-dimensional structures, and hydrolytic mechanisms of catalytic reactions. Although chitin is not a component of plant cell walls, plant chitinases are involved in development and non-specific stress responses. Also, chitinase genes sourced from plants have been successfully over-expressed in crop plants to combat fungal pathogens. Crops such as tomato, potato, maize, groundnut, mustard, finger millet, cotton, lychee, banana, grape, wheat and rice have been successfully engineered for fungal resistance either with chitinase alone or in combination with other PR proteins.

  6. Function and anatomy of plant siRNA pools derived from hairpin transgenes

    Directory of Open Access Journals (Sweden)

    Lee Kevin AW

    2007-11-01

    Full Text Available Abstract Background RNA interference results in specific gene silencing by small-interfering RNAs (siRNAs. Synthetic siRNAs provide a powerful tool for manipulating gene expression but high cost suggests that novel siRNA production methods are desirable. Strong evolutionary conservation of siRNA structure suggested that siRNAs will retain cross-species function and that transgenic plants expressing heterologous siRNAs might serve as useful siRNA bioreactors. Here we report a detailed evaluation of the above proposition and present evidence regarding structural features of siRNAs extracted from plants. Results Testing the gene silencing capacity of plant-derived siRNAs in mammalian cells proved to be very challenging and required partial siRNA purification and design of a highly sensitive assay. Using the above assay we found that plant-derived siRNAs are ineffective for gene silencing in mammalian cells. Plant-derived siRNAs are almost exclusively double-stranded and most likely comprise a mixture of bona fide siRNAs and aberrant partially complementary duplexes. We also provide indirect evidence that plant-derived siRNAs may contain a hitherto undetected physiological modification, distinct from 3' terminal 2-O-methylation. Conclusion siRNAs produced from plant hairpin transgenes and extracted from plants are ineffective for gene silencing in mammalian cells. Thus our findings establish that a previous claim that transgenic plants offer a cost-effective, scalable and sustainable source of siRNAs is unwarranted. Our results also indicate that the presence of aberrant siRNA duplexes and possibly a plant-specific siRNA modification, compromises the gene silencing capacity of plant-derived siRNAs in mammalian cells.

  7. Ribozyme genes protecting transgenic melon plants against potyviruses

    National Research Council Canada - National Science Library

    Huttner, E; Tucker, W; Vermeulen, A; Ignart, F; Sawyer, B; Birch, R

    2001-01-01

    Potyviruses are the most important viral pathogens of crops worldwide. Under a contract with Gene Shears Pty Limited, we are using ribozyme genes to protect melon plants against two potyviruses: WMV2 and ZYMV...

  8. Assessment of Populus wood chemistry following the introduction of a Bt toxin gene

    Energy Technology Data Exchange (ETDEWEB)

    Tschaplinski, Timothy J [ORNL; Davis, M F [National Energy Renewable Laboratory; Tuskan, Gerald A [ORNL; Payne, M M [Boise Cascade LLC; Meilan, R [Purdue University

    2006-01-01

    Unintended changes in plant physiology, anatomy and metabolism as a result of genetic engineering are a concern as more transgenic plants are commercially deployed in the ecosystem. We compared the cell wall chemical composition of three Populus lines (Populus trichocarpa Torr. & A. Gray x Populus trichocarpa Bartr. ex Marsh., Populus trichocarpa x Populus nigra L. and Populus deltoides x Populus nigra) genetically modified to express the Cry3A or Cry3B2 protein of Bacillus thuringiensis (Bt) with the cell wall chemistry of non-transformed isogenic control lines. Three genetically modified clones, each represented by 10 independent transgenic lines, were analyzed by pyrolysis molecular beam mass spectrometry, gas chromatography/mass spectrometry and traditional wet chemical analytical methods to assess changes in cell wall composition. Based on the outcome of these techniques, there were no comprehensive differences in chemical composition between the transgenic and control lines for any of the studied clones.

  9. Assessment of Populus Wood Chemistry Following the Introduction of a Bt Toxin Gene

    Energy Technology Data Exchange (ETDEWEB)

    Davis, M. F.; Tuskan, G. A.; Payne, P.; Tschaplinski, T. J.; Meilan, R.

    2006-01-01

    Unintended changes in plant physiology, anatomy and metabolism as a result of genetic engineering are a concern as more transgenic plants are commercially deployed in the ecosystem. We compared the cell wall chemical composition of three Populus lines (Populus trichocarpa Torr. and A. Gray x Populus deltoides Bartr. ex Marsh., Populus trichocarpa x Populus nigra L. and Populus deltoides x Populus nigra) genetically modified to express the Cry3A or Cry3B2 protein of Bacillus thuringiensis (Bt) with the cellwall chemistry of non-transformed isogenic control lines. Three genetically modified clones, each represented by 10 independent transgenic lines, were analyzed by pyrolysis molecular beam mass spectrometry, gas chromatography/mass spectrometry and traditional wet chemical analytical methods to assess changes in cell wall composition. Based on the outcome of these techniques, there were no comprehensive differences in chemical composition between the transgenic and control lines for any of the studied clones.

  10. Does Bt rice pose risks to non-target arthropods? Results of a meta-analysis in China

    Science.gov (United States)

    Transgenic Bt rice expressing the protoxin proteins derived from Bacillus thuringiensis Berliner (Bt) have been developed since 1989. Their ecological risks toward non-target organisms have been investigated. However, these studies were conducted individually, yielding inconsistent conclusions and u...

  11. Vast potential for using the piggyBac transposon to engineer transgenic plants at specific genomic locations

    OpenAIRE

    Johnson, Eric T.; Owens, Jesse B.; Moisyadi, Stefan

    2016-01-01

    The acceptance of bioengineered plants by some nations is hampered by a number of factors, including the random insertion of a transgene into the host genome. Emerging technologies, such as site-specific nucleases, are enabling plant scientists to promote recombination or mutations at specific plant loci. Off target activity of these nucleases may limit widespread use. Insertion of transgenes by transposases engineered with a specific DNA binding domain has been accomplished in a number of or...

  12. Native cell-death genes as candidates for developing wilt resistance in transgenic banana plants.

    Science.gov (United States)

    Ghag, Siddhesh B; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2014-07-04

    In order to feed an ever-increasing world population, there is an urgent need to improve the production of staple food and fruit crops. The productivity of important food and fruit crops is constrained by numerous biotic and abiotic factors. The cultivation of banana, which is an important fruit crop, is severely threatened by Fusarium wilt disease caused by infestation by an ascomycetes fungus Fusarium oxysporum f. sp. cubense (Foc). Since there are no established edible cultivars of banana resistant to all the pathogenic races of Foc, genetic engineering is the only option for the generation of resistant cultivars. Since Foc is a hemibiotrophic fungus, investigations into the roles played by different cell-death-related genes in the progression of Foc infection on host banana plants are important. Towards this goal, three such genes namely MusaDAD1, MusaBAG1 and MusaBI1 were identified in banana. The study of their expression pattern in banana cells in response to Foc inoculation (using Foc cultures or fungal toxins like fusaric acid and beauvericin) indicated that they were indeed differentially regulated by fungal inoculation. Among the three genes studied, MusaBAG1 showed the highest up-regulation upon Foc inoculation. Further, in order to characterize these genes in the context of Foc infection in banana, we generated transgenic banana plants constitutively overexpressing the three genes that were later subjected to Foc bioassays in a contained greenhouse. Among the three groups of transgenics tested, transformed banana plants overexpressing MusaBAG1 demonstrated the best resistance towards Foc infection. Further, these plants also showed the highest relative overexpression of the transgene (MusaBAG1) among the three groups of transformed plants generated. Our study showed for the first time that native genes like MusaBAG1 can be used to develop transgenic banana plants with efficient resistance towards pathogens like Foc. Published by Oxford University Press

  13. Inverse PCR and Quantitative PCR as Alternative Methods to Southern Blotting Analysis to Assess Transgene Copy Number and Characterize the Integration Site in Transgenic Woody Plants.

    Science.gov (United States)

    Stefano, Biricolti; Patrizia, Bogani; Matteo, Cerboneschi; Massimo, Gori

    2016-06-01

    One of the major unanswered questions with respect to the commercial use of genetic transformation in woody plants is the stability of the transgene expression over several decades within the same individual. Gene expression is strongly affected by the copy number which has been integrated into the plant genome and by the local DNA features close to the integration sites. Because woody plants cannot be subjected to selfing or backcrossing to modify the transgenic allelic structure without affecting the valuable traits of the cultivar, molecular characterization of the transformation event is therefore crucial. After assessing the transgene copy number of a set of apple transgenic clones with Southern blotting, we describe two alternative methods: the first is based on inverse PCR (i-PCR) and the second on the quantitative PCR (q-PCR). The methods produced comparable results with the exception of the data regarding a high copy number clone, but while the q-PCR-based system is rapid and easily adaptable to high throughput systems, the i-PCR-based method can provide information regarding the transformation event and the characteristics of the sequences flanking the transgenic construct.

  14. Novel Pink Bollworm Resistance to the Bt Toxin Cry 1Ac: Effects on Mating, Oviposition, Larval Development and Survival

    Science.gov (United States)

    Fabrick, J.A.; Forlow Jech, L.; Henneberry, T. J.

    2009-01-01

    Bt cotton plants are genetically engineered to produce insecticidal toxins from the Bacillus thuringiensis (Bt) Berliner (Bacillales: Bacillaceae) bacterium and target key lepidopteran pests. In all previous strains of pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) selected in the laboratory for resistance to insecticidal Cry1Ac toxin using an artificial diet containing the toxin, resistance to Cry1Ac and to Bt cotton is linked to three cadherin alleles (r1, r2, and r3). In contrast, the BG(4) pink bollworm strain was selected for resistance to Bt cotton by feeding larvae for four days in each of 42 generations on bolls of ‘NuCOTN33B®’ that expressed Cry1Ac toxin. After additional selection for eleven generations on Cry1Ac-incorporated diet, the susceptibility to Cry1Ac, fecundity, egg viability, and mating of this strain (Bt4R) was compared with the unselected Cry1Ac-susceptible parent strain. Some larvae of the Bt4R strain survived on diet containing ≥ 10 µg Cry1Ac per milliliter artificial diet, but none survived on transgenic cotton bolls. In contrast to strains selected exclusively on Cry1Ac diet, some survival of progeny of reciprocal moth crosses of Bt4R resistant and Bt-susceptible strains occurred on Cry1Ac-treated diet, suggesting differences in levels of dominance. The Bt4R resistant strain does not have the r1, r2, or r3 mutant cadherin genes as do all previous strains of pink bollworm selected on Cry1Ac-treated artificial diet. The combined results suggest a mechanism of resistance to Cry1Ac that is different from previously described cadherin mutations. PMID:19613847

  15. Rapid and reliable extraction of genomic DNA from various wild-type and transgenic plants

    Directory of Open Access Journals (Sweden)

    Yang Moon-Sik

    2004-09-01

    Full Text Available Abstract Background DNA extraction methods for PCR-quality DNA from calluses and plants are not time efficient, since they require that the tissues be ground in liquid nitrogen, followed by precipitation of the DNA pellet in ethanol, washing and drying the pellet, etc. The need for a rapid and simple procedure is urgent, especially when hundreds of samples need to be analyzed. Here, we describe a simple and efficient method of isolating high-quality genomic DNA for PCR amplification and enzyme digestion from calluses, various wild-type and transgenic plants. Results We developed new rapid and reliable genomic DNA extraction method. With our developed method, plant genomic DNA extraction could be performed within 30 min. The method was as follows. Plant tissue was homogenized with salt DNA extraction buffer using hand-operated homogenizer and extracted by phenol:chloroform:isoamyl alcohol (25:24:1. After centrifugation, the supernatant was directly used for DNA template for PCR, resulting in successful amplification for RAPD from various sources of plants and specific foreign genes from transgenic plants. After precipitating the supernatant, the DNA was completely digested by restriction enzymes. Conclusion This DNA extraction procedure promises simplicity, speed, and efficiency, both in terms of time and the amount of plant sample required. In addition, this method does not require expensive facilities for plant genomic DNA extraction.

  16. Spurious polyadenylation of Norovirus Narita 104 capsid protein mRNA in transgenic plants.

    Science.gov (United States)

    Mathew, Lolita G; Maloney, Bryan; Takeda, Naokazu; Mason, Hugh S

    2011-02-01

    Noroviruses are members of the family Caliciviridae, and cause a highly communicable gastroenteritis in humans. We explored the potential to develop a plant-based vaccine against Narita 104 virus, a Genogroup II Norovirus. In stably transgenic potato, we obtained very poor expression of Narita 104 virus capsid protein (NaVCP) despite the use of a strong constitutive promoter (dual enhancer 35S) driving the native coding sequence. We identified potentially detrimental sequence motifs that could mediate aberrant mRNA processing via spurious polyadenylation signals. Northern blots and RT-PCR analysis of total RNA revealed truncated transcripts that suggested premature polyadenylation. Site-directed mutagenesis to remove one potential polyadenylation near-upstream element resulted in an increased expression of NaVCP when transiently expressed in leaves of Nicotiana benthamiana. Further, cloning of the truncated cDNAs from transgenic NaVCP potato plants and transiently transfected N. benthamiana allowed us to identify at least ten different truncated transcripts resulting from premature polyadenylation of full length NaVCP transcripts. Comparative studies using real time PCR analysis from cDNA samples revealed lower accumulation of full length transcripts of NaVCP as compared to those from a gene encoding Norwalk Virus capsid protein (a related Genogroup I Norovirus) in transiently transfected plants. These findings provide evidence for impaired expression of NaVCP in transgenic plants mediated by spurious polyadenylation signals, and demonstrate the need to scrupulously search for potential polyadenylation signals in order to improve transgene expression in plants.

  17. Soybean GmMYB73 promotes lipid accumulation in transgenic plants

    Science.gov (United States)

    2014-01-01

    Background Soybean is one of the most important oil crops. The regulatory genes involved in oil accumulation are largely unclear. We initiated studies to identify genes that regulate this process. Results One MYB-type gene GmMYB73 was found to display differential expression in soybean seeds of different developing stages by microarray analysis and was further investigated for its functions in lipid accumulation. GmMYB73 is a small protein with single MYB repeat and has similarity to CPC-like MYB proteins from Arabidopsis. GmMYB73 interacted with GL3 and EGL3, and then suppressed GL2, a negative regulator of oil accumulation. GmMYB73 overexpression enhanced lipid contents in both seeds and leaves of transgenic Arabidopsis plants. Seed length and thousand-seed weight were also promoted. GmMYB73 introduction into the Arabidopsis try cpc double mutant rescued the total lipids, seed size and thousand-seed weight. GmMYB73 also elevated lipid levels in seeds and leaves of transgenic Lotus, and in transgenic hairy roots of soybean plants. GmMYB73 promoted PLDα1 expression, whose promoter can be bound and inhibited by GL2. PLDα1 mutation reduced triacylglycerol levels mildly in seeds but significantly in leaves of Arabidopsis plants. Conclusions GmMYB73 may reduce GL2, and then release GL2-inhibited PLDα1 expression for lipid accumulation. Manipulation of GmMYB73 may potentially improve oil production in legume crop plants. PMID:24655684

  18. Application of Cry1Ab/Ac Bt strip for screening of resistance for ...

    African Journals Online (AJOL)

    In this study, the efficacy of using Cry1Ab/Ac Bt strip for detecting Maruca resistant transgene in transgenic cowpea was systematically investigated for the first time through field derived progenies. The results show that the Cry1Ab/Ac Bt strip was effective for detecting the presence of the resistant gene in cowpea genome.

  19. Overexpression of the Wheat Expansin Gene TaEXPA2 Improved Seed Production and Drought Tolerance in Transgenic Tobacco Plants.

    Directory of Open Access Journals (Sweden)

    Yanhui Chen

    Full Text Available Expansins are cell wall proteins that are grouped into two main families, α-expansins and β-expansins, and they are implicated in the control of cell extension via the disruption of hydrogen bonds between cellulose and matrix glucans. TaEXPA2 is an α-expansin gene identified in wheat. Based on putative cis-regulatory elements in the TaEXPA2 promoter sequence and the expression pattern induced when polyethylene glycol (PEG is used to mimic water stress, we hypothesized that TaEXPA2 is involved in plant drought tolerance and plant development. Through transient expression of 35S::TaEXPA2-GFP in onion epidermal cells, TaEXPA2 was localized to the cell wall. Constitutive expression of TaEXPA2 in tobacco improved seed production by increasing capsule number, not seed size, without having any effect on plant growth patterns. The transgenic tobacco exhibited a significantly greater tolerance to water-deficiency stress than did wild-type (WT plants. We found that under drought stress, the transgenic plants maintained a better water status. The accumulated content of osmotic adjustment substances, such as proline, in TaEXPA2 transgenic plants was greater than that in WT plants. Transgenic plants also displayed greater antioxidative competence as indicated by their lower malondialdehyde (MDA content, relative electrical conductivity, and reactive oxygen species (ROS accumulation than did WT plants. This result suggests that the transgenic plants suffer less damage from ROS under drought conditions. The activities of some antioxidant enzymes as well as expression levels of several genes encoding key antioxidant enzymes were higher in the transgenic plants than in the WT plants under drought stress. Collectively, our results suggest that ectopic expression of the wheat expansin gene TaEXPA2 improves seed production and drought tolerance in transgenic tobacco plants.

  20. Overexpression of the Wheat Expansin Gene TaEXPA2 Improved Seed Production and Drought Tolerance in Transgenic Tobacco Plants

    Science.gov (United States)

    Chen, Yanhui; Han, Yangyang; Zhang, Meng; Zhou, Shan; Kong, Xiangzhu; Wang, Wei

    2016-01-01

    Expansins are cell wall proteins that are grouped into two main families, α-expansins and β-expansins, and they are implicated in the control of cell extension via the disruption of hydrogen bonds between cellulose and matrix glucans. TaEXPA2 is an α-expansin gene identified in wheat. Based on putative cis-regulatory elements in the TaEXPA2 promoter sequence and the expression pattern induced when polyethylene glycol (PEG) is used to mimic water stress, we hypothesized that TaEXPA2 is involved in plant drought tolerance and plant development. Through transient expression of 35S::TaEXPA2-GFP in onion epidermal cells, TaEXPA2 was localized to the cell wall. Constitutive expression of TaEXPA2 in tobacco improved seed production by increasing capsule number, not seed size, without having any effect on plant growth patterns. The transgenic tobacco exhibited a significantly greater tolerance to water-deficiency stress than did wild-type (WT) plants. We found that under drought stress, the transgenic plants maintained a better water status. The accumulated content of osmotic adjustment substances, such as proline, in TaEXPA2 transgenic plants was greater than that in WT plants. Transgenic plants also displayed greater antioxidative competence as indicated by their lower malondialdehyde (MDA) content, relative electrical conductivity, and reactive oxygen species (ROS) accumulation than did WT plants. This result suggests that the transgenic plants suffer less damage from ROS under drought conditions. The activities of some antioxidant enzymes as well as expression levels of several genes encoding key antioxidant enzymes were higher in the transgenic plants than in the WT plants under drought stress. Collectively, our results suggest that ectopic expression of the wheat expansin gene TaEXPA2 improves seed production and drought tolerance in transgenic tobacco plants. PMID:27073898

  1. Genetic engineering of novel flower colors in floricultural plants: recent advances via transgenic approaches.

    Science.gov (United States)

    Nishihara, Masahiro; Nakatsuka, Takashi

    2010-01-01

    Since the first successful genetic engineering of flower color in petunia, several new techniques have been developed and applied to modify flower color not only in model plants but also in floricultural plants. A typical example is the commercial violet-flowered carnation "Moondust series" developed by Suntry Ltd. and Florigene Ltd. More recently, blue-flowered roses have been successfully produced and are expected to be commercially available in the near future. In recent years, successful modification of flower color by sophisticated regulation of flower-pigment metabolic pathways has become possible. In this chapter, we review recent advances in flower color modification by genetic engineering, especially focusing on the methodology. We have included our own recent results on successful production of flower-color-modified transgenic plants in a model plant, tobacco and an ornamental plant, gentian. Based on these results, genetic engineering of flower color for improvement of floricultural plants is discussed.

  2. Regeneration of transgenic cassava plants (Manihot esculenta Crantz) from microbombarded embryogenic suspension cultures.

    Science.gov (United States)

    Schöpke, C; Taylor, N; Cárcamo, R; Konan, N K; Marmey, P; Henshaw, G G; Beachy, R N; Fauquet, C

    1996-06-01

    A protocol was established for the introduction of DNA into embryogenic suspension-derived tissues of cassava via microparticle bombardment, for the selection of genetically transformed cells, and for the regeneration of fully transgenic plants from these cells. The plasmid DNA used for bombardment contained a gene encoding neomycin phosphotransferase (nptII) and a gene encoding beta-glucuronidase (uidA). Selection of bombarded tissue with paromomycin resulted in the establishment of putative transgenic embryogenic calli. In most of these calli, beta-glucuronidase was detected histochemically. Molecular analysis of paromomycin-resistant embryogenic calli and of plants regenerated from these calli, confirmed the stable integration of bombarded DNA into the cassava genome.

  3. Regulating transgenic crops sensibly: lessons from plant breeding, biotechnology and genomics.

    Science.gov (United States)

    Bradford, Kent J; Van Deynze, Allen; Gutterson, Neal; Parrott, Wayne; Strauss, Steven H

    2005-04-01

    The costs of meeting regulatory requirements and market restrictions guided by regulatory criteria are substantial impediments to the commercialization of transgenic crops. Although a cautious approach may have been prudent initially, we argue that some regulatory requirements can now be modified to reduce costs and uncertainty without compromising safety. Long-accepted plant breeding methods for incorporating new diversity into crop varieties, experience from two decades of research on and commercialization of transgenic crops, and expanding knowledge of plant genome structure and dynamics all indicate that if a gene or trait is safe, the genetic engineering process itself presents little potential for unexpected consequences that would not be identified or eliminated in the variety development process before commercialization. We propose that as in conventional breeding, regulatory emphasis should be on phenotypic rather than genomic characteristics once a gene or trait has been shown to be safe.

  4. COMPARATIVE MOLECULAR GENETIC ANALYSIS BETWEEN UKRAINIAN AND EU REGISTERED GLYPHOSATE-TOLERANT RAPESEED TRANSGENIC PLANTS

    Directory of Open Access Journals (Sweden)

    A. M. Taranenko

    2015-04-01

    Full Text Available The purpose of research was to analyze 10 developed at the Institute of Cell Biology and Genetic Engineering lines of rapeseed to confirm the presence and functionality of the transferred transgene CP4 epsps, as well as the differences among those lines from registered transformation events GT73 and GT200 (Monsanto. During the study extraction of total rapeseed DNA, PCR analysis, electrophoretic separation and visualization of amplicons in agarose gel were conducted, as well as testing of green plants for resistance to glyphosate in greenhouse. The structural difference among 7 transgenic lines from registered transformation events GT73 and GT200 was revealed. Plants showing the presence of synthetic CP4 epsps sequence were resistant to the herbicide in a closed soil. The uniqueness of the obtained transformation events was confirmed, as well as the prospect of using them in breeding.

  5. Very bright orange fluorescent plants: endoplasmic reticulum targeting of orange fluorescent proteins as visual reporters in transgenic plants

    Directory of Open Access Journals (Sweden)

    Mann David GJ

    2012-05-01

    Full Text Available Abstract Background The expression of fluorescent protein (FP genes as real-time visual markers, both transiently and stably, has revolutionized plant biotechnology. A palette of colors of FPs is now available for use, but the diversity has generally been underutilized in plant biotechnology. Because of the green and far-red autofluorescent properties of many plant tissues and the FPs themselves, red and orange FPs (RFPs, and OFPs, respectfully appear to be the colors with maximum utility in plant biotechnology. Within the color palette OFPs have emerged as the brightest FP markers in the visible spectra. This study compares several native, near-native and modified OFPs for their “brightness” and fluorescence, therefore, their usability as marker genes in transgenic plant tissues. Results The OFPs DsRed2, tdTomato, mOrange and pporRFP were all expressed under the control of the CaMV 35S promoter in agroinfiltration-mediated transient assays in Nicotiana benthamiana. Each of these, as well as endoplasmic reticulum (ER-targeted versions, were stably expressed in transgenic Nicotiana tabacum and Arabidopsis thaliana. Congruent results were observed between transient and stable assays. Our results demonstrated that there are several adequate OFP genes available for plant transformation, including the new pporRFP, an unaltered tetramer from the hard coral Porites porites. When the tandem dimer tdTomato and the monomeric mOrange were targeted to the ER, dramatic, ca. 3-fold, increase in plant fluorescence was observed. Conclusions From our empirical data, and a search of the literature, it appears that tdTomato-ER and mOrange-ER are the two highest fluorescing FPs available as reporters for transgenic plants. The pporRFP is a brightly fluorescing tetramer, but all tetramer FPs are far less bright than the ER-targeted monomers we report here.

  6. Overexpression of persimmon DkXTH1 enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.

    Science.gov (United States)

    Han, Ye; Han, Shoukun; Ban, Qiuyan; He, Yiheng; Jin, Mijing; Rao, Jingping

    2017-04-01

    DkXTH1 promoted cell elongation and more strength to maintain structural integrity by involving in cell wall assembly, thus enhanced tolerance to abiotic stress with broader phenotype in transgenic plants. Xyloglucan endotransglucosylase/hydrolase (XTH) is thought to play a key role in cell wall modifications by cleaving and re-joining xyloglucan, and participates in the diverse physiological processes. DkXTH1 was found to peak in immature expanding persimmon fruit, and its higher expression level exhibited along with firmer fruit during storage. In the present study, transgenic Arabidopsis and tomato plants were generated with DkXTH1 constitutively expressed. Overexpression of DkXTH1 enhanced tolerance to salt, ABA and drought stresses in transgenic Arabidopsis plants with respect to root and leaf growth, and survival. Transgenic tomatoes collected at the mature green stage, presented delayed fruit softening coupled with postponed color change, a later and lower ethylene peak, and higher firmness in comparison with the wild-type tomatoes during storage. Furthermore, broader leaves and tomato fruit with larger diameter were gained in transgenic Arabidopsis and tomato, respectively. Most importantly, transgenic plants exhibited more large and irregular cells with higher density of cell wall and intercellular spaces, resulting from the overactivity of XET enzymes involving in cell wall assembly. We suggest that DkXTH1 expression resulted in cells with more strength and thickness to maintain structural integrity, and thus enhanced tolerance to abiotic stress and delayed fruit softening in transgenic plants.

  7. Soybean GmbZIP123 gene enhances lipid content in the seeds of transgenic Arabidopsis plants.

    Science.gov (United States)

    Song, Qing-Xin; Li, Qing-Tian; Liu, Yun-Feng; Zhang, Feng-Xia; Ma, Biao; Zhang, Wan-Ke; Man, Wei-Qun; Du, Wei-Guang; Wang, Guo-Dong; Chen, Shou-Yi; Zhang, Jin-Song

    2013-11-01

    Soybean is one of most important oil crops and a significant increase in lipid content in soybean seeds would facilitate vegetable oil production in the world. Although the pathways for lipid biosynthesis in higher plants have been uncovered, our understanding of regulatory mechanism controlling lipid accumulation is still limited. In this study, we identified 87 transcription factor genes with a higher abundance at the stage of lipid accumulation in soybean seeds. One of these genes, GmbZIP123, was selected to further study its function in regulation of lipid accumulation. Overexpression of GmbZIP123 enhanced lipid content in the seeds of transgenic Arabidopsis thaliana plants. The GmbZIP123 transgene promoted expression of two sucrose transporter genes (SUC1 and SUC5) and three cell-wall invertase genes (cwINV1, cwINV3, and cwINV6) by binding directly to the promoters of these genes. Consistently, the cell-wall invertase activity and sugar translocation were all enhanced in siliques of GmbZIP123 transgenic plants. Higher levels of glucose, fructose, and sucrose were also found in seeds of GmbZIP123 transgenic plants. These results suggest that GmbZIP123 may participate in regulation of lipid accumulation in soybean seeds by controlling sugar transport into seeds from photoautotrophic tissues. This study provides novel insights into the regulatory mechanism for lipid accumulation in seeds and may facilitate improvements in oil production in soybean and other oil crops through genetic manipulation of the GmbZIP123 gene.

  8. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene.

    Directory of Open Access Journals (Sweden)

    Nidhi Thakur

    Full Text Available BACKGROUND: Expression of double strand RNA (dsRNA designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi, thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci upon oral feeding. The v-ATPase subunit A (v-ATPaseA coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation. METHODOLOGY/PRINCIPAL FINDINGS: Transgenic tobacco lines were developed for the expression of long dsRNA precursor to make siRNA and knock down the v-ATPaseA mRNA in whitefly. Molecular analysis and insecticidal properties of the transgenic plants established the formation of siRNA targeting the whitefly v-ATPaseA, in the leaves. The transcript level of v-ATPaseA in whiteflies was reduced up to 62% after feeding on the transgenic plants. Heavy infestation of whiteflies on the control plants caused significant loss of sugar content which led to the drooping of leaves. The transgenic plants did not show drooping effect. CONCLUSIONS/SIGNIFICANCE: Host plant derived pest resistance was achieved against whiteflies by genetic transformation of tobacco which generated siRNA against the whitefly v-ATPaseA gene. Transgenic tobacco lines expressing dsRNA of v-ATPaseA, delivered sufficient siRNA to whiteflies feeding on them, mounting a significant silencing response, leading to their mortality. The transcript level of the target gene was reduced in whiteflies feeding on transgenic plants. The strategy can be taken up for genetic engineering of plants to control whiteflies in field crops.

  9. Agrobacterium-mediated transformation of safflower and the efficient recovery of transgenic plants via grafting

    Directory of Open Access Journals (Sweden)

    Singh Surinder P

    2011-05-01

    Full Text Available Abstract Background Safflower (Carthamus tinctorius L. is a difficult crop to genetically transform being susceptible to hyperhydration and poor in vitro root formation. In addition to traditional uses safflower has recently emerged as a broadacre platform for the production of transgenic products including modified oils and pharmaceutically active proteins. Despite commercial activities based on the genetic modification of safflower, there is no method available in the public domain describing the transformation of safflower that generates transformed T1 progeny. Results An efficient and reproducible protocol has been developed with a transformation efficiency of 4.8% and 3.1% for S-317 (high oleic acid content and WT (high linoleic acid content genotypes respectively. An improved safflower transformation T-DNA vector was developed, including a secreted GFP to allow non-destructive assessment of transgenic shoots. Hyperhydration and necrosis of Agrobacterium-infected cotyledons was effectively controlled by using iota-carrageenan, L-cysteine and ascorbic acid. To overcome poor in vitro root formation for the first time a grafting method was developed for safflower in which ~50% of transgenic shoots develop into mature plants bearing viable transgenic T1 seed. The integration and expression of secreted GFP and hygromycin genes were confirmed by PCR, Southern and Western blot analysis. Southern blot analysis in nine independent lines indicated that 1-7 transgenes were inserted per line and T1 progeny displayed Mendelian inheritance. Conclusions This protocol demonstrates significant improvements in both the efficiency and ease of use over existing safflower transformation protocols. This is the first complete method of genetic transformation of safflower that generates stably-transformed plants and progeny, allowing this crop to benefit from modern molecular applications.

  10. Synthetic TAL effectors for targeted enhancement of transgene expression in plants.

    Science.gov (United States)

    Liu, Wusheng; Rudis, Mary R; Peng, Yanhui; Mazarei, Mitra; Millwood, Reginald J; Yang, Jian-Ping; Xu, Wenzhi; Chesnut, Jonathan D; Stewart, Charles Neal

    2014-05-01

    Transcription activator-like effectors (TALEs), secreted by the pathogenic bacteria Xanthomonas, specifically activate expression of targeted genes in plants. Here, we designed synthetic TALEs that bind to the flanking regions of the TATA-box motif on the CaMV 35S promoter for the purpose of understanding the engineerable 'hot-spots' for increasing transgene expression. We demonstrated that transient expression of de novo-engineered TALEs using agroinfiltration could significantly increase reporter gene expression in stable transgenic tobacco expressing the orange fluorescent protein reporter gene pporRFP under the control of synthetic inducible, minimal or full-length 35S promoters. Moreover, the additive effects of a combination of two different synthetic TALEs could significantly enhance the activation effects of TALEs on reporter gene expression more than when each TALE was used individually. We also studied the effects of the C-terminal domain and the activation domain of synthetic TALEs, as well as the best 'hot-spots' on the 35S promoter on targeted transgene activation. Furthermore, TALE activation of the Arabidopsis MYB transcription factor AtPAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT 1) in stable transgenic tobacco gave rise to a dark purple colour on infiltrated leaves when driven by four copies of cis-regulatory elements of pathogenesis-related gene (PR1) with enhancer motifs B and A1 from the 35S promoter. These results provide novel insights into the potential applications of synthetic TALEs for targeted gene activation of transgenes in plants. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  11. Salt tolerant SUV3 overexpressing transgenic rice plants conserve physicochemical properties and microbial communities of rhizosphere.

    Science.gov (United States)

    Sahoo, Ranjan K; Ansari, Mohammad W; Tuteja, Renu; Tuteja, Narendra

    2015-01-01

    Key concerns in the ecological evaluation of GM crops are undesirably spread, gene flow, other environmental impacts, and consequences on soil microorganism's biodiversity. Numerous reports have highlighted the effects of transgenic plants on the physiology of non-targeted rhizospheric microbes and the food chain via causing adverse effects. Therefore, there is an urgent need to develop transgenics with insignificant toxic on environmental health. In the present study, SUV3 overexpressing salt tolerant transgenic rice evaluated in New Delhi and Cuttack soil conditions for their effects on physicochemical and biological properties of rhizosphere. Its cultivation does not affect soil properties viz., pH, Eh, organic C, P, K, N, Ca, Mg, S, Na and Fe(2+). Additionally, SUV3 rice plants do not cause any change in the phenotype, species characteristics and antibiotic sensitivity of rhizospheric bacteria. The population and/or number of soil organisms such as bacteria, fungi and nematodes were unchanged in the soil. Also, the activity of bacterial enzymes viz., dehydrogenase, invertase, phenol oxidases, acid phosphatases, ureases and proteases was not significantly affected. Further, plant growth promotion (PGP) functions of bacteria such as siderophore, HCN, salicylic acid, IAA, GA, zeatin, ABA, NH3, phosphorus metabolism, ACC deaminase and iron tolerance were, considerably, not influenced. The present findings suggest ecologically pertinent of salt tolerant SUV3 rice to sustain the health and usual functions of the rhizospheric organisms. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Striga parasitizes transgenic hairy roots of Zea mays and provides a tool for studying plant-plant interactions

    Directory of Open Access Journals (Sweden)

    Runo Steven

    2012-06-01

    Full Text Available Abstract Background Striga species are noxious root hemi-parasitic weeds that debilitate cereal production in sub-Saharan Africa (SSA. Control options for Striga are limited and developing Striga resistant crop germplasm is regarded as the best and most sustainable control measure. Efforts to improve germplasm for Striga resistance by a non-Genetic Modification (GM approach, for example by exploiting natural resistance, or by a GM approach are constrained by limited information on the biological processes underpinning host-parasite associations. Additionaly, a GM approach is stymied by lack of availability of candidate resistance genes for introduction into hosts and robust transformation methods to validate gene functions. Indeed, a majority of Striga hosts, the world’s most cultivated cereals, are recalcitrant to genetic transformation. In maize, the existing protocols for transformation and regeneration are tedious, lengthy, and highly genotype-specific with low efficiency of transformation. Results We used Agrobacterium rhizogenes strain K599 carrying a reporter gene construct, Green Fluorescent Protein (GFP, to generate transgenic composite maize plants that were challenged with the parasitic plant Striga hermonthica. Eighty five percent of maize plants produced transgenic hairy roots expressing GFP. Consistent with most hairy roots produced in other species, transformed maize roots exhibited a hairy root phenotype, the hallmark of A. rhizogenes mediated transformation. Transgenic hairy roots resulting from A. rhizogenes transformation were readily infected by S. hermonthica. There were no significant differences in the number and size of S. hermonthica individuals recovered from either transgenic or wild type roots. Conclusions This rapid, high throughput, transformation technique will advance our understanding of gene function in parasitic plant-host interactions.

  13. Striga parasitizes transgenic hairy roots of Zea mays and provides a tool for studying plant-plant interactions.

    Science.gov (United States)

    Runo, Steven; Macharia, Sarah; Alakonya, Amos; Machuka, Jesse; Sinha, Neelima; Scholes, Julie

    2012-06-21

    Striga species are noxious root hemi-parasitic weeds that debilitate cereal production in sub-Saharan Africa (SSA). Control options for Striga are limited and developing Striga resistant crop germplasm is regarded as the best and most sustainable control measure. Efforts to improve germplasm for Striga resistance by a non-Genetic Modification (GM) approach, for example by exploiting natural resistance, or by a GM approach are constrained by limited information on the biological processes underpinning host-parasite associations. Additionaly, a GM approach is stymied by lack of availability of candidate resistance genes for introduction into hosts and robust transformation methods to validate gene functions. Indeed, a majority of Striga hosts, the world's most cultivated cereals, are recalcitrant to genetic transformation. In maize, the existing protocols for transformation and regeneration are tedious, lengthy, and highly genotype-specific with low efficiency of transformation. We used Agrobacterium rhizogenes strain K599 carrying a reporter gene construct, Green Fluorescent Protein (GFP), to generate transgenic composite maize plants that were challenged with the parasitic plant Striga hermonthica. Eighty five percent of maize plants produced transgenic hairy roots expressing GFP. Consistent with most hairy roots produced in other species, transformed maize roots exhibited a hairy root phenotype, the hallmark of A. rhizogenes mediated transformation. Transgenic hairy roots resulting from A. rhizogenes transformation were readily infected by S. hermonthica. There were no significant differences in the number and size of S. hermonthica individuals recovered from either transgenic or wild type roots. This rapid, high throughput, transformation technique will advance our understanding of gene function in parasitic plant-host interactions.

  14. Expression of a functional human adenosine deaminase in transgenic tobacco plants.

    Science.gov (United States)

    Singhabahu, Sanjeewa; George, John; Bringloe, David

    2013-06-01

    An inherited disorder, adenosine deaminase deficiency is a form of severe combined immunodeficiency, which is ultimately caused by an absence of adenosine deaminase (ADA), a key enzyme of the purine salvage pathway. The absence of ADA-activity in sufferers eventually results in a dysfunctional immune system due to the build-up of toxic metabolites. To date, this has been treated with mixed success, using PEG-ADA, made from purified bovine ADA coupled to polyethylene glycol. It is likely, however, that an enzyme replacement therapy protocol based on recombinant human ADA would be a more effective treatment for this disease. Therefore, as a preliminary step to produce biologically active human ADA in transgenic tobacco plants a human ADA cDNA has been inserted into a plant expression vector under the control of the CaMV 35S promoter and both human and TMV 5' UTR control regions. Plant vector expression constructs have been used to transform tobacco plants via Agrobacterium-mediated transformation. Genomic DNA, RNA and protein blot analyses have demonstrated the integration of the cDNA construct into the plant nuclear genome and the expression of recombinant ADA mRNA and protein in transgenic tobacco leaves. Western blot analysis has also revealed that human and recombinant ADA have a similar size of approximately 41 kDa. ADA-specific activities of between 0.001 and 0.003 units per mg total soluble protein were measured in crude extracts isolated from transformed tobacco plant leaves.

  15. Complex Outcomes from Insect and Weed Control with Transgenic Plants: Ecological Surprises?

    Directory of Open Access Journals (Sweden)

    Thomas Bøhn

    2017-09-01

    Full Text Available Agriculture is fundamental for human survival through food production and is performed in ecosystems that, while simplified, still operate along ecological principles and retain complexity. Agricultural plants are thus part of ecological systems, and interact in complex ways with the surrounding terrestrial, soil, and aquatic habitats. We discuss three case studies that demonstrate how agricultural solutions to pest and weed control, if they overlook important ecological and evolutionary factors, cause “surprises”: (i the fast emergence of resistance against the crop-inserted Bt-toxin in South Africa, (ii the ecological changes generated by Bt-cotton landscapes in China, and (iii the decline of the monarch butterfly, Danaus plexippus, in North America. The recognition that we work with complex systems is in itself important, as it should limit the belief in reductionist solutions. Agricultural practices lacking eco-evolutionary understanding result in “surprises” like resistance evolution both in weeds and pest insects, risking the reappearance of the “pesticide treadmill”—with increased use of toxic pesticides as the follow-up. We recommend prioritization of research that counteracts the tendencies of reductionist approaches. These may be beneficial on a short term, but with trade-off costs on a medium- to long-term. Such costs include loss of biodiversity, ecosystem services, long-term soil productivity, pollution, and reduced food quality.

  16. In vitro culture may be the major contributing factor for transgenic versus nontransgenic proteomic plant differences.

    Science.gov (United States)

    Fonseca, Cátia; Planchon, Sébastien; Serra, Tânia; Chander, Subhash; Saibo, Nelson J M; Renaut, Jenny; Oliveira, M Margarida; Batista, Rita

    2015-01-01

    Identification of differences between genetically modified plants and their original counterparts plays a central role in risk assessment strategy. Our main goal was to better understand the relevance of transgene presence, genetic, and epigenetic changes induced by transgene insertion, and in vitro culture in putative unintended differences between a transgenic and its comparator. Thus, we have used multiplex fluorescence 2DE coupled with MS to characterize the proteome of three different rice lines (Oryza sativa L. ssp. japonica cv. Nipponbare): a control conventional line (C), an Agrobacterium-transformed transgenic line (Ta) and a negative segregant (NSb). We observed that Ta and NSb appeared identical (with only one spot differentially abundant--fold difference ≥ 1.5), contrasting with the control (49 spots with fold difference ≥ 1.5, in both Ta and NSb vs. control). Given that in vitro culture was the only event in common between Ta and NSb, we hypothesize that in vitro culture stress was the most relevant condition contributing for the observed proteomic differences. MS protein identification support our hypothesis, indicating that Ta and NSb lines adjusted their metabolic pathways and altered the abundance of several stress related proteins in order to cope with in vitro culture. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Increased mortality is predicted of Inachis io larvae caused by Bt-maize pollen in European farmland

    DEFF Research Database (Denmark)

    Holst, Niels; Lang, Andreas; Lövei, Gabor L

    2013-01-01

    A potential environmental risk of the field cultivation of insect-resistant (Bt-toxin expressing) transgenic maize (Zea mays) is the consumption of Bt-containing pollen by herbivorous larvae of butterflies (Lepidoptera). Maize is wind-pollinated, and at flowering time large amounts of pollen can...... be deposited on various plants growing in the landscape, leading to inadvertent ingestion of toxic pollen with plant biomass consumed by these butterfly larvae. To examine the possible effect of this coincidence, we focused our study on the protected butterfly Inachis io and two regions of Europe. Using...... climatic records, maize and butterfly phenology data, we built a simulation model of the butterfly's annual life cycle, overlaid with the phenology of maize pollen deposition on the leaves of the food plant Urtica dioica, and linked these with the dose–response curve of I. io larvae to Bt-maize pollen...

  18. Cis-mediated down-regulation of a trypsin gene associated with Bt resistance in cotton bollworm.

    Science.gov (United States)

    Liu, Chenxi; Xiao, Yutao; Li, Xianchun; Oppert, Brenda; Tabashnik, Bruce E; Wu, Kongming

    2014-11-27

    Transgenic plants producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are useful for pest control, but their efficacy is reduced when pests evolve resistance. Here we examined the mechanism of resistance to Bt toxin Cry1Ac in the laboratory-selected LF5 strain of the cotton bollworm, Helicoverpa armigera. This strain had 110-fold resistance to Cry1Ac protoxin and 39-fold resistance to Cry1Ac activated toxin. Evaluation of five trypsin genes revealed 99% reduced transcription of one trypsin gene (HaTryR) was associated with resistance. Silencing of this gene with RNA interference in susceptible larvae increased their survival on diets containing Cry1Ac. Bioassays of progeny from crosses revealed that resistance to Cry1Ac was genetically linked with HaTryR. We identified mutations in the promoter region of HaTryR in the resistant strain. In transfected insect cell lines, transcription was lower when driven by the resistant promoter compared with the susceptible promoter, implicating cis-mediated down-regulation of HaTryR transcription as a mechanism of resistance. The results suggest that H. armigera can adapt to Bt toxin Cry1Ac by decreased expression of trypsin. Because trypsin activation of protoxin is a critical step in toxicity, transgenic plants with activated toxins rather than protoxins might increase the durability of Bt crops.

  19. Expression of recombinant antibody (single chain antibody fragment) in transgenic plant Nicotiana tabacum cv. Xanthi.

    Science.gov (United States)

    Dobhal, S; Chaudhary, V K; Singh, A; Pandey, D; Kumar, A; Agrawal, S

    2013-12-01

    Plants offer an alternative inexpensive and convenient technology for large scale production of recombinant proteins especially recombinant antibodies (plantibodies). In this paper, we describe the expression of a model single chain antibody fragment (B6scFv) in transgenic tobacco. Four different gene constructs of B6scFv with different target signals for expression in different compartments of a tobacco plant cell with and without endoplasmic reticulum (ER) retention signal were used. Agrobacterium mediated plant transformation of B6scFv gene was performed with tobacco leaf explants and the gene in regenerated plants was detected using histochemical GUS assay and PCR. The expression of B6scFv gene was detected by western blotting and the recombinant protein was purified from putative transgenic tobacco plants using metal affinity chromatography. The expression level of recombinant protein was determined by indirect enzyme-linked immunosorbent assay. The highest accumulation of protein was found up to 3.28 % of the total soluble protein (TSP) in plants expressing B6scFv 1003 targeted to the ER, and subsequently expression of 2.9 % of TSP in plants expressing B6scFv 1004 (with target to apoplast with ER retention signal). In contrast, lower expression of 0.78 and 0.58 % of TSP was found in plants expressing antibody fragment in cytosol and apoplast, without ER retention signal. The described method/system could be used in the future for diverse applications including expression of other recombinant molecules in plants for immunomodulation, obtaining pathogen resistance against plant pathogens, altering metabolic pathways and also for the expression of different antibodies of therapeutic and diagnostic uses.

  20. Silencing the HaAK gene by transgenic plant-mediated RNAi impairs larval growth of Helicoverpa armigera.

    Science.gov (United States)

    Liu, Feng; Wang, Xiao-Dong; Zhao, Yi-Ying; Li, Yan-Jun; Liu, Yong-Chang; Sun, Jie

    2015-01-01

    Insect pests have caused noticeable economic losses in agriculture, and the heavy use of insecticide to control pests not only brings the threats of insecticide resistance but also causes the great pollution to foods and the environment. Transgenic plants producing double-stranded RNA (dsRNA) directed against insect genes have been is currently developed for protection against insect pests. In this study, we used this technology to silence the arginine kinase (AK) gene of Helicoverpa armigera (HaAK), encoding a phosphotransferase that plays a critical role in cellular energy metabolism in invertebrate. Transgenic Arabidopsis plants producing HaAK dsRNA were generated by Agrobacterium-mediated transformation. The maximal mortality rate of 55% was reached when H. armigera first-instar larvae were fed with transgenic plant leaves for 3 days, which was dramatically higher than the 18% mortality recorded in the control group. Moreover, the ingestion of transgenic plants significantly retarded larval growth, and the transcript levels of HaAK were also knocked down by up to 52%. The feeding bioassays further indicated that the inhibition efficiency was correlated with the integrity and concentration of the produced HaAK dsRNA in transgenic plants. These results strongly show that the resistance to H. armigera was improved in transgenic Arabidopsis plants, suggesting that the RNAi targeting of AK has the potential for the control of insect pests.

  1. The food and environmental safety of Bt crops

    Science.gov (United States)

    Koch, Michael S.; Ward, Jason M.; Levine, Steven L.; Baum, James A.; Vicini, John L.; Hammond, Bruce G.

    2015-01-01

    Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms. PMID:25972882

  2. The Food and Environmental Safety of Bt Crops

    Directory of Open Access Journals (Sweden)

    Michael Stephen Koch

    2015-04-01

    Full Text Available Bt (Bacillus thuringiensis microbial pesticides have a 50-year history of safe use in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s. Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms.

  3. Constitutive expression of CaPLA1 conferred enhanced growth and grain yield in transgenic rice plants.

    Science.gov (United States)

    Park, Ki Youl; Kim, Eun Yu; Seo, Young Sam; Kim, Woo Taek

    2016-03-01

    Phospholipids are not only important components of cell membranes, but participate in diverse processes in higher plants. In this study, we generated Capsicum annuum phospholipiase A1 (CaPLA1) overexpressing transgenic rice (Oryza sativa L.) plants under the control of the maize ubiquitin promoter. The T4 CaPLA1-overexpressing rice plants (Ubi:CaPLA1) had a higher root:shoot mass ratio than the wild-type plants in the vegetative stage. Leaf epidermal cells from transgenic plants had more cells than wild-type plants. Genes that code for cyclin and lipid metabolic enzymes were up-regulated in the transgenic lines. When grown under typical paddy field conditions, the transgenic plants produced more tillers, longer panicles and more branches per panicle than the wild-type plants, all of which resulted in greater grain yield. Microarray analysis suggests that gene expressions that are related with cell proliferation, lipid metabolism, and redox state were widely altered in CaPLA1-overexpressing transgenic rice plants. Ubi:CaPLA1 plants had a reduced membrane peroxidation state, as determined by malondialdehyde and conjugated diene levels and higher peroxidase activity than wild-type rice plants. Furthermore, three isoprenoid synthetic genes encoding terpenoid synthase, hydroxysteroid dehydrogenase and 3-hydroxy-3-methyl-glutaryl-CoA reductase were up-regulated in CaPLA1-overexpressing plants. We suggest that constitutive expression of CaPLA1 conferred increased grain yield with enhanced growth in transgenic rice plants by alteration of gene activities related with cell proliferation, lipid metabolism, membrane peroxidation state and isoprenoid biosynthesis.

  4. Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

    Science.gov (United States)

    Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

    2016-03-01

    RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes.

  5. Effect of Bt-176 maize pollen on first instar larvae of the Peacock butterfly (Inachis io) (Lepidoptera; Nymphalidae).

    Science.gov (United States)

    Felke, Martin; Langenbruch, Gustav-Adolf; Feiertag, Simon; Kassa, Adane

    2010-01-01

    More than 10 years after registration of the first Bt maize cultivar in Europe, there still exists a remarkable lack of data on effects on Lepidoptera which would be necessary for a complete and comprehensive environmental risk assessment. So far only very few European butterfly species have been tested in this aspect. In our study the effect of transgenic Bacillus thuringiensis (Bt) maize pollen (event Bt-176) on the development and survival of neonate larvae of the Peacock butterfly, Inachis io (L.) was for the first time shown. The results of our study suggest that the Peacock butterfly may serve as a model organism for assessing potential side effects of new developed transgenic Bt crops on non-target butterflies in a GMO environmental risk assessment. The study was done under laboratory conditions by exposing larvae of the Peacock butterfly to various pollen doses of transgenic maize event Bt-176 (cv. PACTOL CB) or the conventional isogenic maize (cv. PACTOL) using a no-choice test. Larvae feeding for 48 h on nettle plants (Urtica dioica) that were contaminated with higher pollen concentrations from Bt-176 maize (205 and 388 applied pollen.cm⁻²) suffered a significantly higher mortality rate (68 and 85% respectively) compared to larvae feeding on leaves with no pollen (11%), or feeding on leaves with pollen from conventional maize (6 to 25%). At lower Bt maize pollen doses (23-104 applied pollen.cm⁻²),mortality ranged from 11-25% and there were no apparent differences among treatments. The corresponding LC₅₀-and LC₉₀-values for neonate larvae of the Peacock butterfly were 187 and 448 applied pollen grains.cm⁻² of Bt-176, respectively.Weight of larvae surviving consumption of Bt-176 maize pollen declined between 10 and 81% with increased pollen doses (r = -0.95). The highest weight reduction (81%) corresponded to the highest pollen concentration (388 pollen grains applied.cm⁻²). Ingestion of pollen from the conventional maize hybrid did not

  6. Transgenic Alfalfa Plants Expressing the Sweetpotato Orange Gene Exhibit Enhanced Abiotic Stress Tolerance

    Science.gov (United States)

    Wang, Zhi; Ke, Qingbo; Kim, Myoung Duck; Kim, Sun Ha; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Park, Woo Sung; Ahn, Mi-Jeong; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Lee, Sang-Hoon; Lim, Yong Pyo; Kwak, Sang-Soo

    2015-01-01

    Alfalfa (Medicago sativa L.), a perennial forage crop with high nutritional content, is widely distributed in various environments worldwide. We recently demonstrated that the sweetpotato Orange gene (IbOr) is involved in increasing carotenoid accumulation and enhancing resistance to multiple abiotic stresses. In this study, in an effort to improve the nutritional quality and environmental stress tolerance of alfalfa, we transferred the IbOr gene into alfalfa (cv. Xinjiang Daye) under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter through Agrobacterium tumefaciens-mediated transformation. Among the 11 transgenic alfalfa lines (referred to as SOR plants), three lines (SOR2, SOR3, and SOR8) selected based on their IbOr transcript levels were examined for their tolerance to methyl viologen (MV)-induced oxidative stress in a leaf disc assay. The SOR plants exhibited less damage in response to MV-mediated oxidative stress and salt stress than non-transgenic plants. The SOR plants also exhibited enhanced tolerance to drought stress, along with higher total carotenoid levels. The results suggest that SOR alfalfa plants would be useful as forage crops with improved nutritional value and increased tolerance to multiple abiotic stresses, which would enhance the development of sustainable agriculture on marginal lands. PMID:25946429

  7. Overexpression of PSP1 enhances growth of transgenic Arabidopsis plants under ambient air conditions.

    Science.gov (United States)

    Han, Xiaofang; Peng, Keli; Wu, Haixia; Song, Shanshan; Zhu, Yerong; Bai, Yanling; Wang, Yong

    2017-07-01

    The importance of the phosphorylated pathway (PPSB) of L-serine (Ser) biosynthesis in plant growth and development has been demonstrated, but its specific role in leaves and interaction with photorespiration, the main leaf Ser biosynthetic pathway at daytime, are still unclear. To investigate whether changes in biosynthesis of Ser by the PPSB in leaves could have an impact on photorespiration and plant growth, we overexpressed PSP1, the last enzyme of this pathway, under control of the Cauliflower Mosaic Virus 35S promoter in Arabidopsis thaliana. Overexpressor plants grown in normal air displayed larger rosette diameter and leaf area as well as higher fresh and dry weight than the wild type. By contrast, no statistically significant differences to the wild type were observed when the overexpressor seedlings were transferred to elevated CO2, indicating a relationship between PSP1 overexpression and photorespiration. Additionally, the transgenic plants displayed higher photorespiration, an increase in CO2 net-uptake and stronger expression in the light of genes encoding enzymes involved in photorespiration. We further demonstrated that expression of many genes involved in nitrogen assimilation was also promoted in leaves of transgenic plants and that leaf nitrate reductase activity increased in the light, too, although not in the dark. Our results suggest a close correlation between the function of PPSB and photorespiration, and also nitrogen metabolism in leaves.

  8. Transgenic alfalfa plants expressing the sweetpotato Orange gene exhibit enhanced abiotic stress tolerance.

    Directory of Open Access Journals (Sweden)

    Zhi Wang

    Full Text Available Alfalfa (Medicago sativa L., a perennial forage crop with high nutritional content, is widely distributed in various environments worldwide. We recently demonstrated that the sweetpotato Orange gene (IbOr is involved in increasing carotenoid accumulation and enhancing resistance to multiple abiotic stresses. In this study, in an effort to improve the nutritional quality and environmental stress tolerance of alfalfa, we transferred the IbOr gene into alfalfa (cv. Xinjiang Daye under the control of an oxidative stress-inducible peroxidase (SWPA2 promoter through Agrobacterium tumefaciens-mediated transformation. Among the 11 transgenic alfalfa lines (referred to as SOR plants, three lines (SOR2, SOR3, and SOR8 selected based on their IbOr transcript levels were examined for their tolerance to methyl viologen (MV-induced oxidative stress in a leaf disc assay. The SOR plants exhibited less damage in response to MV-mediated oxidative stress and salt stress than non-transgenic plants. The SOR plants also exhibited enhanced tolerance to drought stress, along with higher total carotenoid levels. The results suggest that SOR alfalfa plants would be useful as forage crops with improved nutritional value and increased tolerance to multiple abiotic stresses, which would enhance the development of sustainable agriculture on marginal lands.

  9. Field resistance to Fusarium oxysporum and Verticillium dahliae in transgenic cotton expressing the plant defensin NaD1.

    Science.gov (United States)

    Gaspar, Yolanda M; McKenna, James A; McGinness, Bruce S; Hinch, Jillian; Poon, Simon; Connelly, Angela A; Anderson, Marilyn A; Heath, Robyn L

    2014-04-01

    The plant defensin NaD1, from Nicotiana alata, has potent antifungal activity against a range of filamentous fungi including the two important cotton pathogens, Fusarium oxysporum f. sp. vasinfectum (Fov) and Verticillium dahliae. Transgenic cotton plants expressing NaD1 were produced and plants from three events were selected for further characterization. Homozygous plants were assessed in greenhouse bioassays for resistance to Fov. One line (D1) was selected for field trial testing over three growing seasons in soils naturally infested with Fov and over two seasons in soils naturally infested with V. dahliae. In the field trials with Fov-infested soil, line D1 had 2-3-times the survival rate, a higher tolerance to Fov (higher disease rank), and a 2-4-fold increase in lint yield compared to the non-transgenic Coker control. When transgenic line D1 was planted in V. dahliae-infested soil, plants had a higher tolerance to Verticillium wilt and up to a 2-fold increase in lint yield compared to the non-transgenic Coker control. Line D1 did not exhibit any detrimental agronomic features compared to the parent Coker control when plants were grown in non-diseased soil. This study demonstrated that the expression of NaD1 in transgenic cotton plants can provide substantial resistance to two economically important fungal pathogens.

  10. Ectopically expressed leaf and bulb lectins from garlic (Allium sativum L.) protect transgenic tobacco plants against cotton leafworm (Spodoptera littoralis).

    Science.gov (United States)

    Sadeghi, Amin; Smagghe, Guy; Broeders, Sylvia; Hernalsteens, Jean-Pierre; De Greve, Henri; Peumans, Willy J; Van Damme, Els J M

    2008-02-01

    The insecticidal activity of the leaf (ASAL) and bulb (ASAII) agglutinins from Allium sativum L. (garlic) against the cotton leafworm, Spodoptera littoralis Boisd. (Lepidoptera: Noctuidae) was studied using transgenic tobacco plants expressing the lectins under the control of the constitutive CaMV35S promoter. PCR analysis confirmed that the garlic lectin genes were integrated into the plant genome. Western blots and semi-quantitative agglutination assays revealed lectin expression at various levels in the transgenic lines. Biochemical analyses indicated that the recombinant ASAL and ASAII are indistinguishable from the native garlic lectins. Insect bioassays using detached leaves from transgenic tobacco plants demonstrated that the ectopically expressed ASAL and ASAII significantly (P transgenic approach.

  11. Histochemical evaluation of catechins in PEG stressed transgenic tea plants using catechin-specific-diazotized sulfanilamide reagent.

    Science.gov (United States)

    Bhattacharya, A; Sharma, M; Gulati, A; Joshi, R; Chanda, S K; Ahuja, P S

    2015-01-01

    We investigated the applicability of catechin-specific-reagent (CSR) for histochemical evaluation of catechins. The diazotized arylamine moiety in CSR reacts specifically with the A-ring of catechins to yield a golden yellow complex. This makes it highly specific for spectrophotometric quantification of catechins. Therefore, microtome cut sections of untransformed and osmotin-expressing transgenic leaves and stem of tea were stained with CSR. We found catechins in the form of golden yellow globules. The catechin globules increased in the structurally intact and highly turgid cells of osmotin expressing transgenic tea plants after stress treatment with 20% PEG; by contrast, the cells in non-transgenic plants accumulated fewer catechin globules. Spectrophotometric quantification of catechins also confirmed higher levels in transgenics compared to untransformed plants. We found elevated accumulation of catechins in stress tolerant cells of tea leaves.

  12. Obtention of papaya var. Maradol Roja transgenic plants with delay in the fruits ripening

    Directory of Open Access Journals (Sweden)

    Orelvis Portal

    2003-04-01

    Full Text Available Papaya is a crop of economic importance for tropical countries. However, post-harvesting losses of Maradol Roja cultivar, the most important in Central America, have been up to 80%, due to a lack of proper infrastructure and qualified personnel at the rural areas and mainly because of the quick ripening of the fruits. The ripening process in climacteric fruits like papaya is regulated by ethylene levels. By reducing the genetic expression of the key enzymes which participate in the biosynthesis of this phytohormone, a decrease of the expression could be obtained. With the purpose of obtaining transgenic plants with delayed fruit ripening, accox1 gene encoding for the 1-aminoiciclopropeno-1-carboxylate (ACC oxidase of the Maradol Roja variety was isolated and a binary vector for gene gun mediated transformation constructed with this gene in antisense orientation. In vitro transgenic lines, verified by PCR, were obtained. Key words: antisense technology, Carica papaya, ethylene, ripening

  13. No adverse effects of transgenic maize on population dynamics of endophytic Bacillus subtilis strain B916-gfp.

    Science.gov (United States)

    Sun, Chongsi; Geng, Lili; Wang, Meiling; Shao, Gaoxiang; Liu, Yongfeng; Shu, Changlong; Zhang, Jie

    2017-02-01

    Endophytic bacterial communities play a key role in promoting plant growth and combating plant diseases. However, little is known about their population dynamics in plant tissues and bulk soil, especially in transgenic crops. This study investigated the colonization of transgenic maize harboring the Bacillus thuringiensis (Bt) cry1Ah gene by Bacillus subtilis strain B916-gfp present in plant tissues and soil. Bt and nontransgenic maize were inoculated with B916-gfp by seed soaking, or root irrigation under both laboratory greenhouse and field conditions. During the growing season, B916-gfp colonized transgenic as well as nontransgenic plants by both inoculation methods. No differences were observed in B916-gfp population size between transgenic and nontransgenic plants, except at one or two time points in the roots and stems that did not persist over the examination period. Furthermore, planting transgenic maize did not affect the number of B916-gfp in bulk soil in either laboratory or field trials. These results indicate that transgenic modification of maize with the cry1Ah gene has no influence on colonization by the endophytic bacteria B916-gfp present in the plant and in bulk soil. © 2016 The Authors. MicrobiologyOpenpublished by John Wiley & Sons Ltd.

  14. Plant β-1,3-glucanases: their biological functions and transgenic expression against phytopathogenic fungi.

    Science.gov (United States)

    Balasubramanian, Vaiyapuri; Vashisht, Divya; Cletus, Jean; Sakthivel, Natarajan

    2012-11-01

    β-1,3-Glucanases are abundant in plants and have been characterized from a wide range of species. They play key roles in cell division, trafficking of materials through plasmodesmata, in withstanding abiotic stresses and are involved in flower formation through to seed maturation. They also defend plants against fungal pathogens either alone or in association with chitinases and other antifungal proteins. They are grouped in the PR-2 family of pathogenesis-related (PR) proteins. Use of β-1,3-glucanase genes as transgenes in combination with other antifungal genes is a plausible strategy to develop durable resistance in crop plants against fungal pathogens. These genes, sourced from alfalfa, barley, soybean, tobacco, and wheat have been co-expressed along with other antifungal proteins, such as chitinases, peroxidases, thaumatin-like proteins and α-1-purothionin, in various crop plants with promising results that are discussed in this review.

  15. [Antimicrobial activities of ant Ponericin W1 against plant pathogens in vitro and the disease resistance in its transgenic Arabidopsis].

    Science.gov (United States)

    Chen, Yong-Fang; Sun, Peng-Wei; Tang, Ding-Zhong

    2013-08-01

    The antimicrobial peptides (AMPs) exhibit a broad antimicrobial spectrum. The application of AMPs from non-plant organisms attracts considerable attention in plant disease resistance engineering. Ponericin W1, isolated from the venom of ant (Pachycondyla goeldii), shows antimicrobial activities against Gram-positive bacteria, Gram-negative bacteria and the budding yeast (Saccharomyces cerevisiae); however, it is not clear whether Ponericin W1 is effective against plant pathogens. The results of this study indicated synthesized Ponericin W1 inhibited mycelial growth of Magnaporthe oryzae and Botrytis cinerea, as well as hyphal growth and spore production of Fusarium graminearum. Besides, Ponericin W1 exhibited antibacterial activities against Pseudomonas syringae pv. tomato and Xanthomonas oryzae pv. oryzae. After codon optimization, Ponericin W1 gene was constructed into plant expression vector, and transformed into Arabidopsis thaliana by floral dip method. The Ponericin W1 was located in intercellular space of the transgenic plants as expected. Compared with the wild-type plants, there were ungerminated spores and less hyphal, conidia on the leaves of transgenic plants after innoculation with the powdery mildew fungus Golovinomyces cichoracearum. After innoculation with the pathogenic bac-terium Pseudomonas syringae pv. tomato, the baceria in the leaves of transgenic plants was significantly less than the wild-type plants, indicating that the transgenic plants displayed enhanced disease resistance to pathogens. These results demonstrate a potential use of Ponericin W1 in genetic engineering for broad-spectrum plant disease resistance.

  16. A promoter derived from taro bacilliform badnavirus drives strong expression in transgenic banana and tobacco plants.

    Science.gov (United States)

    Yang, I C; Iommarini, J P; Becker, D K; Hafner, G J; Dale, J L; Harding, R M

    2003-08-01

    Taro bacilliform virus (TaBV) is a pararetrovirus of the genus Badnavirus which infects the monocotyledonous plant, taro ( Colocasia esculenta). A region of the TaBV genome spanning nucleotides 6,281 to 12 (T1200), including the 3' end of open reading frame 3 (ORF 3) and the intergenic region to the end of the tRNA(met)-binding site, was tested for promoter activity along with four different 5' deletion fragments (T600, T500, T250 and T100). In transient assays, only the T1200, T600, T500 fragments were shown to have promoter activity in taro leaf, banana suspension cells and tobacco callus. When these three promoters were evaluated in stably transformed, in vitro-grown transgenic banana and tobacco plants, all were found to drive near-constitutive expression of either the green fluorescent protein or beta-glucuronidase (GUS) reporter gene in the stem (or pseudostem), leaves and roots, with strongest expression observed in the vascular tissue. In transgenic banana leaves, the T600 promoter directed four-fold greater GUS activity than that of the T1200, T500 and the maize polyubiquitin-1 promoters. In transgenic tobacco leaves, the levels of GUS expression directed by the three promoters was between four- and ten-fold lower than that of the double Cauliflower mosaic virus 35S promoter. These results indicate that the TaBV-derived promoters may be useful for the high-level constitutive expression of transgenes in either monocotyledonous or dicotyledonous species.

  17. Altered expression of pyrophosphate: fructose-6-phosphate 1-phosphotransferase affects the growth of transgenic Arabidopsis plants.

    Science.gov (United States)

    Lim, Hyemin; Cho, Man-Ho; Jeon, Jong-Seong; Bhoo, Seong Hee; Kwon, Yong-Kook; Hahn, Tae-Ryong

    2009-06-30

    Pyrophosphate: fructose-6-phosphate 1-phosphotransferase (PFP) catalyzes the reversible interconversion of fructose-6-phosphate and fructose-1,6-bisphosphate, a key step in the regulation of the metabolic flux toward glycolysis or gluconeogenesis. To examine the role of PFP in plant growth, we have generated transgenic Arabidopsis plants that either overexpress or repress Arabidopsis PFP sub-unit genes. The overexpressing lines displayed increased PFP activity and slightly faster growth relative to wild type plants, although their photosynthetic activities and the levels of metabolites appeared not to have significantly changed. In contrast, the RNAi lines showed significantly retarded growth in parallel with the reduced PFP activity. Analysis of photosynthetic activity revealed that the growth retardation phenotype of the RNAi lines was accompanied by the reduced rates of CO(2) assimilation. Microarray analysis of our transgenic plants further revealed that the altered expression of AtPFPbeta affects the expression of several genes involved in diverse physiological processes. Our current data thus suggest that PFP is important in carbohydrate metabolism and other cellular processes.

  18. The status of RNAi-based transgenic research in plant nematology

    Directory of Open Access Journals (Sweden)

    Tushar Kanti Dutta

    2015-01-01

    Full Text Available With the understanding of nematode-plant interactions at the molecular level, new avenues for engineering resistance have opened up, with RNA interference being one of them. Induction of RNAi by delivering double-stranded RNA (dsRNA has been very successful in the model non-parasitic nematode, Caenorhabditis elegans, while in plant nematodes, dsRNA delivery has been accomplished by soaking nematodes with dsRNA solution mixed with synthetic neurostimulants. The success of in vitro RNAi of target genes has inspired the use of in planta delivery of dsRNA to feeding nematodes. The most convincing success of host-delivered RNAi has been achieved against root-knot nematodes. Plant-mediated RNAi has been shown to lead to the specific down-regulation of target genes in invading nematodes, which had a profound effect on nematode development. RNAi-based transgenics are advantageous as they do not produce any functional foreign proteins and target organisms in a sequence-specific manner. Although the development of RNAi-based transgenics against plant nematodes is still in the preliminary stage, they offer novel management strategy for the future.

  19. Effects of mti-2 Transgenic Potato Plants on the Aphid Myzus persicae (Sternorrhyncha: Aphididae

    Directory of Open Access Journals (Sweden)

    Julien Saguez

    2010-01-01

    Full Text Available Overexpressed in transgenic plants, protease inhibitors showed insecticidal effects against several insect taxa. We transformed potato internodes with the mustard trypsin inhibitor mti-2 gene. Among the 35 independent transgenic potato lines obtained via Agrobacterium tumefasciens transformation, four (DM6, DM7, DM11, and DM19 were selected for their high level of MTI-2 (at least to 30% of trypsin activity inhibition. Feeding assays were carried out to evaluate their effects on the green-peach aphid, Myzus persicae (Sternorrhyncha: Aphididae. Prereproductive period, nymphal mortality, adult fecundity, and doubling time of M. persicae populations were monitored on nontransformed potato plants (NT and the four selected DM lines. Compared to NT plants, DM19 did not induce any effect on M. persicae. In contrast, DM7 and DM11 increased nymphal survival by approximately 20%. DM6 and DM11 lines slightly enhanced M. persicae daily fecundity and intrinsic rate of natural increase, leading to a reduction of the doubling time of the populations by 1 day. DM6 did not impact nymphal mortality, whereas with the DM11 almost all the nymphs survived. Potato plants transformed with the mti-2 gene variably affected the life history of M. persicae but did not show any insecticidal effect on the aphid.

  20. Biochemical and functional characterization of anti-HIV antibody-ELP fusion proteins from transgenic plants.

    Science.gov (United States)

    Floss, Doreen M; Sack, Markus; Stadlmann, Johannes; Rademacher, Thomas; Scheller, Jürgen; Stöger, Eva; Fischer, Rainer; Conrad, Udo

    2008-05-01

    The stability and recovery of recombinant proteins expressed in plants are improved by fusion to elastin-like peptides (ELPs). In order to test the suitability of ELP for the production of pharmaceutical proteins, transgenic plants were created that individually expressed the light and heavy chains of the broadly neutralizing anti-human immunodeficiency virus type 1 (anti-HIV-1) monoclonal antibody 2F5, which is being evaluated as a microbicide component. The antibody chains were expressed both with and without a C-terminal ELP fusion. Crossing these plants in all combinations resulted in transgenic lines producing the full antibody in four formats, with ELP on either the light or heavy chains, on both or on neither. Characterization of the affinity-purified antibodies by surface plasmon resonance spectroscopy showed that the kinetic binding parameters were identical to those of a Chinese hamster ovary (CHO) cell counterpart lacking ELP. N-Glycan analysis showed that all four derivatives contained predominantly oligo-mannose-type N-glycans and that the ELP fusions had no significant effect on N-glycan structure. It was concluded that ELP fusion to the light chain, heavy chain or both chains of a plant-derived antibody had no adverse affects on protein quality, but had a positive impact on the yield. ELP fusions do not interfere with folding, assembly, trafficking in the secretory pathway or post-translational modification, but enhance stability whilst at the same time simplifying recovery.

  1. Improvement of salt tolerance in transgenic potato plants by glyceraldehyde-3 phosphate dehydrogenase gene transfer.

    Science.gov (United States)

    Jeong, M J; Park, S C; Byun, M O

    2001-10-31

    In the previous experiment, we isolated and characterized glyceraldehyde-3-phosphate dehydrogenase (GPD) gene of the oyster mushroom, Pleurotus sajor-caju. Expression levels of the GPD gene in the mycelia of P sajor-caju was significantly increased by exposing the mycelia to abiotic stresses, such as salt, cold, heat, and drought. We also showed that GPD confers abiotic stress resistance when introduced into yeast cells. The survival rate of the transgenic yeast cell that harbored the GPD gene was significantly higher when the yeast cells were subjected to salt, cold, heat, and drought stresses, compared with the yeast that was transformed with the pYES2 vector alone. In order to investigate the functional role of the P. sajor-caju GPD gene in higher plant cells, the complete P. sajor-caju GPD cDNA was fused into the CaMV35S promoter and then introduced into potato plants. Putative potato transformants were screened by using PCR. Twenty-one transformants were further analyzed with RT-PCR to confirm the expression of P. sajor-caju GPD. A RT-PCR Southern blot analysis revealed that 12 transgenics induced the P. sajor-caju GPD gene expression. A bioassay of these transformants revealed that the P. sajor-caju GPD gene was enough to confer salt stress resistance in the potato plant cell system. Results showed that P. sajor-caju GPD, which was continuously expressed in transgenic potato plants under normal growing conditions, resulted in improved tolerance against salt loading.

  2. Chimeric cDNA Sequences from Citrus tristeza virus Confer RNA Silencing-Mediated Resistance in Transgenic Nicotiana benthamiana Plants.

    Science.gov (United States)

    Roy, Gourgopal; Sudarshana, Mysore R; Ullman, Diane E; Ding, Shou-Wei; Dandekar, Abhaya M; Falk, Bryce W

    2006-08-01

    ABSTRACT RNA silencing has been shown to be an important mechanism for conferring resistance in transgenic, virus-resistant plants. We used this approach to evaluate resistance in Nicotiana benthamiana plants transformed with chimeric coding and noncoding sequences from Citrus tristeza virus (CTV). Several independent transgenic plant lines were generated, using two constructs (pCTV1 and pCTV2) designed to produce self-complementary transcripts. The pCTV1 contained cDNA sequences from the CTV capsid protein (CP), p20, and 3' untranslated region (UTR); and pCTV2 contained CP, p23, and 3' UTR sequences. Heterologous recombinant Potato virus X (PVX) containing either homologous or heterologous CTV sequences was used to challenge plants and resistance was evaluated phenotypically and validated with reverse-transcriptase polymerase chain reaction and northern hybridization analysis. Transgenic plants (T1 generation) for each construct showed resistance to recombinant PVX constructs used for challenge experiments when PVX contained p20 or UTR (for CTV1 plants), or p23 or UTR (for CTV2 plants). However, no resistance was seen when plants were challenged with PVX containing the CTV CP. T2 generation plants also showed resistance even when challenged with PVX containing the cognate CTV sequences obtained from heterologous CTV isolates. The presence of transgene-specific small interfering RNAs in the resistant CTV1 and CTV2 plants indicated that resistance was mediated by post-transcriptional gene silencing.

  3. GC-rich coding sequences reduce transposon-like, small RNA-mediated transgene silencing.

    Science.gov (United States)

    Sidorenko, Lyudmila V; Lee, Tzuu-Fen; Woosley, Aaron; Moskal, William A; Bevan, Scott A; Merlo, P Ann Owens; Walsh, Terence A; Wang, Xiujuan; Weaver, Staci; Glancy, Todd P; Wang, PoHao; Yang, Xiaozeng; Sriram, Shreedharan; Meyers, Blake C

    2017-10-30

    The molecular basis of transgene susceptibility to silencing is poorly characterized in plants; thus, we evaluated several transgene design parameters as means to reduce heritable transgene silencing. Analyses of Arabidopsis plants with transgenes encoding a microalgal polyunsaturated fatty acid (PUFA) synthase revealed that small RNA (sRNA)-mediated silencing, combined with the use of repetitive regulatory elements, led to aggressive transposon-like silencing of canola-biased PUFA synthase transgenes. Diversifying regulatory sequences and using native microalgal coding sequences (CDSs) with higher GC content improved transgene expression and resulted in a remarkable trans-generational stability via reduced accumulation of sRNAs and DNA methylation. Further experiments in maize with transgenes individually expressing three crystal (Cry) proteins from Bacillus thuringiensis (Bt) tested the impact of CDS recoding using different codon bias tables. Transgenes with higher GC content exhibited increased transcript and protein accumulation. These results demonstrate that the sequence composition of transgene CDSs can directly impact silencing, providing design strategies for increasing transgene expression levels and reducing risks of heritable loss of transgene expression.

  4. EVALUATION OF BIOASSAYS FOR TESTING Bt SWEETPOTATO ...

    African Journals Online (AJOL)

    ACSS

    2013-07-24

    Jul 24, 2013 ... bioassays used were: (i) 1st instar larva in an artificial diet using root powder of transgenic events, (ii) whole root of transgenic events infested with ... On established plants, adult weevils attack leaves while the larvae feed ... the efficacy of transgenic events with genes expressing Cry toxins, which present.

  5. A promoter from sugarcane bacilliform badnavirus drives transgene expression in banana and other monocot and dicot plants.

    Science.gov (United States)

    Schenk, P M; Sagi, L; Remans, T; Dietzgen, R G; Bernard, M J; Graham, M W; Manners, J M

    1999-04-01

    A 1369 bp DNA fragment (Sc) was isolated from a full-length clone of sugarcane bacilliform badnavirus (ScBV) and was shown to have promoter activity in transient expression assays using monocot (banana, maize, millet and sorghum) and dicot plant species (tobacco, sunflower, canola and Nicotiana benthamiana). This promoter was also tested for stable expression in transgenic banana and tobacco plants. These experiments showed that this promoter could drive high-level expression of the beta-glucuronidase (GUS) reporter gene in most plant cells. The expression level was comparable to the maize ubiquitin promoter in standardised transient assays in maize. In transgenic banana plants the expression levels were variable for different transgenic lines but was generally comparable with the activities of both the maize ubiquitin promoter and the enhanced cauliflower mosaic virus (CaMV) 35S promoter. The Sc promoter appears to express in a near-constitutive manner in transgenic banana and tobacco plants. The promoter from sugarcane bacilliform virus represents a useful tool for the high-level expression of foreign genes in both monocot and dicot transgenic plants that could be used similarly to the CaMV 35S or maize polyubiquitin promoter.

  6. Haploid technology allows for the efficient and rapid generation of homozygous antibody-accumulating transgenic tobacco plants.

    Science.gov (United States)

    Floss, Doreen M; Kumlehn, Jochen; Conrad, Udo; Saalbach, Isolde

    2009-09-01

    The large-scale production of plant-derived recombinant proteins requires the breeding of lines homozygous for the transgene(s). These can be selected by progeny testing over multiple sexual generations, but a more efficient means is to fix homozygosity in a single generation using doubled haploid technology. In this study, transgenic tobacco plants, hemizygous for both of the independently inherited genes encoding the light and heavy chains of the anti-human immunodeficiency virus monoclonal antibody 2F5, were used to establish embryogenic pollen cultures. The improved protocol employed in this study guaranteed a very high regeneration efficiency, with more than 50% of the regenerants being spontaneously doubled haploids. Hence, there was no requirement to chemically induce chromosome doubling to recover sufficient entirely homozygous recombinants. As expected, approximately 25% of the regenerants were homozygous for both transgenes. Thus, the employment of haploid technology allowed for the efficient and rapid generation of true-breeding tobacco lines accumulating functional immunoglobulins.

  7. Expression of Beta-glucosidase increases trichome density and artemisinin content in transgenic Artemisia annua plants

    Science.gov (United States)

    Singh, Nameirakpam Dolendro; Kumar, Shashi; Daniell, Henry

    2015-01-01

    Artemisinin is highly effective against multidrug-resistant strains of Plasmodium falciparum, the etiological agent of the most severe form of malaria. However, a low level of accumulation of artemisinin in Artemisia annua is a major limitation for its production and delivery to malaria endemic areas of the world. While several strategies to enhance artemisinin have been extensively explored, enhancing storage capacity in trichome has not yet been considered. Therefore, trichome density was increased with the expression of β glucosidase (bgl1) gene in A. annua through Agrobacterium-mediated transformation. Transgene (bgl1) integration and transcript was confirmed by molecular analysis. Trichome density increased up to 20% in leaves and 66% in flowers of BGL1 transgenic plants than Artemisia control plants. High-performance liquid chromatography (HPLC, MS-TOF) data showed that artemisinin content increased up to 1.4% in leaf and 2.56% in flowers (g-1DW), similar to the highest yields achieved so far through metabolic engineering. Artemisinin was enhanced up to 5-fold in BGL1 transgenic flowers. The present study opens the possibility of increasing artemisinin content by manipulating trichomes density, which is a major reservoir of artemisinin. Combining biosynthetic pathway engineering with enhancing trichome density may further increase artemisinin yield in A. annua. Because oral feeding of Artemisia plant cells reduced parasitemia more efficiently than the purified drug, reduced drug resistance and cost of prohibitively expensive purification process, enhanced expression should play a key role in making this valuable drug affordable to treat malaria in a large global population that disproportionally impacts low-socioeconomic areas and underprivileged children. PMID:26360801

  8. Genetic engineering of the biosynthesis of glycinebetaine leads to increased tolerance of photosynthesis to salt stress in transgenic tobacco plants.

    Science.gov (United States)

    Yang, Xinghong; Liang, Zheng; Wen, Xiaogang; Lu, Congming

    2008-01-01

    Genetically engineered tobacco (Nicotiana tabacum L.) with the ability to synthesis glycinebetaine (GB) in chloroplasts was established by introducing the BADH gene for betaine aldehyde dehydrogenase from spinach (Spinacia oleracea L.). The genetic engineering resulted in enhanced tolerance of growth of young seedlings to salt stress. This increased tolerance was not due to improved water status, since there were no significant differences in accumulation of sodium and chloride, leaf water potential, and relative water content between wild type and transgenic plants under salt stress. Salt stress resulted in a decrease in CO2 assimilation and such a decrease was much greater in wild type plants than in transgenic plants. Though salt stress showed no damage to PSII, there were a decrease in the maximal PSII electron transport rate in vivo and an increase in non-photochemical quenching (NPQ) and these changes were greater in wild type plants than in transgenic plants. In addition, salt stress inhibited the activities of ribulose 1,5-bisphosphate carboxylase/oxygenase, chloroplastic fructose-1,6-bisphosphatase, fructose-1,6-bisphosphate aldolase, and phosphoribulokinase and such a decrease was also greater in wild type plants than in transgenic plants, suggesting that GB protects these enzymes against salt stress. However, there were no significant changes in the activities of phosphoglycerate kinase, triose phosphate isomerase, ribulose-5-phosphate isomerase, transketolase, and sedoheptulose-1,7-bisphosphatase in both wild type and transgenic plants. The results in this study suggest that enhanced tolerance of CO2 assimilation to salt stress may be one of physiological bases for increased tolerance of growth of transgenic plants to salt stress.

  9. Generation of transgenic plantain (Musa spp.) with resistance to plant pathogenic nematodes.

    Science.gov (United States)

    Roderick, Hugh; Tripathi, Leena; Babirye, Annet; Wang, Dong; Tripathi, Jaindra; Urwin, Peter E; Atkinson, Howard J

    2012-10-01

    Plant parasitic nematodes impose a severe constraint on plantain and banana productivity; however, the sterile nature of many cultivars precludes conventional breeding for resistance. Transgenic plantain cv. Gonja manjaya (Musa AAB) plants, expressing a maize cystatin that inhibits nematode digestive cysteine proteinases and a synthetic peptide that disrupts nematode chemoreception, were assessed for their ability to resist nematode infection. Lines were generated that expressed each gene singly or both together in a stacked defence. Nematode challenge with a single species or a mixed population identified 10 lines with significant resistance. The best level of resistance achieved against the major pest species Radopholus similis was 84% ± 8% for the cystatin, 66% ± 14% for the peptide and 70% ± 6% for the dual defence. In the mixed population, trial resistance was also demonstrated to Helicotylenchus multicinctus. A fluorescently labelled form of the chemodisruptive peptide underwent retrograde transport along certain sensory dendrites of R. similis as required to disrupt chemoreception. The peptide was degraded after 30 min in simulated intestinal fluid or boiling water and after 1 h in nonsterile soil. In silico sequence analysis suggests that the peptide is not a mammalian antigen. This work establishes the mode of action of a novel nematode defence, develops the evidence for its safe and effective deployment against multiple nematode species and identifies transgenic plantain lines with a high level of resistance for a proposed field trial. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

  10. Ectopic accumulation of linalool confers resistance to Xanthomonas citri subsp. citri in transgenic sweet orange plants.

    Science.gov (United States)

    Shimada, Takehiko; Endo, Tomoko; Rodríguez, Ana; Fujii, Hiroshi; Goto, Shingo; Matsuura, Takakazu; Hojo, Yuko; Ikeda, Yoko; Mori, Izumi C; Fujikawa, Takashi; Peña, Leandro; Omura, Mitsuo

    2017-05-01

    In order to clarify whether high linalool content in citrus leaves alone induces strong field resistance to citrus canker caused by Xanthomonas citri subsp. citri (Xcc), and to assess whether this trait can be transferred to a citrus type highly sensitive to the bacterium, transgenic 'Hamlin' sweet orange (Citrus sinensis L. Osbeck) plants over-expressing a linalool synthase gene (CuSTS3-1) were generated. Transgenic lines (LIL) with the highest linalool content showed strong resistance to citrus canker when spray inoculated with the bacterium. In LIL plants inoculated by wounding (multiple-needle inoculation), the linalool level was correlated with the repression of the bacterial titer and up-regulation of defense-related genes. The exogenous application of salicylic acid, methyl jasmonate or linalool triggered responses similar to those constitutively induced in LIL plants. The linalool content in Ponkan mandarin leaves was significantly higher than that of leaves from six other representative citrus genotypes with different susceptibilities to Xcc. We propose that linalool-mediated resistance might be unique to citrus tissues accumulating large amounts of volatile organic compounds in oil cells. Linalool might act not only as a direct antibacterial agent, but also as a signal molecule involved in triggering a non-host resistance response against Xcc. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. PERSPECTIVES OF THE DEVELOPMENT OF MUCOSAL VACCINES AGAINST DANGEROUS INFECTIONS ON THE BASE OF TRANSGENIC PLANTS

    Directory of Open Access Journals (Sweden)

    A.V. Tretyakova

    2012-08-01

    Full Text Available Mucosal vaccines created on the base of transgenic plants reacting with mucosal layers of the intestines and other organs are considered to be the perspective method of the vaccination. These vaccines induce both mucosal and general humoral immunogenicity after the peroral administration. The folding of antigenic proteins synthesizing in plants occurs via eukaryotic type and has advantages before yeast and prokaryotic platforms. This feature results to more adequate synthesis of antibodies against pathogens and to the interaction with effector molecules of complement. Earlier we together with The State Scientific Center “Vector”, Institute of chemical biology and fundamental medicine SB RAS and Dr R.Hammond from Laboratory of Plant Pathology (Maryland, USA created two candidate vaccines : one of them against AIDS (HIV-1 and hepatitis B on the base of the chimeric gene TBI-HBS, encoding simultaneously 9 antigenic determinants of HIV-1 and the main surface antigen of hepatitis B (HBsAg. The second candidate vaccine was created against hepatitis B on the base of the genetic construct with the gene preS2-S encoding the synthesis of two subunits of the main surface antigen of hepatitis B and the signal peptide HDEL which directed antigens for the accumulation on ER. Both vaccines were tested on mice and confirmed their immunogenicity as the pronounced antibodies response. Twice vaccinated mice maintained the antibodies response during 11 months after there was little tendency to lowering. It was established that transgenic plants – vaccines (tomato kept the capability to the synthesis of antigenic determinants in seven seed generations during 7 years. The results of the development of the mucosal vaccine against cervical carcinoma (carcinoma of uterine cervix evoked by human papillomaviruses of high oncogenic risks were presented in this report. We created the genetic construct consisting of 35S CaMV promoter, Ώ (omega leader of TMV, the

  12. Bioassay of estrogenic compounds in transgenic Arabidopsis plants carrying a recombinant human estrogen receptor gene and a GFP reporter gene.

    Science.gov (United States)

    Inui, Hideyuki; Sasaki, Hideaki; Chua, Nam-Hai; Ohkawa, Hideo

    2009-12-01

    Transgenic Arabidopsis plants carrying a recombinant human estrogen receptor gene and a green fluorescent protein reporter gene were used to bioassay estrogenic compounds. We constructed four recombinant human estrogen receptor genes by combining the DNA-binding domain of LexA, a synthetic nuclear localization signal, a ligand-binding domain of the human estrogen receptor, and a transactivation domain of VP16 in different orders; the XEV plants were the most sensitive, and were able to detect 0.001 ng ml(-1) of 17ss-estradiol (E(2)). The transgenic plants absorbed E(2) and 4-nonylphenol present in the nutrient solution, whereas most of the other compounds seemed to be retained in, or on, the roots. Estrone, methoxychlor, bisphenol A, 4-nonylphenol, and 4-t-octylphenol in the medium were clearly detected by RT-PCR and PCR of the genomic DNA. The transgenic Arabidopsis XEV plants thus have potential for the bioassay of estrogenic compounds.

  13. Field resistance to Fusarium oxysporum and Verticillium dahliae in transgenic cotton expressing the plant defensin NaD1

    OpenAIRE

    Gaspar, Yolanda M.; McKenna, James A.; McGinness, Bruce S.; Hinch, Jillian; Poon, Simon; Connelly, Angela A.; Anderson, Marilyn A.; Heath, Robyn L.

    2014-01-01

    The plant defensin NaD1, from Nicotiana alata, has potent antifungal activity against a range of filamentous fungi including the two important cotton pathogens, Fusarium oxysporum f. sp. vasinfectum (Fov) and Verticillium dahliae. Transgenic cotton plants expressing NaD1 were produced and plants from three events were selected for further characterization. Homozygous plants were assessed in greenhouse bioassays for resistance to Fov. One line (D1) was selected for field trial testing over thr...

  14. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    Science.gov (United States)

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-07-27

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects.

  15. Defence-related gene expression in transgenic lemon plants producing an antimicrobial Trichoderma harzianum endochitinase during fungal infection.

    Science.gov (United States)

    Distefano, Gaetano; La Malfa, Stefano; Vitale, Alessandro; Lorito, Matteo; Deng, Ziniu; Gentile, Alessandra

    2008-10-01

    Constitutive over-expression of antifungal genes from microorganisms involved in plant defence mechanisms represents a promising strategy for conferring genetic resistance against a broad range of plant pathogenic fungi. In the present work, two transgenic lemon clones with the chit42 gene from Trichoderma harzianum were tested for resistance to fungal disease and expression level of defence-related genes was evaluated. Different resistance-related processes, such as production of reactive oxygen species (ROS), systemic acquired resistance (SAR) and induced systemic resistance (ISR), were monitored in transgenic and wild type lemon clones inoculated with Botrytis cinerea, the causal agent of grey mould in citrus. Expression of genes that encode gluthatione peroxidase (GPX), a producer of ROS, chitinases, glucanases (SAR), PAL, HPL, and AOS (ISR) was measured by quantitative PCR during the first 24 h after leaf inoculation. Leaves of transgenic lemon plants inoculated with B. cinerea showed significantly less lesion development than wild type leaves. Tissues from detached leaves of different transgenic lemon clones showed a significant correlation between resistance and transgene expression. On the other hand, the over-expression of the transgenic fungal gene enhanced by two-three folds transcript levels of genes associated with enhanced ROS production and ISR establishment, while the expression of native chitinase and glucanase genes involved in SAR was down-regulated.

  16. Engineering the production of sugar alcohols in transgenic plants: Extending the limits of photosynthesis. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-31

    In the different tobacco lines expressing different polyols, the authors have investigated how the presence of polyols affects ion uptake during short periods of stress. In addition, they began investigations on recovery from short periods of stress, e.g. eight days of drought and/or five days in 400 mM NaCl. The transgenic plants take up sodium more slowly. The next set of experiments, modeled after the experiments done with Mesembryanthemum will investigate ion transport and partitioning in control and transgenic tobacco. Photosynthetic activities of drought-stressed mannitol/ononitrol tobacco were investigated. Measurements of fluorescence, carbon fixation rates and electron transport indicated that the polyol-containing plants loose photosynthetic competence more slowly than controls. Transfer of the mtlD gene (mannitol production) into Arabidopsis has been accomplished. The transgenic plants are phenotypically normal. They survive 300 mM NaCl when the stress is started when the plants are mature--in contrast to wild type which is killed at 150 mM. Seeds from mannitol-containing plants germinate (100%) in 100 mM NaCl while germination rate of wild type is about 20%. In 200 mM NaCl n wild type germinates, while in some transgenic lines still 50% of the seeds germinated. At 250 mM NaCl during germination, the transgenic seeds are severely impaired, only 10 to 20% begin germination.

  17. Promoters for pregenomic RNA of banana streak badnavirus are active for transgene expression in monocot and dicot plants.

    Science.gov (United States)

    Schenk, P M; Remans, T; Sági, L; Elliott, A R; Dietzgen, R G; Swennen, R; Ebert, P R; Grof, C P; Manners, J M

    2001-10-01

    Two putative promoters from Australian banana streak badnavirus (BSV) isolates were analysed for activity in different plant species. In transient expression systems the My (2105 bp) and Cv (1322 bp) fragments were both shown to have promoter activity in a wide range of plant species including monocots (maize, barley, banana, millet, wheat, sorghum), dicots (tobacco, canola, sunflower, Nicotiana benthamiana, tipu tree), gymnosperm (Pinus radiata) and fern (Nephrolepis cordifolia). Evaluation of the My and Cv promoters in transgenic sugarcane, banana and tobacco plants demonstrated that these promoters could drive high-level expression of either the green fluorescent protein (GFP) or the beta-glucuronidase (GUS) reporter gene (uidA) in vegetative plant cells. In transgenic sugarcane plants harbouring the Cv promoter, GFP expression levels were comparable or higher (up to 1.06% of total soluble leaf protein as GFP) than those of plants containing the maize ubiquitin promoter (up to 0.34% of total soluble leaf protein). GUS activities in transgenic in vitro-grown banana plants containing the My promoter were up to seven-fold stronger in leaf tissue and up to four-fold stronger in root and corm tissue than in plants harbouring the maize ubiquitin promoter. The Cv promoter showed activities that were similar to the maize ubiquitin promoter in in vitro-grown banana plants, but was significantly reduced in larger glasshouse-grown plants. In transgenic in vitro-grown tobacco plants, the My promoter reached activities close to those of the 35S promoter of cauliflower mosaic virus (CaMV), while the Cv promoter was about half as active as the CaMV 35S promoter. The BSV promoters for pregenomic RNA represent useful tools for the high-level expression of foreign genes in transgenic monocots.

  18. Tolerance of transgenic canola plants (Brassica napus) amended with plant growth-promoting bacteria to flooding stress at a metal-contaminated field site

    Energy Technology Data Exchange (ETDEWEB)

    Farwell, Andrea J. [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada)]. E-mail: afarwell@sciborg.uwaterloo.ca; Vesely, Susanne [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Nero, Vincent [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Rodriguez, Hilda [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); McCormack, Kimberley [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Shah, Saleh [Alberta Research Council, Vegreville, Alberta T9C 1T4 (Canada); Dixon, D. George [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada); Glick, Bernard R. [Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada)

    2007-06-15

    The growth of transgenic canola (Brassica napus) expressing a gene for the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase was compared to non-transformed canola exposed to flooding and elevated soil Ni concentration, in situ. In addition, the ability of the plant growth-promoting bacterium Pseudomonas putida UW4, which also expresses ACC deaminase, to facilitate the growth of non-transformed and transgenic canola under the above mentioned conditions was examined. Transgenic canola and/or canola treated with P. putida UW4 had greater shoot biomass compared to non-transformed canola under low flood-stress conditions. Under high flood-stress conditions, shoot biomass was reduced and Ni accumulation was increased in all instances relative to low flood-stress conditions. This is the first field study to document the increase in plant tolerance utilizing transgenic plants and plant growth-promoting bacteria exposed to multiple stressors. - Using transgenic plants and plant growth-promoting bacteria as phytoremediation methods increased plant tolerance at a metal-contaminated field site under low flood conditions.

  19. Similar genetic basis of resistance to Bt toxin Cry1Ac in Boll-selected and diet-selected strains of pink bollworm.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Fabrick

    Full Text Available Genetically engineered cotton and corn plants producing insecticidal Bacillus thuringiensis (Bt toxins kill some key insect pests. Yet, evolution of resistance by pests threatens long-term insect control by these transgenic Bt crops. We compared the genetic basis of resistance to Bt toxin Cry1Ac in two independently derived, laboratory-selected strains of a major cotton pest, the pink bollworm (Pectinophora gossypiella [Saunders]. The Arizona pooled resistant strain (AZP-R was started with pink bollworm from 10 field populations and selected with Cry1Ac in diet. The Bt4R resistant strain was started with a long-term susceptible laboratory strain and selected first with Bt cotton bolls and later with Cry1Ac in diet. Previous work showed that AZP-R had three recessive mutations (r1, r2, and r3 in the pink bollworm cadherin gene (PgCad1 linked with resistance to Cry1Ac and Bt cotton producing Cry1Ac. Here we report that inheritance of resistance to a diagnostic concentration of Cry1Ac was recessive in Bt4R. In interstrain complementation tests for allelism, F(1 progeny from crosses between AZP-R and Bt4R were resistant to Cry1Ac, indicating a shared resistance locus in the two strains. Molecular analysis of the Bt4R cadherin gene identified a novel 15-bp deletion (r4 predicted to cause the loss of five amino acids upstream of the Cry1Ac-binding region of the cadherin protein. Four recessive mutations in PgCad1 are now implicated in resistance in five different strains, showing that mutations in cadherin are the primary mechanism of resistance to Cry1Ac in laboratory-selected strains of pink bollworm from Arizona.

  20. Study of effects of Bt maize (Zea mays) events on Lepidoptera Ostrinia nubilalis, Sesamia nonagrioidesin southwestern France.

    Science.gov (United States)

    Folcher, L; Eychenne, N; Weissenberger, A; Jarry, M; Regnault-Roger, C; Delos, M

    2006-01-01

    Crops of maize (Zea mays L.) were conducted in southwestern France with GMO (Genetic Modified Organism) vs isogenetic varieties in order to verify the control of European Corn Borer (ECB) Ostrinia nubilalis (Hübner) and the Corn Stalk Borer (CBS) Sesamia nonagrioides (Lefevbre) by GMO in field conditions. The bioassays were carried out in 1998 and 1999 before moratorium, then in 2005. Experiments involved respectively 18, 12 and 19 fields cultivated with Furio/Furio cb (GMO), Cecilia/ Elgina (GMO) and PR33P66/PR33P67 (GMO) varieties. These transgenic events expressed Cry1A(b) protein (Bt maize). Plants were noted for insect infestation assessment (number of larvae in stalks and ears per plant). Statistical tests used t-test on couple of plots. Results showed a significant difference in the density of both ECB and CBS between control and the two transgenic events. The two transgenic events acted differently. The control of the two Bt events on the two pests were differentiated and discussed. These experiments underlined the importance of field evaluation for testing real effects of transgenic events on crop according the environmental context.

  1. IT-BT convergence technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    This book explains IT-BT convergence technology as the future technology, which includes a prolog, easy IT-BT convergence technology that has infinite potentials for new value, policy of IT-BT convergence technology showing the potential of smart Korea, IT-BT convergence opening happy future, for the new future of IT powerful nation Korea with IT-BT convergence technology and an epilogue. This book reveals the conception, policy, performance and future of IT-BT convergence technology.

  2. Agrobacterium tumefaciens mediated transformation of Orychophragmus violaceus cotyledon and regeneration of transgenic plants.

    Science.gov (United States)

    Zhou, J; Wei, Z; Xu, Z; Liu, S; Luo, P

    1996-01-01

    Excised cotyledons of Orychophragmus violaceus were used as explants for tissue culture. They were cultured on the MS medium supplemented with BA (3 mg/L) and NAA (0.2 mg/L). When the regenerated buds were 2 cm long, they were excised and transferred onto 1/2 MS medium with IBA (0.03 mg/L), then the whole plants were regenerated. The frequency of plant regeneration was 100%. Subsequently, the genetic transformation of O. violaceus was studied. After 2-3 days of cocultivation with Agrobacterium tumefaciens strain A208se (pTiT37, pROA93), the cotyledons were transferred onto the selection medium containing 25 mg/L Km and 250 mg/L Ap. After shoots emerged, they were excised and transferred onto the rooting medium containing 25 mg/L Km and 100 mg/L Cef. The roots were formed within 4-5 weeks. The whole plants were transplanted into pots and grew well. The frequency of plant regeneration was about 51%. The regenerated plants showed high enzymatic activities of beta-glucuronidase and neomycine phosphotransferase II. Southern blot analysis confirmed that NPTII gene had been stably integrated into the chromosomal genome of O. violaceus. The transformation frequency was 5.6%. The first transgenic plant of O. violaceus is being reported.

  3. A Critical Review of the Concept of Transgenic Plants: Insights into Pharmaceutical Biotechnology and Molecular Farming.

    Science.gov (United States)

    Abiri, Rambod; Valdiani, Alireza; Maziah, Mahmood; Shaharuddin, Noor Azmi; Sahebi, Mahbod; Yusof, Zetty Norhana Balia; Atabaki, Narges; Talei, Daryush

    2016-01-01

    Using transgenic plants for the production of high-value recombinant proteins for industrial and clinical applications has become a promising alternative to using conventional bioproduction systems, such as bacteria, yeast, and cultured insect and animal cells. This novel system offers several advantages over conventional systems in terms of safety, scale, cost-effectiveness, and the ease of distribution and storage. Currently, plant systems are being utilised as recombinant bio-factories for the expression of various proteins, including potential vaccines and pharmaceuticals, through employing several adaptations of recombinant processes and utilizing the most suitable tools and strategies. The level of protein expression is a critical factor in plant molecular farming, and this level fluctuates according to the plant species and the organs involved. The production of recombinant native and engineered proteins is a complicated procedure that requires an inter- and multi-disciplinary effort involving a wide variety of scientific and technological disciplines, ranging from basic biotechnology, biochemistry, and cell biology to advanced production systems. This review considers important plant resources, affecting factors, and the recombinant-protein expression techniques relevant to the plant molecular farming process.

  4. Enhancement of production of eugenol and its glycosides in transgenic aspen plants via genetic engineering.

    Science.gov (United States)

    Koeduka, Takao; Suzuki, Shiro; Iijima, Yoko; Ohnishi, Toshiyuki; Suzuki, Hideyuki; Watanabe, Bunta; Shibata, Daisuke; Umezawa, Toshiaki; Pichersky, Eran; Hiratake, Jun

    2013-06-21

    Eugenol, a volatile phenylpropene found in many plant species, exhibits antibacterial and acaricidal activities. This study attempted to modify the production of eugenol and its glycosides by introducing petunia coniferyl alcohol acetyltransferase (PhCFAT) and eugenol synthase (PhEGS) into hybrid aspen. Gas chromatography analyses revealed that wild-type hybrid aspen produced small amount of eugenol in leaves. The heterologous overexpression of PhCFAT alone resulted in up to 7-fold higher eugenol levels and up to 22-fold eugenol glycoside levels in leaves of transgenic aspen plants. The overexpression of PhEGS alone resulted in a subtle increase in either eugenol or eugenol glycosides, and the overexpression of both PhCFAT and PhEGS resulted in significant increases in the levels of both eugenol and eugenol glycosides which were nonetheless lower than the increases seen with overexpression of PhCFAT alone. On the other hand, overexpression of PhCFAT in transgenic Arabidopsis and tobacco did not cause any synthesis of eugenol. These results indicate that aspen leaves, but not Arabidopsis and tobacco leaves, have a partially active pathway to eugenol that is limited by the level of CFAT activity and thus the flux of this pathway can be increased by the introduction of a single heterologous gene. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Purification and characterization of a viral chitinase active against plant pathogens and herbivores from transgenic tobacco.

    Science.gov (United States)

    Di Maro, Antimo; Terracciano, Irma; Sticco, Lucia; Fiandra, Luisa; Ruocco, Michelina; Corrado, Giandomenico; Parente, Augusto; Rao, Rosa

    2010-05-03

    The Autographa californica nucleopolyhedrovirus chitinase A (AcMNPV ChiA) is a chitinolytic enzyme with fungicidal and insecticidal properties. Its expression in transgenic plants enhances resistance against pests and fungal pathogens. We exploited tobacco for the production of a biologically active recombinant AcMNPV ChiA (rChiA), as such species is an alternative to traditional biological systems for large-scale enzyme production. The protein was purified from leaves using ammonium sulfate precipitation followed by anion exchange and gel-filtration chromatography. Transgenic plants produced an estimated 14 mg kg(-1) fresh leaf weight, which represents 0.2% of total soluble proteins. The yield of the purification was about 14% (2 mg kg(-1) fresh leaf weight). The comparison between the biochemical and kinetic properties of the rChiA with those of a commercial Serratia marcescens chitinase A indicated that the rChiA was thermostable and more resistant at basic pH, two positive features for agricultural and industrial applications. Finally, we showed that the purified rChiA enhanced the permeability of the peritrophic membrane of larvae of two Lepidoptera (Bombyx mori and Heliothis virescens) and inhibited spore germination and growth of the phytopatogenic fungus Alternaria alternata. The data indicated that tobacco represents a suitable platform for the production of rChiA, an enzyme with interesting features for future applications as "eco-friendly" control agent in agriculture. Published by Elsevier B.V.

  6. Expression of plant sweet protein brazzein in the milk of transgenic mice.

    Directory of Open Access Journals (Sweden)

    Sen Yan

    Full Text Available Sugar, the most popular sweetener, is essential in daily food. However, excessive sugar intake has been associated with several lifestyle-related diseases. Finding healthier and more economical alternatives to sugars and artificial sweeteners has received increasing attention to fulfill the growing demand. Brazzein, which comes from the pulp of the edible fruit of the African plant Pentadiplandra brazzeana Baill, is a protein that is 2,000 times sweeter than sucrose by weight. Here we report the production of transgenic mice that carry the optimized brazzein gene driven by the goat Beta-casein promoter, which specifically directs gene expression in the mammary glands. Using western blot analysis and immunohistochemistry, we confirmed that brazzein could be efficiently expressed in mammalian milk, while retaining its sweetness. This study presents the possibility of producing plant protein-sweetened milk from large animals such as cattle and goats.

  7. Transgenic rice plants expressing a modified cry1Ca1 gene are resistant to Spodoptera litura and Chilo suppressalis.

    Science.gov (United States)

    Zaidi, Mohsin Abbas; Ye, Gongyin; Yao, Hongwei; You, Taek H; Loit, Evelin; Dean, Donald H; Riazuddin, Sheikh; Altosaar, Illimar

    2009-11-01

    Nucleotide sequence encoding the truncated insecticidal Cry1Ca1 protein from Bacillus thuringiensis was extensively modified based on the codon usage of rice genes. The overall G + C contents of the synthetic cry1Ca1 coding sequence were raised to 65% with an additional bias of enriching for G and C ending codons as preferred by monocots. The synthetic gene was introduced into the Chinese japonica variety, Xiushui 11, by Agrobacterium-mediated transformation. Transgenic rice plants harboring this gene were highly resistant to Chilo suppressalis and Spodoptera litura larvae as revealed by insect bioassays. High levels of Cry1Ca1 protein were obtained in the leaves of transgenic rice, which were effective in achieving 100% mortality of S. litura and C. suppressalis larvae. The levels of Cry1Ca1 expression in the leaves of these transgenic plants were up to 0.34% of the total soluble proteins. The larvae of C. suppressalis and S. litura could consume a maximum of 1.89 and 4.89 mm2 of transgenic leaf area whereas the consumption of nontransgenic leaves by these larvae was significantly higher; 58.33 and 61.22 mm2, respectively. Analysis of R1 transgenic plants indicated that the cry1Ca1 was inherited by the progeny plants and provided complete protection against C. suppressalis and S. litura larvae.

  8. Expression of rice thaumatin-like protein gene in transgenic banana plants enhances resistance to fusarium wilt.

    Science.gov (United States)

    Mahdavi, F; Sariah, M; Maziah, M

    2012-02-01

    The possibility of controlling Fusarium wilt--caused by Fusarium oxysporum sp. cubensec (race 4)--was investigated by genetic engineering of banana plants for constitutive expression of rice thaumatin-like protein (tlp) gene. Transgene was introduced to cauliflower-like bodies' cluster, induced from meristemic parts of male inflorescences, using particle bombardment with plasmid carrying a rice tlp gene driving by the CaMV 35S promoter. Hygromycin B was used as the selection reagent. The presence and integration of rice tlp gene in genomic DNA confirmed by PCR and Southern blot analyses. RT-PCR revealed the expression of transgene in leaf and root tissues in transformants. Bioassay of transgenic banana plants challenged with Fusarium wilt pathogen showed that expression of TLP enhanced resistance to F. oxysporum sp. cubensec (race 4) compared to control plants.

  9. Generation of transgenic plants expressing plasma membrane-bound antibodies to the environmental pollutant microcystin-LR.

    Science.gov (United States)

    Barbi, Tommaso; Drake, Pascal M W; Drever, Matthew; van Dolleweerd, Craig J; Porter, Andrew R; Ma, Julian K-C

    2011-06-01

    In this paper we describe the engineering and regeneration of transgenic tobacco plants expressing a recombinant plasma membrane-retained antibody specific to microcystin-LR (MC-LR), the environmental toxin pollutant produced by cyanobacteria. The antibody was created by a genetic fusion of the antigen binding regions of the microcystin-specific single chain antibody, 3A8, with the constant regions from the murine IgG1κ, Guy's 13, including a membrane retention sequence at the C-terminal end of the antibody heavy chain. The antibody produced in the leaves was shown to be functional by binding to MC-LR in an ELISA with antibody yields in transgenic plant leaves reaching a maximum of 1.2 μg g(-1) leaf f.wt (0.005% total soluble protein). Antibody-MC-LR complexes formed in leaves after addition of MC-LR to hydroponic medium around the roots of transgenic plant cultures.

  10. Response to metal stress of Nicotiana langsdorffii plants wild-type and transgenic for the rat glucocorticoid receptor gene.

    Science.gov (United States)

    Fuoco, Roger; Bogani, Patrizia; Capodaglio, Gabriele; Del Bubba, Massimo; Abollino, Ornella; Giannarelli, Stefania; Spiriti, Maria Michela; Muscatello, Beatrice; Doumett, Saer; Turetta, Clara; Zangrando, Roberta; Zelano, Vincenzo; Buiatti, Marcello

    2013-05-01

    Recently our findings have shown that the integration of the gene coding for the rat gluco-corticoid receptor (GR receptor) in Nicotiana langsdorffii plants induced morphophysiological effects in transgenic plants through the modification of their hormonal pattern. Phytohormones play a key role in plant responses to many different biotic and abiotic stresses since a modified hormonal profile up-regulates the activation of secondary metabolites involved in the response to stress. In this work transgenic GR plants and isogenic wild type genotypes were exposed to metal stress by treating them with 30ppm cadmium(II) or 50ppm chromium(VI). Hormonal patterns along with changes in key response related metabolites were then monitored and compared. Heavy metal up-take was found to be lower in the GR plants. The transgenic plants exhibited higher values of S-abscisic acid (S-ABA) and 3-indole acetic acid (IAA), salicylic acid and total polyphenols, chlorogenic acid and antiradical activity, compared to the untransformed wild type plants. Both Cd and Cr treatments led to an increase in hormone concentrations and secondary metabolites only in wild type plants. Analysis of the results suggests that the stress responses due to changes in the plant's hormonal system may derive from the interaction between the GR receptor and phytosteroids, which are known to play a key role in plant physiology and development. Copyright © 2013 Elsevier GmbH. All rights reserved.

  11. Simultaneous Expression of PDH45 with EPSPS Gene Improves Salinity and Herbicide Tolerance in Transgenic Tobacco Plants

    Science.gov (United States)

    Garg, Bharti; Gill, Sarvajeet S.; Biswas, Dipul K.; Sahoo, Ranjan K.; Kunchge, Nandkumar S.; Tuteja, Renu; Tuteja, Narendra

    2017-01-01

    To cope with the problem of salinity- and weed-induced crop losses, a multi-stress tolerant trait is need of the hour but a combinatorial view of such traits is not yet explored. The overexpression of PDH45 (pea DNA helicase 45) and EPSPS (5-enoylpruvyl shikimate-3-phosphate synthase) genes have been reported to impart salinity and herbicide tolerance. Further, the understanding of mechanism and pathways utilized by PDH45 and EPSPS for salinity and herbicide tolerance will help to improve the crops of economical importance. In the present study, we have performed a comparative analysis of salinity and herbicide tolerance to check the biochemical parameters and antioxidant status of tobacco transgenic plants. Collectively, the results showed that PDH45 overexpressing transgenic lines display efficient tolerance to salinity stress, while PDH45+EPSPS transgenics showed tolerance to both the salinity and herbicide as compared to the control [wild type (WT) and vector control (VC)] plants. The activities of the components of enzymatic antioxidant machinery were observed to be higher in the transgenic plants indicating the presence of an efficient antioxidant defense system which helps to cope with the stress-induced oxidative-damages. Photosynthetic parameters also showed significant increase in PDH45 and PDH45+EPSPS overexpressing transgenic plants in comparison to WT, VC and EPSPS transgenic plants under salinity stress. Furthermore, PDH45 and PDH45+EPSPS synergistically modulate the jasmonic acid and salicylic acid mediated signaling pathways for combating salinity stress. The findings of our study suggest that pyramiding of the PDH45 gene with EPSPS gene renders host plants tolerant to salinity and herbicide by enhancing the antioxidant machinery thus photosynthesis. PMID:28392794

  12. Vast potential for using the piggyBac transposon to engineer transgenic plants at specific genomic locations

    Science.gov (United States)

    Johnson, Eric T.; Owens, Jesse B.; Moisyadi, Stefan

    2016-01-01

    ABSTRACT The acceptance of bioengineered plants by some nations is hampered by a number of factors, including the random insertion of a transgene into the host genome. Emerging technologies, such as site-specific nucleases, are enabling plant scientists to promote recombination or mutations at specific plant loci. Off target activity of these nucleases may limit widespread use. Insertion of transgenes by transposases engineered with a specific DNA binding domain has been accomplished in a number of organisms, but not in plants. The piggyBac transposon system, originally isolated from an insect, has been utilized to transform a variety of organisms. The piggyBac transposase is amendable to structural modifications, and was able to insert a transgene at a specific human locus through fusion of a DNA binding domain to its N-terminus. Recent developments demonstrating the activity of piggyBac transposase in plants is an important first step toward the potential use of engineered versions of piggyBac transposase for site-specific transgene insertion in plants. PMID:26930269

  13. Controversy Associated With the Common Component of Most Transgenic Plants – Kanamycin Resistance Marker Gene

    Directory of Open Access Journals (Sweden)

    Srećko Jelenić

    2003-01-01

    Full Text Available Plant genetic engineering is a powerful tool for producing crops resistant to pests, diseases and abiotic stress or crops with improved nutritional value or better quality products. Currently over 70 genetically modified (GM crops have been approved for use in different countries. These cover a wide range of plant species with significant number of different modified traits. However, beside the technology used for their improvement, the common component of most GM crops is the neomycin phosphotransferase II gene (nptII, which confers resistance to the antibiotics kanamycin and neomycin. The nptII gene is present in GM crops as a marker gene to select transformed plant cells during the first steps of the transformation process. The use of antibiotic-resistance genes is subject to controversy and intense debate, because of the likelihood that clinical therapy could be compromised due to inactivation of the oral dose of the antibiotic from consumption of food derived from the transgenic plant, and because of the risk of gene transfer from plants to gut and soil microorganisms or to consumer’s cells. The present article discusses these possibilities in the light of current scientific knowledge.

  14. Broad-scale suppression of cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae), associated with Bt cotton crops in Northern New South Wales, Australia.

    Science.gov (United States)

    Baker, G H; Tann, C R

    2017-04-01

    The cotton bollworm, Helicoverpa armigera, is a major pest of many agricultural crops in several countries, including Australia. Transgenic cotton, expressing a single Bt toxin, was first used in the 1990s to control H. armigera and other lepidopteran pests. Landscape scale or greater pest suppression has been reported in some countries using this technology. However, a long-term, broad-scale pheromone trapping program for H. armigera in a mixed cropping region in eastern Australia caught more moths during the deployment of single Bt toxin cotton (Ingard®) (1996-2004) than in previous years. This response can be attributed, at least in part, to (1) a precautionary cap (30% of total cotton grown, by area) being applied to Ingard® to restrict the development of Bt resistance in the pest, and (2) during the Ingard® era, cotton production greatly increased (as did that of another host plant, sorghum) and H. armigera (in particular the 3rd and older generations) responded in concert with this increase in host plant availability. However, with the replacement of Ingard® with Bollgard II® cotton (containing two different Bt toxins) in 2005, and recovery of the cotton industry from prevailing drought, H. armigera failed to track increased host-plant supply and moth numbers decreased. Greater toxicity of the two gene product, introduction of no cap on Bt cotton proportion, and an increase in natural enemy abundance are suggested as the most likely mechanisms responsible for the suppression observed.

  15. Development of marker-free transgenic Jatropha plants with increased levels of seed oleic acid

    Directory of Open Access Journals (Sweden)

    Qu Jing

    2012-02-01

    Full Text Available Abstract Background Jatropha curcas is recognized as a new energy crop due to the presence of the high amount of oil in its seeds that can be converted into biodiesel. The quality and performance of the biodiesel depends on the chemical composition of the fatty acids present in the oil. The fatty acids profile of the oil has a direct impact on ignition quality, heat of combustion and oxidative stability. An ideal biodiesel composition should have more monounsaturated fatty acids and less polyunsaturated acids. Jatropha seed oil contains 30% to 50% polyunsaturated fatty acids (mainly linoleic acid which negatively impacts the oxidative stability and causes high rate of nitrogen oxides emission. Results The enzyme 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (FAD2 is the key enzyme responsible for the production of linoleic acid in plants. We identified three putative delta 12 fatty acid desaturase genes in Jatropha (JcFAD2s through genome-wide analysis and downregulated the expression of one of these genes, JcFAD2-1, in a seed-specific manner by RNA interference technology. The resulting JcFAD2-1 RNA interference transgenic plants showed a dramatic increase of oleic acid (> 78% and a corresponding reduction in polyunsaturated fatty acids (Jatropha had around 37% oleic acid and 41% polyunsaturated fatty acids. This indicates that FAD2-1 is the major enzyme responsible for converting oleic acid to linoleic acid in Jatropha. Due to the changes in the fatty acids profile, the oil of the JcFAD2-1 RNA interference seed was estimated to yield a cetane number as high as 60.2, which is similar to the required cetane number for conventional premium diesel fuels (60 in Europe. The presence of high seed oleic acid did not have a negative impact on other Jatropha agronomic traits based on our preliminary data of the original plants under greenhouse conditions. Further, we developed a marker-free system to generate the transgenic Jatropha

  16. Hairpin RNA derived from viral NIa gene confers immunity to wheat streak mosaic virus infection in transgenic wheat plants.

    Science.gov (United States)

    Fahim, Muhammad; Ayala-Navarrete, Ligia; Millar, Anthony A; Larkin, Philip J

    2010-09-01

    Wheat streak mosaic virus (WSMV), vectored by Wheat curl mite, has been of great economic importance in the Great Plains of the United States and Canada. Recently, the virus has been identified in Australia, where it has spread quickly to all major wheat growing areas. The difficulties in finding adequate natural resistance in wheat prompted us to develop transgenic resistance based on RNA interference (RNAi). An RNAi construct was designed to target the nuclear inclusion protein 'a' (NIa) gene of WSMV. Wheat was stably cotransformed with two plasmids: pStargate-NIa expressing hairpin RNA (hpRNA) including WSMV sequence and pCMneoSTLS2 with the nptII selectable marker. When T(1) progeny were assayed against WSMV, ten of sixteen families showed complete resistance in transgenic segregants. The resistance was classified as immunity by four criteria: no disease symptoms were produced; ELISA readings were as in uninoculated plants; viral sequences could not be detected by RT-PCR from leaf extracts; and leaf extracts failed to give infections in susceptible plants when used in test-inoculation experiments. Southern blot hybridization analysis indicated hpRNA transgene integrated into the wheat genome. Moreover, accumulation of small RNAs derived from the hpRNA transgene sequence positively correlated with immunity. We also showed that the selectable marker gene nptII segregated independently of the hpRNA transgene in some transgenics, and therefore demonstrated that it is possible using these techniques, to produce marker-free WSMV immune transgenic plants. This is the first report of immunity in wheat to WSMV using a spliceable intron hpRNA strategy.

  17. Remote sensing of gene expression in Planta: transgenic plants as monitors of exogenous stress perception in extraterrestrial environments

    Science.gov (United States)

    Manak, Michael S.; Paul, Anna-Lisa; Sehnke, Paul C.; Ferl, Robert J.

    2002-01-01

    Transgenic arabidopsis plants containing the alcohol dehydrogenase (Adh) gene promoter fused to the green fluorescent protein (GFP) reporter gene were developed as biological sensors for monitoring physiological responses to unique environments. Plants were monitored in vivo during exposure to hypoxia, high salt, cold, and abcissic acid in experiments designed to characterize the utility and responses of the Adh/GFP biosensors. Plants in the presence of environmental stimuli that induced the Adh promoter responded by expressing GFP, which in turn generated a detectable fluorescent signal. The GFP signal degraded when the inducing stimulus was removed. Digital imaging of the Adh/GFP plants exposed to each of the exogenous stresses demonstrated that the stress-induced gene expression could be followed in real time. The experimental results established the feasibility of using a digital monitoring system for collecting gene expression data in real time from Transgenic Arabidopsis Gene Expression System (TAGES) biosensor plants during space exploration experiments.

  18. Total Soluble Protein Extraction for Improved Proteomic Analysis of Transgenic Rice Plant Roots.

    Science.gov (United States)

    Raorane, Manish L; Narciso, Joan O; Kohli, Ajay

    2016-01-01

    With the advent of high-throughput platforms, proteomics has become a powerful tool to search for plant gene products of agronomic relevance. Protein extractions using multistep protocols have been shown to be effective to achieve better proteome profiles than simple, single-step extractions. These protocols are generally efficient for above ground tissues such as leaves. However, each step leads to loss of some amount of proteins. Additionally, compounds such as proteases in the plant tissues lead to protein degradation. While protease inhibitor cocktails are available, these alone do not seem to suffice when roots are included in the plant sample. This is obvious given the lack of high molecular weight (HMW) proteins obtained from samples that include root tissue. For protein/proteome analysis of transgenic plant roots or of seedlings, which include root tissue, such pronounced protein degradation is especially undesirable. A facile protein extraction protocol is presented, which ensures that despite the inclusion of root tissues there is minimal loss in total protein components.

  19. Dominant inheritance of field-evolved resistance to Bt corn in Busseolafusca.

    Directory of Open Access Journals (Sweden)

    Pascal Campagne

    Full Text Available Transgenic crops expressing Bacillus thuringiensis (Bt toxins have been adopted worldwide, notably in developing countries. In spite of their success in controlling target pests while allowing a substantial reduction of insecticide use, the sustainable control of these pest populations is threatened by the evolution of resistance. The implementation of the "high dose/refuge" strategy for managing insect resistance in transgenic crops aims at delaying the evolution of resistance to Bt crops in pest populations by promoting survival of susceptible insects. However, a crucial condition for the "high dose/refuge" strategy to be efficient is that the inheritance of resistance should be functionally recessive. Busseolafusca developed high levels of resistance to the Bt toxin Cry 1Ab expressed in Bt corn in South Africa. To test whether the inheritance of B. fusca resistance to the Bt toxin could be considered recessive we performed controlled crosses with this pest and evaluated its survival on Bt and non-Bt corn. Results show that resistance of B. fusca to Bt corn is dominant, which refutes the hypothesis of recessive inheritance. Survival on Bt corn was not lower than on non-Bt corn for both resistant larvae and the F1 progeny from resistant × susceptible parents. Hence, resistance management strategies of B. fusca to Bt corn must address non-recessive resistance.

  20. USING OF Agrobacterium-MEDIATED TRANSFORMATION FOR THE BIOTECHNOLOGICAL IMPROVEMENT OF COMPOSITAE PLANTS. ІІ. SYNTHESIS OF BIOACTIVE COMPOUNDS IN TRANSGENIC PLANTS AND «HAIRY» ROOTS

    Directory of Open Access Journals (Sweden)

    N. A. Matvieieva

    2015-04-01

    Full Text Available The review focused on the data concerning current state in the field of Compositae “hairy” roots and transgenic plants construction using A.tumefaciens- and A. rhizogenes-mediated transformation to obtain biologically active compounds, including recombinant proteins. The article presents data on the results of genetic transformation of Cichorium intybus, Lactuca sativa, Artemisia annua, Artemisia vulgaris, Calendula officinalis, Withania somnifera and other Compositae plants as well as studies on the artemisinin, flavonoids, polyphenols, fructans and other compounds accumulation in transgenic plants and roots. The data show that the use of biotechnological approaches for construction of "hairy" roots and transgenic plants with new features are of great interest. The possibility of increase in the accumulation of naturally synthesized bioactive compounds and recombinant proteins production via A. tumefaciens and A. rhizogenes-mediated transformation have been shown. In vitro cultivation of transgenic plants characterized by high level of bioactive compounds accumulation and synthesis of recombinant proteins makes it possible to obtain guaranteed pure raw material. Using of biotechnological approaches preserved natural populations of plants is particularly important for rare and endangered plant species.

  1. Breeding and Characterization of a New Rice Restorer Line Containing Bt Gene

    Directory of Open Access Journals (Sweden)

    Fang-yuan GAO

    2009-09-01

    Full Text Available Bt5198, a new rice restorer line containing Bt gene, was developed from the cross and backcross of the elite restorer line Chenghui 177 with Bt Minghui 63, a transgenic Bt restorer line. The inbred lines were evaluated using PCR amplification, test paper evaluation, insect resistance evaluation in both the laboratory and paddy fields, nursery evaluation of rice blast resistance and pedigree selection of agronomic traits. Larval mortalities on Bt5198 and Bt Minghui 63 were 100% when rice culms were inoculated with the eggs of the striped stem borer (SSB in the laboratory. Bt5198 was highly resistant against SSB and the yellow stem borer (YSB under field conditions. The F1 hybrids derived from Bt5198 and four cytoplasmic male sterile (CMS lines were also highly resistant to SSB and YSB and had a significant heterosis. Two-year evaluation of rice blast resistance confirmed that the resistance levels of Bt5198 to leaf blast and neck blast were similar to those of Chenghui 177 and significantly better than those of Bt Minghui 63. Seed germination ability and pollen yield of Bt5198 were similar with Chenghui 177, suggesting that the introduction of the Bt gene into the new restorer line had no significant effects on seed vitality or the yield of seed production. To identify the presence of the Bt gene, it was effective to combine test paper examination with the evaluation of insect-resistance, both in the laboratory and under field conditions.

  2. Feeding and dispersal behavior of the cotton leafworm, Alabama argillacea (Hübner) (Lepidoptera: Noctuidae), on Bt and non-Bt cotton: implications for evolution and resistance management.

    Science.gov (United States)

    Ramalho, Francisco S; Pachú, Jéssica K S; Lira, Aline C S; Malaquias, José B; Zanuncio, José C; Fernandes, Francisco S

    2014-01-01

    The host acceptance of neonate Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) larvae to Bt cotton plants exerts a strong influence on the potential risk that this pest will develop resistance to Bt cotton. This will also determine the efficiency of management strategies to prevent its resistance such as the "refuge-in-the-bag" strategy. In this study, we assessed the acceptance of neonate A. argillacea larvae to Bt and non-Bt cotton plants at different temperatures during the first 24 h after hatching. Two cotton cultivars were used in the study, one a Bt DP 404 BG (Bollgard) cultivar, and the other, an untransformed isoline, DP 4049 cultivar. There was a greater acceptance by live neonate A. argillacea larvae for the non-Bt cotton plants compared with the Bt cotton plants, especially in the time interval between 18 and 24 h. The percentages of neonate A. argillacea larvae found on Bt or non-Bt plants were lower when exposed to temperatures of 31 and 34 °C. The low acceptance of A. argillacea larvae for Bt cotton plants at high temperatures stimulated the dispersion of A. argillacea larvae. Our results support the hypothesis that the dispersion and/or feeding behavior of neonate A. argillacea larvae is different between Bt and non-Bt cotton. The presence of the Cry1Ac toxin in Bt cotton plants, and its probable detection by the A. argillacea larvae tasting or eating it, increases the probability of dispersion from the plant where the larvae began. These findings may help to understand how the A. argillacea larvae detect the Cry1Ac toxin in Bt cotton and how the toxin affects the dispersion behavior of the larvae over time. Therefore, our results are extremely important for the management of resistance in populations of A. argillacea on Bt cotton.

  3. Transgenic banana plants expressing Xanthomonas wilt resistance genes revealed a stable non-target bacterial colonization structure.

    Science.gov (United States)

    Nimusiima, Jean; Köberl, Martina; Tumuhairwe, John Baptist; Kubiriba, Jerome; Staver, Charles; Berg, Gabriele

    2015-12-10

    Africa is among the continents where the battle over genetically modified crops is currently being played out. The impact of GM in Africa could potentially be very positive. In Uganda, researchers have developed transgenic banana lines resistant to banana Xanthomonas wilt. The transgenic lines expressing hrap and pflp can provide a timely solution to the pandemic. However, the impact of the transgenes expression on non-target microorganisms has not yet been investigated. To study this effect, transgenic and control lines were grown under field conditions and their associated microbiome was investigated by 16S rRNA gene profiling combining amplicon sequencing and molecular fingerprinting. Three years after sucker planting, no statistically significant differences between transgenic lines and their non-modified predecessors were detected for their associated bacterial communities. The overall gammaproteobacterial rhizosphere microbiome was highly dominated by Xanthomonadales, while Pseudomonadales and Enterobacteriales were accumulated in the pseudostem. Shannon indices revealed much higher diversity in the rhizosphere than in the pseudostem endosphere. However, the expression of the transgenes did not result in changes in the diversity of Gammaproteobacteria, the closest relatives of the target pathogen. In this field experiment, the expression of the resistance genes appears to have no consequences for non-target rhizobacteria and endophytes.

  4. Ingestion of Bt rice pollen does not reduce the survival or hypopharyngeal gland development of Apis mellifera adults.

    Science.gov (United States)

    Wang, Yuanyuan; Dai, Pingli; Chen, Xiuping; Romeis, Jörg; Shi, Jianrong; Peng, Yufa; Li, Yunhe

    2017-05-01

    Because of its ecological and economic importance, the honey bee Apis mellifera is commonly used to assess the environmental risk of insect-resistant, genetically modified plants. In the present study, feeding-exposure experiments were used to determine whether pollen from transgenic rice harms A. mellifera worker bees. In 1 experiment, the survival and mean acinus diameter of hypopharyngeal glands of adult bees were similar when bees were fed on pollen from Bt rice lines or from a non-Bt rice line, but bee survival was significantly reduced when they received pollen that was mixed with potassium arsenate as a positive control. In a second experiment, bee survival and hypopharyngeal gland development were not reduced when adult bees were fed on non-Bt pollen and a sucrose solution supplemented with Cry2A at 400 µg/g, Cry1C at 50 µg/g, or bovine serum albumin (BSA) at 400 µg/g, but bee survival and hypopharyngeal gland development were reduced when the diet was supplemented with soybean trypsin inhibitor as a positive control. In both experiments, the uptake of Cry proteins by adult bees was confirmed. Overall, the results indicate that the planting of Bt rice lines expressing Cry2A or Cry1C protein poses a negligible risk to A. mellifera worker bees. Environ Toxicol Chem 2017;36:1243-1248. © 2016 SETAC. © 2016 SETAC.

  5. Obtaining of transgenic papaya plants var. Maradol roja that carry out the rice oryzacystatin gene

    Directory of Open Access Journals (Sweden)

    Milady F. Mendoza

    2004-10-01

    Full Text Available Papaya (Carica papaya L., is severely affected by Papaya Ringspot virus, which belongs to plant potyvirus group. A recent strategy for pest control produced by this virus is the transformation with genes encoding cysteine proteinase inhibitors. Rice oryzacistatin gene encoding for cystatins, was inserted in a pCAMBIA binary vector, for genetic transformation of papaya somatic embryos var. Maradol roja, mediated by gene gun. Gene integration was confirmed by means of polimerase chain reaction using the primers designed from gene bar sequence. Forty out of eighty in vitro transgenic papaya lines amplified a 402 fragment which correspond to the expecting size. Key words: Carica papaya, genetic engineering, potyvirus, proteinase inhibitor

  6. New downstream processing strategy for the purification of monoclonal antibodies from transgenic tobacco plants.

    Science.gov (United States)

    Platis, D; Drossard, J; Fischer, R; Ma, J K-C; Labrou, N E

    2008-11-21

    Affinity chromatography on immobilized Protein A is the current method of choice for the purification of monoclonal antibodies (mAbs). Despite its widespread use it presents certain drawbacks, such as ligand instability, leaching, toxicity and high cost. In the present work, we report a new procedure for the purification of two human monoclonal anti-HIV (human immunodeficiency virus) antibodies (mAbs 2G12 and 4E10) from transgenic tobacco plants using stable and low cost chromatographic materials. The first step of the mAb 2G12 purification procedure is comprised of an aqueous two-phase partition system (ATPS) for the removal of polyphenols while providing an essential initial purification boost (2.01-fold purification). In the second step, mAb 2G12 was purified using cation-exchange chromatography (CEX) on S-Sepharose FF, by elution with 20mM sodium phosphate buffer pH 7.5, containing 0.1M NaCl. The eluted mAb was directly loaded onto an immobilized metal affinity chromatography column (IMAC, Zn(2+)-iminodiacetic acid-Sepharose 6B) and eluted by stepwise pH gradient. The proposed method offered 162-fold purification with 97.2% purity and 63% yield. Analysis of the antibody preparation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), enzyme immunosorbent assay (ELISA) and western blot showed that the mAb 2G12 was fully active and free of degraded variants, polyphenols and alkaloids. The effectiveness of the present purification protocol was evaluated by using a second transgenic human monoclonal anti-HIV mAb 4E10. The results showed that the same procedure can be successfully used for the purification of mAb 4E10. In the case of mAb 4E10, the proposed method offered 148-fold purification with 96.2% purity and 36% yield. Therefore, the proposed protocol may be of generic use for the purification of mAbs from transgenic tobacco plants.

  7. Fidelity of a simple Liberty leaf-painting assay to validate transgenic maize plants expressing the selectable marker gene, bar

    Science.gov (United States)

    Screening of gene manipulation events (transgenic, mutation/genome editing etc.) is a cost/labor intensive and time-consuming process in plant science research. While PCR is the most definitive way for screening desired events, the process still requires efficient DNA extraction and subsequent steps...

  8. Transgenic Cotton Plants Expressing the HaHR3 Gene Conferred Enhanced Resistance to Helicoverpa armigera and Improved Cotton Yield.

    Science.gov (United States)

    Han, Qiang; Wang, Zhenzhen; He, Yunxin; Xiong, Yehui; Lv, Shun; Li, Shupeng; Zhang, Zhigang; Qiu, Dewen; Zeng, Hongmei

    2017-08-30

    RNA interference (RNAi) has been developed as an efficient technology. RNAi insect-resistant transgenic plants expressing double-stranded RNA (dsRNA) that is ingested into insects to silence target genes can affect the viability of these pests or even lead to their death. HaHR3 , a molt-regulating transcription factor gene, was previously selected as a target expressed in bacteria and tobacco plants to control Helicoverpa armigera by RNAi technology. In this work, we selected the dsRNA- HaHR3 fragment to silence HaHR3 in cotton bollworm for plant mediated-RNAi research. A total of 19 transgenic cotton lines expressing HaHR3 were successfully cultivated, and seven generated lines were used to perform feeding bioassays. Transgenic cotton plants expressing ds HaHR3 were shown to induce high larval mortality and deformities of pupation and adult eclosion when used to feed the newly hatched larvae, and 3rd and 5th instar larvae of H. armigera . Moreover, HaHR3 transgenic cotton also demonstrated an improved cotton yield when compared with controls.

  9. Disease resistance conferred by the expression of a gene encoding a synthetic peptide in transgenic cotton (Gossypium hirsutum L.) plants.

    Science.gov (United States)

    Rajasekaran, Kanniah; Cary, Jeffrey W; Jaynes, Jesse M; Cleveland, Thomas E

    2005-11-01

    Fertile, transgenic cotton plants expressing the synthetic antimicrobial peptide, D4E1, were produced through Agrobacterium-mediated transformation. PCR products and Southern blots confirmed integration of the D4E1 gene, while RT-PCR of cotton RNA confirmed the presence of D4E1 transcripts. In vitro assays with crude leaf protein extracts from T0 and T1 plants confirmed that D4E1 was expressed at sufficient levels to inhibit the growth of Fusarium verticillioides and Verticillium dahliae compared to extracts from negative control plants transformed with pBI-d35S(Omega)-uidA-nos (CGUS). Although in vitro assays did not show control of pre-germinated spores of Aspergillus flavus, bioassays with cotton seeds in situ or in planta, inoculated with a GFP-expressing A. flavus, indicated that the transgenic cotton seeds inhibited extensive colonization and spread by the fungus in cotyledons and seed coats. In planta assays with the fungal pathogen, Thielaviopsis basicola, which causes black root rot in cotton, showed typical symptoms such as black discoloration and constriction on hypocotyls, reduced branching of roots in CGUS negative control T1 seedlings, while transgenic T1 seedlings showed a significant reduction in disease symptoms and increased seedling fresh weight, demonstrating tolerance to the fungal pathogen. Significant advantages of synthetic peptides in developing transgenic crop plants that are resistant to diseases and mycotoxin-causing fungal pathogens are highlighted in this report.

  10. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene

    National Research Council Canada - National Science Library

    Thakur, Nidhi; Upadhyay, Santosh Kumar; Verma, Praveen C; Chandrashekar, Krishnappa; Tuli, Rakesh; Singh, Pradhyumna K

    2014-01-01

    .... The v-ATPase subunit A (v-ATPaseA) coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation...

  11. Enhanced Whitefly Resistance in Transgenic Tobacco Plants Expressing Double Stranded RNA of v-ATPase A Gene: e87235

    National Research Council Canada - National Science Library

    Nidhi Thakur; Santosh Kumar Upadhyay; Praveen C Verma; Krishnappa Chandrashekar; Rakesh Tuli; Pradhyumna K Singh

    2014-01-01

    .... The v-ATPase subunit A (v-ATPaseA) coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation...

  12. Impact of Bt-cotton on soil microbiological and biochemical attributes

    Directory of Open Access Journals (Sweden)

    Sanaullah Yasin

    2016-10-01

    Full Text Available Transgenic Bt-cotton produces Bt-toxins (Cry proteins which may accumulate and persist in soil due to their binding ability on soil components. In the present study, the potential impacts of Bt- and non-Bt genotypes of cotton on soil microbial activity, substrate use efficiency, viable microbial population counts, and nutrient dynamics were studied. Two transgenic Bt-cotton genotypes (CIM-602 CIM-599 expressing cry1 Ac gene and two non-Bt cotton genotypes (CIM-573 and CIM-591 were used to evaluate their impact on biological and chemical properties of soil across the four locations in Punjab. Field trials were conducted at four locations (Central Cotton Research Institute-Multan, Naseer Pur, Kot Lal Shah, and Cotton Research Station-Bahawalpur of different agro-ecological zones of Punjab. Rhizosphere soil samples were collected by following standard procedure from these selected locations. Results reveled that Bt-cotton had no adverse effect on microbial population (viable counts and enzymatic activity of rhizosphere soil. Bacterial population was more in Bt-cotton rhizosphere than that of non-Bt cotton rhizosphere at all locations. Phosphatase, dehydrogenase, and oxidative metabolism of rhizosphere soil were more in Bt-cotton genotypes compared with non-Bt cotton genotypes. Cation exchange capacity, total nitrogen, extractable phosphorous, extractable potassium, active carbon, Fe and Zn contents were higher in rhizosphere of Bt-cotton genotypes compared with non-Bt cotton genotypes. It can be concluded from present study that the cultivation of Bt-cotton expressing cry1 Ac had apparently no negative effect on metabolic, microbiological activities, and nutrient dynamics of soils. Further work is needed to investigate the potential impacts of Bt-cotton on ecology of soil-dwelling insects and invertebrates before its recommendation for extensive cultivation.

  13. Recent advances in utilizing transcription factors to improve plant abiotic stress tolerance by transgenic technology

    Directory of Open Access Journals (Sweden)

    Hongyan eWang

    2016-02-01

    Full Text Available Agricultural production and quality are adversely affected by various abiotic stresses worldwide and this will be exacerbated by the deterioration of global climate. To feed a growing world population, it is very urgent to breed stress-tolerant crops with higher yields and improved qualities against multiple environmental stresses. Since conventional breeding approaches had marginal success due to the complexity of stress tolerance traits, the transgenic approach is now being popularly used to breed stress-tolerant crops. So identifying and characterizing the the critical genes involved in plant stress responses is an essential prerequisite for engineering stress-tolerant crops. Far beyond the manipulation of single functional gene, engineering certain regulatory genes has emerged as an effective strategy now for controlling the expression of many stress-responsive genes. Transcription factors (TFs are good candidates for genetic engineering to breed stress-tolerant crop because of their role as master regulators of many stress-responsive genes. Many TFs belonging to families AP2/EREBP, MYB, WRKY, NAC, bZIP have been found to be involved in various abiotic stresses and some TF genes have also been engineered to improve stress tolerance in model and crop plants. In this review, we take five large families of TFs as examples and review the recent progress of TFs involved in plant abiotic stress responses and their potential utilization to improve multiple stress tolerance of crops in the field conditions.

  14. Delivery of multiple transgenes to plant cells by an improved version of MultiRound Gateway technology.

    Science.gov (United States)

    Buntru, Matthias; Gärtner, Stefanie; Staib, Lena; Kreuzaler, Fritz; Schlaich, Nikolaus

    2013-02-01

    At present, only few methods for the effective assembly of multigene constructs have been described. Here we present an improved version of the MultiRound Gateway technology, which facilitates plant multigene transformation. The system consists of two attL-flanked entry vectors, which contain an attR cassette, and a transformation-competent artificial chromosome based destination vector. By alternate use of the two entry vectors, multiple transgenes can be delivered sequentially into the Gateway-compatible destination vector. Multigene constructs that carried up to seven transgenes corresponding to more than 26 kb were assembled by seven rounds of LR recombination. The constructs were successfully transformed into tobacco plants and were stably inherited for at least two generations. Thus, our system represents a powerful, highly efficient tool for multigene plant transformation and may facilitate genetic engineering of agronomic traits or the assembly of genetic pathways for the production of biofuels, industrial or pharmaceutical compounds in plants.

  15. Testing public Bt maize events for control of stem borers in the first ...

    African Journals Online (AJOL)

    Transgenic maize (Zea mays L), developed using modified genes from the bacterium Bacillus thuringiensis (Bt), controls stem borers without observable negative effects to humans, livestock or the environment, and is now sown on 134 million hectares globally. Bt maize could contribute to increasing maize production in ...

  16. Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome

    OpenAIRE

    Kristensen, Charlotte; Morant, Marc; Olsen, Carl Erik; Ekstrøm, Claus T; Galbraith, David W; Lindberg Møller, Birger; Bak, Søren

    2005-01-01

    Focused and nontargeted approaches were used to assess the impact associated with introduction of new high-flux pathways in Arabidopsis thaliana by genetic engineering. Transgenic A. thaliana plants expressing the entire biosynthetic pathway for the tyrosine-derived cyanogenic glucoside dhurrin as accomplished by insertion of CYP79A1, CYP71E1, and UGT85B1 from Sorghum bicolor were shown to accumulate 4% dry-weight dhurrin with marginal inadvertent effects on plant morphology, free amino acid ...

  17. Transgenic Arabidopsis plants expressing the type 1 inositol 5-phosphatase exhibit increased drought tolerance and altered abscisic acid signaling.

    Science.gov (United States)

    Perera, Imara Y; Hung, Chiu-Yueh; Moore, Candace D; Stevenson-Paulik, Jill; Boss, Wendy F

    2008-10-01

    The phosphoinositide pathway and inositol-1,4,5-trisphosphate (InsP(3)) are implicated in plant responses to stress. To determine the downstream consequences of altered InsP(3)-mediated signaling, we generated transgenic Arabidopsis thaliana plants expressing the mammalian type I inositol polyphosphate 5-phosphatase (InsP 5-ptase), which specifically hydrolyzes soluble inositol phosphates and terminates the signal. Rapid transient Ca(2+) responses to a cold or salt stimulus were reduced by approximately 30% in these transgenic plants. Drought stress studies revealed, surprisingly, that the InsP 5-ptase plants lost less water and exhibited increased drought tolerance. The onset of the drought stress was delayed in the transgenic plants, and abscisic acid (ABA) levels increased less than in the wild-type plants. Stomatal bioassays showed that transgenic guard cells were less responsive to the inhibition of opening by ABA but showed an increased sensitivity to ABA-induced closure. Transcript profiling revealed that the drought-inducible ABA-independent transcription factor DREB2A and a subset of DREB2A-regulated genes were basally upregulated in the InsP 5-ptase plants, suggesting that InsP(3) is a negative regulator of these DREB2A-regulated genes. These results indicate that the drought tolerance of the InsP 5-ptase plants is mediated in part via a DREB2A-dependent pathway and that constitutive dampening of the InsP(3) signal reveals unanticipated interconnections between signaling pathways.

  18. Cyanobacterial flavodoxin complements ferredoxin deficiency in knocked-down transgenic tobacco plants.

    Science.gov (United States)

    Blanco, Nicolás E; Ceccoli, Romina D; Segretin, María E; Poli, Hugo O; Voss, Ingo; Melzer, Michael; Bravo-Almonacid, Fernando F; Scheibe, Renate; Hajirezaei, Mohammad-Reza; Carrillo, Néstor

    2011-03-01

    Ferredoxins are the main electron shuttles in chloroplasts, accepting electrons from photosystem I and delivering them to essential oxido-reductive pathways in the stroma. Ferredoxin levels decrease under adverse environmental conditions in both plants and photosynthetic micro-organisms. In cyanobacteria and some algae, this decrease is compensated for by induction of flavodoxin, an isofunctional flavoprotein that can replace ferredoxin in many reactions. Flavodoxin is not present in plants, but tobacco lines expressing a plastid-targeted cyanobacterial flavodoxin developed increased tolerance to environmental stress. Chloroplast-located flavodoxin interacts productively with endogenous ferredoxin-dependent pathways, suggesting that its protective role results from replacement of stress-labile ferredoxin. We tested this hypothesis by using RNA antisense and interference techniques to decrease ferredoxin levels in transgenic tobacco. Ferredoxin-deficient lines showed growth arrest, leaf chlorosis and decreased CO(2) assimilation. Chlorophyll fluorescence measurements indicated impaired photochemistry, over-reduction of the photosynthetic electron transport chain and enhanced non-photochemical quenching. Expression of flavodoxin from the nuclear or plastid genome restored growth, pigment contents and photosynthetic capacity, and relieved the electron pressure on the electron transport chain. Tolerance to oxidative stress also recovered. In the absence of flavodoxin, ferredoxin could not be decreased below 45% of physiological content without fatally compromising plant survival, but in its presence, lines with only 12% remaining ferredoxin could grow autotrophically, with almost wild-type phenotypes. The results indicate that the stress tolerance conferred by flavodoxin expression in plants stems largely from functional complementation of endogenous ferredoxin by the cyanobacterial flavoprotein. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  19. Recombinant monoclonal antibody yield in transgenic tobacco plants is affected by the wounding response via an ethylene dependent mechanism.

    Science.gov (United States)

    Hassan, Sally; Colgan, Richard; Paul, Mathew J; Atkinson, Christopher J; Sexton, Amy L; van Dolleweerd, Craig J; Keshavarz-Moore, Eli; Ma, Julian K-C

    2012-12-01

    Variability in recombinant IgG yield in transgenic tobacco plants has previously been observed in relation to leaf position, and is interpreted as a function of ageing and the senescence process, leading to increasing protein degradation. Here, similar findings are demonstrated in plants of different ages, expressing IgG but not IgG-HDEL, an antibody form that accumulates within the endoplasmic reticulum. Antibody yields declined following wounding in young transgenic plants expressing IgG but not in those expressing IgG-HDEL. However, in mature IgG plants, the opposite was demonstrated, with significant boosts in yield, while mature IgG-HDEL plants could not be boosted. The lack of response in IgG-HDEL plants suggests that the changes induced by wounding occur post-translationally, and the findings might be explained by wounding responses that differ in plants according to their developmental stages. Plant mechanisms involved in senescence and wounding overlap to a significant degree and compounds such as ethylene, jasmonic acid and salicylic acid are important for mediating downstream effects. Treatment of transgenic plants with ethylene also resulted in a decrease in recombinant IgG yield, which was consistent with the finding that wounded plants could induce lower IgG yields in neighbouring non-wounded plants. Treatment with 1-MCP, an ethylene antagonist, abrogated the IgG yield drop that resulted from wounding, but had no effect on the more gradual IgG yield loss associated with increasing plant age.

  20. Assessment of heat shock protein 70 induction by heat in alfalfa varieties and constitutive overexpression in transgenic plants.

    Directory of Open Access Journals (Sweden)

    Nicoletta Ferradini

    Full Text Available Heat shock proteins (HSPs are molecular chaperones involved in many cellular functions. It has been shown that mammalian cytosolic HSP70 binds antigenic peptides mediating the activation of the immune system, and that it plays a determining role in tumour immunogenicity. This suggests that HSP70 may be used for the production of conjugated vaccines. Human and plant HSPs share high sequence similarity and some important biological functions in vitro. In addition, plant HSPs have no endotoxic side effects. Extraction of HSP70 from plants for use as vaccine adjuvant requires enhancing its concentration in plant tissues. In this work, we explored the possibility to produce HSP70 in both transgenic and non-transgenic plants, using alfalfa as a model species. First, a transcriptional analysis of a constitutive and an inducible HSP70 genes was conducted in Arabidopsis thaliana. Then the coding sequence of the inducible form was cloned and introduced into alfalfa by Agrobacterium-mediated transformation, and the accumulation of the protein in leaf tissue of transgenic plants was demonstrated. We also tested diverse alfalfa varieties for heat-inducible expression of endogenous HSP70, revealing variety-specific responses to heat shock.

  1. Analysis of T-DNA/Host-Plant DNA Junction Sequences in Single-Copy Transgenic Barley Lines

    Directory of Open Access Journals (Sweden)

    Joanne G. Bartlett

    2014-01-01

    Full Text Available Sequencing across the junction between an integrated transfer DNA (T-DNA and a host plant genome provides two important pieces of information. The junctions themselves provide information regarding the proportion of T-DNA which has integrated into the host plant genome, whilst the transgene flanking sequences can be used to study the local genetic environment of the integrated transgene. In addition, this information is important in the safety assessment of GM crops and essential for GM traceability. In this study, a detailed analysis was carried out on the right-border T-DNA junction sequences of single-copy independent transgenic barley lines. T-DNA truncations at the right-border were found to be relatively common and affected 33.3% of the lines. In addition, 14.3% of lines had rearranged construct sequence after the right border break-point. An in depth analysis of the host-plant flanking sequences revealed that a significant proportion of the T-DNAs integrated into or close to known repetitive elements. However, this integration into repetitive DNA did not have a negative effect on transgene expression.

  2. Evaluation of bioassays for testing Bt sweetpotato events against ...

    African Journals Online (AJOL)

    In addition, this method was the most labour intensive in terms of frequent replacement of root chips for weevil development. Hence, the most appropriate method for testing Bt efficacy in sweetpotato is the small root egg-plug bioassay. Nonetheless, none of the transgenic events tested provided weevil control probably ...

  3. Reproduction of root knot nematode (Meloidogyne incognita) on Bt ...

    African Journals Online (AJOL)

    SARAH

    2013-09-30

    Sep 30, 2013 ... incognita in Bt cotton (06Z604D), isoline (99M03) and HART 89M (local non-Bt cotton cultivar) under greenhouse conditions. Methods and results: Plant height, number of squares/bolls, fresh shoot and root weight were determined before root knot nematode (RKN) screening at 90 and 180 days after ...

  4. Transcriptome analysis reveals absence of unintended effects in drought-tolerant transgenic plants overexpressing the transcription factor ABF3.

    Science.gov (United States)

    Abdeen, Ashraf; Schnell, Jaimie; Miki, Brian

    2010-01-28

    Plants engineered for abiotic stress tolerance may soon be commercialized. The engineering of these plants typically involves the manipulation of complex multigene networks and may therefore have a greater potential to introduce pleiotropic effects than the simple monogenic traits that currently dominate the plant biotechnology market. While research on unintended effects in transgenic plant systems has been instrumental in demonstrating the substantial equivalence of many transgenic plant systems, it is essential that such analyses be extended to transgenic plants engineered for stress tolerance. Drought-tolerant Arabidopsis thaliana were engineered through overexpression of the transcription factor ABF3 in order to investigate unintended pleiotropic effects. In order to eliminate position effects, the Cre/lox recombination system was used to create control plant lines that contain identical T-DNA insertion sites but with the ABF3 transgene excised. This additionally allowed us to determine if Cre recombinase can cause unintended effects that impact the transcriptome. Microarray analysis of control plant lines that underwent Cre-mediated excision of the ABF3 transgene revealed only two genes that were differentially expressed in more than one plant line, suggesting that the impact of Cre recombinase on the transcriptome was minimal. In the absence of drought stress, overexpression of ABF3 had no effect on the transcriptome, but following drought stress, differences were observed in the gene expression patterns of plants overexpressing ABF3 relative to control plants. Examination of the functional distribution of the differentially expressed genes revealed strong similarity indicating that unintended pathways were not activated. The action of ABF3 is tightly controlled in Arabidopsis. In the absence of drought stress, ectopic activation of drought response pathways does not occur. In response to drought stress, overexpression of ABF3 results in a reprogramming of

  5. Functional analysis of a cotton cellulose synthase A4 gene promoter in transgenic tobacco plants.

    Science.gov (United States)

    Wu, Ai-Min; Hu, John S; Liu, Jin-Yuan

    2009-10-01

    A 1,482-bp promoter sequence of the cotton cellulose synthase gene (GhCesA4) was isolated from Chinese cultivar CRI12 of Gossypium hirsutum, and transcriptionally fused to a beta-glucuronidase (GUS) reporter gene for investigation of important regions controlling gene expression in transgenic tobacco plants. Histochemical staining showed that the full-length promoter directs efficient expression of the reporter gene in the roots, hypocotyls, vascular tissues of stems, trichomes, the central leaf veins, as well as in the anthers and pollen. Quantitative measurements of GUS activity demonstrated that higher expression levels were detected in the stems, fully expanded leaves, and styles of flowers. A series of 5' progressive deletions of the promoter revealed the presence of a negative regulatory region (-767 to -424) for promoter activity and a 247-bp fragment (-247 to -1) with the vascular tissue specificity of the basic transcription activity in the GhCesA4 promoter. Exposure of the transgenic tobacco to various abiotic stresses showed that the full-length construct predominantly responded to NAA, kinetin, and sugar. Furthermore, the NAA-response region was found to be located in the -1,482/-1204 fragment, while the element(s) for the sucrose-responsive expression may be present in the -247/-1 region in the GhCesA4 promoter. These findings will not only contribute to an explanation of the molecular mechanisms by which GhCesA4 participates in secondary cell wall morphogenesis and stress responses, but will also provide a good candidate for expression or accumulation of foreign genes of interest whose products are preferentially required in vascular tissues and are inducible under auxin treatment.

  6. Effects of overexpression of AaWRKY1 on artemisinin biosynthesis in transgenic Artemisia annua plants.

    Science.gov (United States)

    Han, Junli; Wang, Hongzhen; Lundgren, Anneli; Brodelius, Peter E

    2014-06-01

    The effective anti-malarial medicine artemisinin is costly because of the low content in Artemisia annua. Genetic engineering of A. annua is one of the most promising approaches to improve the yield of artemisinin. In this work, the transcription factor AaWRKY1, which is thought to be involved in the regulation of artemisinin biosynthesis, was cloned from A. annua var. Chongqing and overexpressed using the CaMV35S promoter or the trichome-specific CYP71AV1 promoter in stably transformed A. annua plants. The transcript level of AaWRKY1 was increased more than one hundred times under the CaMV35S promoter and about 40 times under the CYP71AV1 promoter. The overexpressed AaWRKY1 activated the transcription of CYP71AV1 and moreover the trichome-specific overexpression of AaWRKY1 improved the transcription of CYP71AV1 much more effectively than the constitutive overexpression of AaWRKY1, i.e. up to 33 times as compared to the wild-type plant. However the transcription levels of FDS, ADS, and DBR2 did not change significantly in transgenic plants. The significantly up-regulated CYP71AV1 promoted artemisinin biosynthesis, i.e. up to about 1.8 times as compared to the wild-type plant. It is demonstrated that trichome-specific overexpression of AaWRKY1 can significantly activate the transcription of CYP71AV1 and the up-regulated CYP71AV1 promotes artemisinin biosynthesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. A moso bamboo WRKY gene PeWRKY83 confers salinity tolerance in transgenic Arabidopsis plants.

    Science.gov (United States)

    Wu, Min; Liu, Huanlong; Han, Guomin; Cai, Ronghao; Pan, Feng; Xiang, Yan

    2017-09-15

    The WRKY family are transcription factors, involved in plant development, and response to biotic and abiotic stresses. Moso bamboo is an important bamboo that has high ecological, economic and cultural value and is widely distributed in the south of China. In this study, we performed a genome-wide identification of WRKY members in moso bamboo and identified 89 members. By comparative analysis in six grass genomes, we found the WRKY gene family may have experienced or be experiencing purifying selection. Based on relative expression levels among WRKY IIc members under three abiotic stresses, PeWRKY83 functioned as a transcription factor and was selected for detailed analysis. The transgenic Arabidopsis of PeWRKY83 showed superior physiological properties compared with the WT under salt stress. Overexpression plants were less sensitive to ABA at both germination and postgermination stages and accumulated more endogenous ABA under salt stress conditions. Further studies demonstrated that overexpression of PeWRKY83 could regulate the expression of some ABA biosynthesis genes (AtAAO3, AtNCED2, AtNCED3), signaling genes (AtABI1, AtPP2CA) and responsive genes (AtRD29A, AtRD29B, AtABF1) under salt stress. Together, these results suggested that PeWRKY83 functions as a novel WRKY-related TF which plays a positive role in salt tolerance by regulating stress-induced ABA synthesis.

  8. Transgenic Rice Plants Harboring Genomic DNA from Zizania latifolia Confer Bacterial Blight Resistance

    Directory of Open Access Journals (Sweden)

    Wei-wei SHEN

    2011-03-01

    Full Text Available Based on the sequence of a resistance gene analog FZ14 derived from Zizania latifolia (Griseb., a pair of specific PCR primers FZ14P1/FZ14P2 was designed to isolate candidate disease resistance gene. The pooled-PCR approach was adopted using the primer pair to screen a genomic transformation-competent artificial chromosome (TAC library derived from Z. latifolia. A positive TAC clone (ZR1 was obtained and confirmed by sequence analysis. The results indicated that ZR1 consisted of conserved motifs similar to P-loop (kinase 1a, kinase 2, kinase 3a and GLPL (Gly-Leu-Pro-Leu, suggesting that it could be a portion of NBS-LRR type of resistance gene. Using Agrobacterium-mediated transformation of Nipponbare mature embryo, a total of 48 independent transgenic T0 plants were obtained. Among them, 36 plants were highly resistant to the virulent bacterial blight strain PXO71. The results indicate that ZR1 contains at least one functional bacterial blight resistance gene.

  9. Spermine facilitates recovery from drought but does not confer drought tolerance in transgenic rice plants expressing Datura stramonium S-adenosylmethionine decarboxylase.

    Science.gov (United States)

    Peremarti, Ariadna; Bassie, Ludovic; Christou, Paul; Capell, Teresa

    2009-06-01

    Polyamines are known to play important roles in plant stress tolerance but it has been difficult to determine precise functions for each type of polyamine and their interrelationships. To dissect the roles of putrescine from the higher polyamines spermidine and spermine, we generated transgenic rice plants constitutively expressing a heterologous S-adenosylmethionine decarboxylase (SAMDC) gene from Datura stramonium so that spermidine and spermine levels could be investigated while maintaining a constant putrescine pool. Whereas transgenic plants expressing arginine decarboxylase (ADC) produced higher levels of putrescine, spermidine and spermine, and were protected from drought stress, transgenic plants expressing SAMDC produced normal levels of putrescine and showed drought symptoms typical of wild type plants under stress, but the transgenic plants showed a much more robust recovery on return to normal conditions (90% full recovery compared to 25% partial recovery for wild type plants). At the molecular level, both wild type and transgenic plants showed transient reductions in the levels of endogenous ADC1 and SAMDC mRNA, but only wild type plants showed a spike in putrescine levels under stress. In transgenic plants, there was no spike in putrescine but a smooth increase in spermine levels at the expense of spermidine. These results confirm and extend the threshold model for polyamine activity in drought stress, and attribute individual roles to putrescine, spermidine and spermine.

  10. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton

    Science.gov (United States)

    Gore, J.; Catchot, A.; Cook, D.; Musser, F.; Caprio, M.

    2016-01-01

    Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae. PMID:26809264

  11. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton.

    Science.gov (United States)

    Von Kanel, M B; Gore, J; Catchot, A; Cook, D; Musser, F; Caprio, M

    2016-04-01

    Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae.

  12. Farm-scale evaluation of the impacts of transgenic cotton on biodiversity, pesticide use, and yield

    OpenAIRE

    Cattaneo, Manda G.; Yafuso, Christine; Schmidt, Chris; Huang, Cho-ying; Rahman, Magfurar; Olson, Carl; Ellers-Kirk, Christa; Orr,Barron J.; Marsh, Stuart E.; Antilla, Larry; Dutilleul, Pierre; Carrière, Yves

    2006-01-01

    Higher yields and reduced pesticide impacts are needed to mitigate the effects of agricultural intensification. A 2-year farm-scale evaluation of 81 commercial fields in Arizona show that use of transgenic Bacillus thuringiensis (Bt) cotton reduced insecticide use, whereas transgenic cotton with Bt protein and herbicide resistance (BtHr) did not affect herbicide use. Transgenic cotton had higher yield than nontransgenic cotton for any given number of insecticide applications. However, nontran...

  13. The maize WRKY transcription factor ZmWRKY17 negatively regulates salt stress tolerance in transgenic Arabidopsis plants.

    Science.gov (United States)

    Cai, Ronghao; Dai, Wei; Zhang, Congsheng; Wang, Yan; Wu, Min; Zhao, Yang; Ma, Qing; Xiang, Yan; Cheng, Beijiu

    2017-12-01

    We cloned and characterized the ZmWRKY17 gene from maize. Overexpression of ZmWRKY17 in Arabidopsis led to increased sensitivity to salt stress and decreased ABA sensitivity through regulating the expression of some ABA- and stress-responsive genes. The WRKY transcription factors have been reported to function as positive or negative regulators in many different biological processes including plant development, defense regulation and stress response. This study isolated a maize WRKY gene, ZmWRKY17, and characterized its role in tolerance to salt stress by generating transgenic Arabidopsis plants. Expression of the ZmWRKY17 was up-regulated by drought, salt and abscisic acid (ABA) treatments. ZmWRKY17 was localized in the nucleus with no transcriptional activation in yeast. Yeast one-hybrid assay showed that ZmWRKY17 can specifically bind to W-box, and it can activate W-box-dependent transcription in planta. Heterologous overexpression of ZmWRKY17 in Arabidopsis remarkably reduced plant tolerance to salt stress, as determined through physiological analyses of the cotyledons greening rate, root growth, relative electrical leakage and malondialdehyde content. Additionally, ZmWRKY17 transgenic plants showed decreased sensitivity to ABA during seed germination and early seedling growth. Transgenic plants accumulated higher content of ABA than wild-type (WT) plants under NaCl condition. Transcriptome and quantitative real-time PCR analyses revealed that some stress-related genes in transgenic seedlings showed lower expression level than that in the WT when treated with NaCl. Taken together, these results suggest that ZmWRKY17 may act as a negative regulator involved in the salt stress responses through ABA signalling.

  14. A toxin-binding alkaline phosphatase fragment synergizes Bt toxin Cry1Ac against susceptible and resistant Helicoverpa armigera.

    Directory of Open Access Journals (Sweden)

    Wenbo Chen

    Full Text Available Evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (Cry proteins from the bacterium Bacillus thuringiensis (Bt in sprays and transgenic plants. In this study, laboratory selection with Cry1Ac yielded five strains of cotton bollworm, Helicoverpa armigera, with resistance ratios at the median lethal concentration (LC50 of activated Cry1Ac ranging from 22 to 1700. Reduced activity and reduced transcription of an alkaline phosphatase protein that binds Cry1Ac was associated with resistance to Cry1Ac in the four most resistant strains. A Cry1Ac-binding fragment of alkaline phosphatase from H. armigera (HaALP1f was not toxic by itself, but it increased mortality caused by Cry1Ac in a susceptible strain and in all five resistant strains. Although synergism of Bt toxins against susceptible insects by toxin-binding fragments of cadherin and aminopeptidase N has been reported previously, the results here provide the first evidence of synergism of a Bt toxin by a toxin-binding fragment of alkaline phosphatase. The results here also provide the first evidence of synergism of a Bt toxin by any toxin-binding peptide against resistant insects.

  15. Efficacy of genetically modified Bt toxins alone and in combinations against pink bollworm resistant to Cry1Ac and Cry2Ab

    Science.gov (United States)

    Evolution of resistance in pests threatens the long-term success of transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt). Previous work showed that genetically modified Bt toxins Cry1AbMod and Cry1AcMod effectively countered resistance to native Bt toxins Cry1Ab and ...

  16. Antisense repression of vacuolar and cell wall invertase in transgenic carrot alters early plant development and sucrose partitioning.

    Science.gov (United States)

    Tang, G Q; Lüscher, M; Sturm, A

    1999-02-01

    To unravel the functions of cell wall and vacuolar invertases in carrot, we used an antisense technique to generate transgenic carrot plants with reduced enzyme activity. Phenotypic alterations appeared at very early stages of development; indeed, the morphology of cotyledon-stage embryos was markedly changed. At the stage at which control plantlets had two to three leaves and one primary root, shoots of transgenic plantlets did not separate into individual leaves but consisted of stunted, interconnected green structures. When transgenic plantlets were grown on media containing a mixture of sucrose, glucose, and fructose rather than sucrose alone, the malformation was alleviated, and plantlets looked normal. Plantlets from hexose-containing media produced mature plants when transferred to soil. Plants expressing antisense mRNA for cell wall invertase had a bushy appearance due to the development of extra leaves, which accumulated elevated levels of sucrose and starch. Simultaneously, tap root development was markedly reduced, and the resulting smaller organs contained lower levels of carbohydrates. Compared with control plants, the dry weight leaf-to-root ratio of cell wall invertase antisense plants was shifted from 1:3 to 17:1. Plants expressing antisense mRNA for vacuolar invertase also had more leaves than did control plants, but tap roots developed normally, although they were smaller, and the leaf-to-root ratio was 1.5:1. Again, the carbohydrate content of leaves was elevated, and that of roots was reduced. Our data suggest that acid invertases play an important role in early plant development, most likely via control of sugar composition and metabolic fluxes. Later in plant development, both isoenzymes seem to have important functions in sucrose partitioning.

  17. Altered seed oil and glucosinolate levels in transgenic plants overexpressing the Brassica napus SHOOTMERISTEMLESS gene.

    Science.gov (United States)

    Elhiti, Mohamed; Yang, Cunchun; Chan, Ainsley; Durnin, Douglas C; Belmonte, Mark F; Ayele, Belay T; Tahir, Muhammad; Stasolla, Claudio

    2012-07-01

    SHOOTMERISTEMLESS (STM) is a homeobox gene conserved among plant species which is required for the formation and maintenance of the shoot meristem by suppressing differentiation and maintaining an undetermined cell fate within the apical pole. To assess further the role of this gene during seed storage accumulation, transgenic Brassica napus (Bn) plants overexpressing or down-regulating BnSTM under the control of the 35S promoter were generated. Overexpression of BnSTM increased seed oil content without affecting the protein and sucrose level. These changes were accompanied by the induction of genes encoding several transcription factors promoting fatty acid (FA) synthesis: LEAFY COTYLEDON1 (BnLEC1), BnLEC2, and WRINKLE1 (BnWRI1). In addition, expression of key representative enzymes involved in sucrose metabolism, glycolysis, and FA biosynthesis was up-regulated in developing seeds ectopically expressing BnSTM. These distinctive expression patterns support the view of an increased carbon flux to the FA biosynthetic pathway in developing transformed seeds. The overexpression of BnSTM also resulted in a desirable reduction of seed glucosinolate (GLS) levels ascribed to a transcriptional repression of key enzymes participating in the GLS biosynthetic pathway, and possibly to the differential utilization of common precursors for GLS and indole-3-acetic acid synthesis. No changes in oil and GLS levels were observed in lines down-regulating BnSTM. Taken together, these findings provide evidence for a novel function for BnSTM in promoting desirable changes in seed oil and GLS levels when overexpressed in B. napus plants, and demonstrate that this gene can be used as a target for genetic improvement of oilseed species.

  18. A Novel Stress-Induced Sugarcane Gene Confers Tolerance to Drought, Salt and Oxidative Stress in Transgenic Tobacco Plants

    Science.gov (United States)

    Begcy, Kevin; Mariano, Eduardo D.; Gentile, Agustina; Lembke, Carolina G.; Zingaretti, Sonia Marli; Souza, Glaucia M.; Menossi, Marcelo

    2012-01-01

    Background Drought is a major abiotic stress that affects crop productivity worldwide. Sugarcane can withstand periods of water scarcity during the final stage of culm maturation, during which sucrose accumulation occurs. Meanwhile, prolonged periods of drought can cause severe plant losses. Methodology/Principal Findings In a previous study, we evaluated the transcriptome of drought-stressed plants to better understand sugarcane responses to drought. Among the up-regulated genes was Scdr1 (sugarcane drought-responsive 1). The aim of the research reported here was to characterize this gene. Scdr1 encodes a putative protein containing 248 amino acids with a large number of proline (19%) and cysteine (13%) residues. Phylogenetic analysis showed that ScDR1is in a clade with homologs from other monocotyledonous plants, separate from those of dicotyledonous plants. The expression of Scdr1 in different varieties of sugarcane plants has not shown a clear association with drought tolerance. Conclusions/Significance The overexpression of Scdr1 in transgenic tobacco plants increased their tolerance to drought, salinity and oxidative stress, as demonstrated by increased photosynthesis, water content, biomass, germination rate, chlorophyll content and reduced accumulation of ROS. Physiological parameters, such as transpiration rate (E), net photosynthesis (A), stomatal conductance (gs) and internal leaf CO2 concentration, were less affected by abiotic stresses in transgenic Scdr1 plants compared with wild-type plants. Overall, our results indicated that Scdr1 conferred tolerance to multiple abiotic stresses, highlighting the potential of this gene for biotechnological applications. PMID:22984543

  19. Changes in SBPase activity influence photosynthetic capacity, growth, and tolerance to chilling stress in transgenic tomato plants

    Science.gov (United States)

    Ding, Fei; Wang, Meiling; Zhang, Shuoxin; Ai, Xizhen

    2016-01-01

    Sedoheptulose-1, 7-bisphosphatase (SBPase) is an important enzyme involved in photosynthetic carbon fixation in the Calvin cycle. Here, we report the impact of changes in SBPase activity on photosynthesis, growth and development, and chilling tolerance in SBPase antisense and sense transgenic tomato (Solanum lycopersicum) plants. In transgenic plants with increased SBPase activity, photosynthetic rates were increased and in parallel an increase in sucrose and starch accumulation was evident. Total biomass and leaf area were increased in SBPase sense plants, while they were reduced in SBPase antisense plants compared with equivalent wild-type tomato plants. Under chilling stress, when compared with plants with decreased SBPase activity, tomato plants with increased SBPase activity were found to be more chilling tolerant as indicated by reduced electrolyte leakage, increased photosynthetic capacity, and elevated RuBP regeneration rate and quantum efficiency of photosystem II. Collectively, our data suggest that higher level of SBPase activity gives an advantage to photosynthesis, growth and chilling tolerance in tomato plants. This work also provides a case study that an individual enzyme in the Calvin cycle may serve as a useful target for genetic engineering to improve production and stress tolerance in crops. PMID:27586456

  20. Transgenic plants and animals: Altered organisms from recombinant DNA technology. (Latest citations from the Life Sciences Collection data base). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    1992-06-01

    The bibliography contains citations concerning the development and use of transgenic plants and animals. Transgenic plants and animals are organisms with foreign genes inserted into their cells. Topics include methods of induction of new genes and transgenetic expression in the organism, development of animal models of human diseases, and design of insect tolerant plants. Examples of transgenic organisms include mice, fish, chickens, pigs, rye, maize, tobacco, tomatoes, lettuce, and cotton. This information is of value for the increased production of food from animals by producing animal carcasses with reduced fat content. The information is also valuable for production of herbicide tolerant, virus resistant, and insect resistant crop plants, as well as the rapid production of transgenic plants with flowers and seeds. (Contains 250 citations and includes a subject term index and title list.)

  1. Bitrophic and Tritrophic Effects of Transgenic cry1Ab/cry2Aj Maize on the Beneficial, Nontarget Harmonia axyridis (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Chang, Xue; Lu, Zengbin; Shen, Zhicheng; Peng, Yufa; Ye, Gongyin

    2017-10-01

    Harmonia axyridis (Pallas) is a common and abundant predator in China and may be exposed to Cry toxins that are produced in Bt crops either by feeding on plant parts or by feeding on target or nontarget herbivorous insects. A new Bt maize line, expressing the Cry1Ab/Cry2Aj fused protein, has been developed and should be rigorously assessed for the ecological risks on the natural enemy. Laboratory experiments were carried out to study the effects of this Bt maize on nontarget predator H. axyridis via bitrophic interaction of adult H. axyridis feeding on Bt maize pollen and tritrophic interaction of H. axyridis consuming the lepidopteran prey. Spodoptera exigua (Hübner) neonate larvae were used to transfer Bt protein because they could survive after ingesting transgenic cry1Ab/cry2Aj maize kernels in the previous study. ELISA bioassays confirmed that the Bt protein could be transferred, but diluted through Bt maize-prey-predator. Life history parameters such as survival, development, weight, fecundity, and egg hatching rate were not significantly different when H. axyridis consumed prey that had been reared on Bt maize compared with prey reared on a nontransformed parental control. Furthermore, feeding directly on Bt maize pollen also had no detrimental effects on fitness, survival, and weight of female and male adults. In conclusion, our results indicate that transgenic cry1Ab/cry2Aj maize poses no ecological risks on the nontarget predator H. axyridis. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Petunia floral defensins with unique prodomains as novel candidates for development of fusarium wilt resistance in transgenic banana plants.

    Science.gov (United States)

    Ghag, Siddhesh B; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2012-01-01

    Antimicrobial peptides are a potent group of defense active molecules that have been utilized in developing resistance against a multitude of plant pathogens. Floral defensins constitute a group of cysteine-rich peptides showing potent growth inhibition of pathogenic filamentous fungi especially Fusarium oxysporum in vitro. Full length genes coding for two Petunia floral defensins, PhDef1 and PhDef2 having unique C-terminal 31 and 27 amino acid long predicted prodomains, were overexpressed in transgenic banana plants using embryogenic cells as explants for Agrobacterium-mediated genetic transformation. High level constitutive expression of these defensins in elite banana cv. Rasthali led to significant resistance against infection of Fusarium oxysporum f. sp. cubense as shown by in vitro and ex vivo bioassay studies. Transgenic banana lines expressing either of the two defensins were clearly less chlorotic and had significantly less infestation and discoloration in the vital corm region of the plant as compared to untransformed controls. Transgenic banana plants expressing high level of full-length PhDef1 and PhDef2 were phenotypically normal and no stunting was observed. In conclusion, our results suggest that high-level constitutive expression of floral defensins having distinctive prodomains is an efficient strategy for development of fungal resistance in economically important fruit crops like banana.

  3. Petunia floral defensins with unique prodomains as novel candidates for development of fusarium wilt resistance in transgenic banana plants.

    Directory of Open Access Journals (Sweden)

    Siddhesh B Ghag

    Full Text Available Antimicrobial peptides are a potent group of defense active molecules that have been utilized in developing resistance against a multitude of plant pathogens. Floral defensins constitute a group of cysteine-rich peptides showing potent growth inhibition of pathogenic filamentous fungi especially Fusarium oxysporum in vitro. Full length genes coding for two Petunia floral defensins, PhDef1 and PhDef2 having unique C-terminal 31 and 27 amino acid long predicted prodomains, were overexpressed in transgenic banana plants using embryogenic cells as explants for Agrobacterium-mediated genetic transformation. High level constitutive expression of these defensins in elite banana cv. Rasthali led to significant resistance against infection of Fusarium oxysporum f. sp. cubense as shown by in vitro and ex vivo bioassay studies. Transgenic banana lines expressing either of the two defensins were clearly less chlorotic and had significantly less infestation and discoloration in the vital corm region of the plant as compared to untransformed controls. Transgenic banana plants expressing high level of full-length PhDef1 and PhDef2 were phenotypically normal and no stunting was observed. In conclusion, our results suggest that high-level constitutive expression of floral defensins having distinctive prodomains is an efficient strategy for development of fungal resistance in economically important fruit crops like banana.

  4. Functional analysis of six drought-inducible promoters in transgenic rice plants throughout all stages of plant growth.

    Science.gov (United States)

    Yi, Nari; Kim, Youn Shic; Jeong, Min-Ho; Oh, Se-Jun; Jeong, Jin Seo; Park, Su-Hyun; Jung, Harin; Choi, Yang Do; Kim, Ju-Kon

    2010-08-01

    There are few efficient promoters for use with stress-inducible gene expression in plants, and in particular for monocotyledonous crops. Here, we report the identification of six genes, Rab21, Wsi18, Lea3, Uge1, Dip1, and R1G1B that were induced by drought stress in rice microarray experiments. Gene promoters were linked to the gfp reporter and their activities were analyzed in transgenic rice plants throughout all stages of plant growth, from dry seeds to vegetative tissues to flowers, both before and after drought treatments. In fold induction levels, Rab21 and Wsi18 promoters ranged from 65- and 36-fold in leaves to 1,355- and 492-fold in flowers, respectively, whereas Lea3 and Uge1 were higher in leaves, but lower in roots and flowers, as compared with Rab21 and Wsi18. Dip1 and R1G1B promoters had higher basal levels of activity under normal growth conditions in all tissues, resulting in smaller fold-induction levels than those of the others. In drought treatment time course, activities of Dip1 and R1G1B promoters rapidly increased, peaked at 2 h, and remained constant until 8 h, while that of Lea3 slowly yet steadily increased until 8 h. Interestingly, Rab21 activity increased rapidly and steadily in response to drought stress until expression peaked at 8 h. Thus, we have isolated and characterized six rice promoters that are all distinct in fold induction, tissue specificity, and induction kinetics under drought conditions, providing a variety of drought-inducible promoters for crop biotechnology.

  5. Interactions between Bt crops and aquatic ecosystems: A review.

    Science.gov (United States)

    Venter, Hermoine J; Bøhn, Thomas

    2016-12-01

    The term Bt crops collectively refers to crops that have been genetically modified to include a gene (or genes) sourced from Bacillus thuringiensis (Bt) bacteria. These genes confer the ability to produce proteins toxic to certain insect pests. The interaction between Bt crops and adjacent aquatic ecosystems has received limited attention in research and risk assessment, despite the fact that some Bt crops have been in commercial use for 20 yr. Reports of effects on aquatic organisms such as Daphnia magna, Elliptio complanata, and Chironomus dilutus suggest that some aquatic species may be negatively affected, whereas other reports suggest that the decreased use of insecticides precipitated by Bt crops may benefit aquatic communities. The present study reviews the literature regarding entry routes and exposure pathways by which aquatic organisms may be exposed to Bt crop material, as well as feeding trials and field surveys that have investigated the effects of Bt-expressing plant material on such organisms. The present review also discusses how Bt crop development has moved past single-gene events, toward multigene stacked varieties that often contain herbicide resistance genes in addition to multiple Bt genes, and how their use (in conjunction with co-technology such as glyphosate/Roundup) may impact and interact with aquatic ecosystems. Lastly, suggestions for further research in this field are provided. Environ Toxicol Chem 2016;35:2891-2902. © 2016 SETAC. © 2016 SETAC.

  6. Expression of a methionine-rich storage albumin from the Brazil nut (Bertholletia excelsa H.B.K., Lecythidaceae in transgenic bean plants (Phaseolus vulgaris L., Fabaceae

    Directory of Open Access Journals (Sweden)

    Aragão F.J.L.

    1999-01-01

    Full Text Available Bean (Phaseolus vulgaris, an important component in the diet of people in developing countries, has low levels of the essential amino acid, methionine. We have attempted to correct this deficiency by introducing a transgene coding for a methionine-rich storage albumin from the Brazil nut via biolistic methods. The transgene's coding sequence was driven by a doubled 35S CaMV promoter and AMV enhancer sequences. The transgene was stable and correctly expressed in homozygous R2 to R5 seeds. In two of the five transgenic lines the methionine content was significantly increased (14 and 23% over the values found in untransformed plants.

  7. Constitutive over-expression of rice chymotrypsin protease inhibitor gene OCPI2 results in enhanced growth, salinity and osmotic stress tolerance of the transgenic Arabidopsis plants.

    Science.gov (United States)

    Tiwari, Lalit Dev; Mittal, Dheeraj; Chandra Mishra, Ratnesh; Grover, Anil

    2015-07-01

    Protease inhibitors are involved primarily in defense against pathogens. In recent years, these proteins have also been widely implicated in response of plants to diverse abiotic stresses. Rice chymotrypsin protease inhibitor gene OCPI2 is highly induced under salt and osmotic stresses. The construct containing the complete coding sequence of OCPI2 cloned downstream to CaMV35S promoter was transformed in Arabidopsis and single copy, homozygous transgenic lines were produced. The transgenic plants exhibited significantly enhanced tolerance to NaCl, PEG and mannitol stress as compared to wild type plants. Importantly, the vegetative and reproductive growth of transgenic plants under unstressed, control conditions was also enhanced: transgenic plants were more vigorous than wild type, resulting into higher yield in terms of silique number. The RWC values and membrane stability index of transgenic in comparison to wild type plants was higher. Higher proline content was observed in the AtOCPI2 lines, which was associated with higher transcript expression of pyrroline-5-carboxylate synthase and lowered levels of proline dehydrogenase genes. The chymotrypsin protease activities were lower in the transgenic as against wild type plants, under both unstressed, control as well as stressed conditions. It thus appears that rice chymotrypsin protease inhibitor gene OCPI2 is a useful candidate gene for genetic improvement of plants against salt and osmotic stress. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. Evaluation of the resistance of transgenic potato plants expressing various levels of Cry3A against the Colorado potato beetle (Leptinotarsa decemlineata Say) in the laboratory and field.

    Science.gov (United States)

    Zhou, Zhaoxu; Pang, Jinhuan; Guo, Wenchao; Zhong, Naiqin; Tian, Yingchuan; Xia, Guixian; Wu, Jiahe

    2012-12-01

    The Colorado potato beetle (CPB), Leptinotarsa decemlineata Say, is a destructive pest. The CPB is a quarantine pest in China, but has now invaded the Xinjiang Uygur Autonomous Region and is continuing to spread eastwards. To control the damage and overspreading, transgenic potato plants expressing Cry3A toxin were developed, and their resistance to CPB was evaluated by bioassays in the laboratory and field in 2009, 2010 and 2011. The insect resistance of the high-dose (HD) transgenic lines was significantly greater than the middle-dose (MD) and low-dose (LD) transgenic lines regarding leaf consumption, biomass accumulation and mortality. The HD and MD transgenic lines showed 100% mortality when inoculated with first- and second-instar larvae; however, the LD transgenic lines showed about 50% mortality. The HD transgenic lines exhibited a significantly higher yield than the MD and LD transgenic lines owing to their high CPB resistance. Commercially available transgenic potato plants with above 0.1% Cry3A of total soluble protein and NT control refugia could control damage, delay adaptation and halt dispersion eastwards. The two HD transgenic lines developed in this study, PAH1 and PAH2, are ideal for use as cultivars or germplasm to breed new cultivars. Copyright © 2012 Society of Chemical Industry.

  9. Evaluating ascorbate oxidase as a plant defense against leaf-chewing insects using transgenic poplar.

    Science.gov (United States)

    Barbehenn, Raymond V; Jaros, Adam; Yip, Lynn; Tran, Lan; Kanellis, Angelos K; Constabel, C Peter

    2008-10-01

    Ascorbate is the major water-soluble antioxidant in plants and animals, and it is an essential nutrient for most insect herbivores. Therefore, ascorbate oxidase (AO) has been proposed to function as a plant defense that decreases the availability of ascorbate to insects. This hypothesis was tested by producing transgenic poplar (Populus tremula x Populus alba; Salicaceae) with 14- to 37-fold higher foliar AO activities than control (wild type) leaves and feeding these leaves to Lymantria dispar L. (Lepidoptera: Lymantriidae) caterpillars and Melanoplus sanguinipes (Fabricius) (Orthoptera: Acrididae) grasshoppers. To examine potential mechanisms of activity of AO in these insects, ascorbyl radical and/or ascorbate levels were measured in gut contents. No significant changes in ascorbyl radical or ascorbate levels were found in the midgut contents of L. dispar larvae that ingested the leaves of the AO-overexpressing genotypes compared to the control genotype, and no significant decreases in ascorbate levels were found in the foregut or midgut contents of M. sanguinipes. Treatment of control leaves with commercial AO also produced no changes in the midgut biochemistry of L. dispar larvae, as measured by levels of ascorbyl radicals. Likewise, no increase in oxidative stress was observed in L. dispar that consumed tannin-treated AO-overexpressing leaves compared with tannin-treated control genotype leaves. Performance experiments were carried out on first- and fourth-instar L. dispar larvae on leaf disks and on third instars feeding on intact leaves on trees. In no case was a significant difference found in the contrast between the control and three AO-overexpressing genotypes for relative consumption rate, relative growth rate, or nutritional indices. We conclude that elevated levels of AO in poplar are unlikely to serve as a defense against herbivores such as L. dispar or M. sanguinipes and that the low oxygen levels commonly found in the guts of caterpillars and

  10. Chrysanthemum WRKY gene CmWRKY17 negatively regulates salt stress tolerance in transgenic chrysanthemum and Arabidopsis plants.

    Science.gov (United States)

    Li, Peiling; Song, Aiping; Gao, Chunyan; Wang, Linxiao; Wang, Yinjie; Sun, Jing; Jiang, Jiafu; Chen, Fadi; Chen, Sumei

    2015-08-01

    CmWRKY17 was induced by salinity in chrysanthemum, and it might negatively regulate salt stress in transgenic plants as a transcriptional repressor. WRKY transcription factors play roles as positive or negative regulators in response to various stresses in plants. In this study, CmWRKY17 was isolated from chrysanthemum (Chrysanthemum morifolium). The gene encodes a 227-amino acid protein and belongs to the group II WRKY family, but has an atypical WRKY domain with the sequence WKKYGEK. Our data indicated that CmWRKY17 was localized to the nucleus in onion epidermal cells. CmWRKY17 showed no transcriptional activation in yeast; furthermore, luminescence assay clearly suggested that CmWRKY17 functions as a transcriptional repressor. DNA-binding assay showed that CmWRKY17 can bind to W-box. The expression of CmWRKY17 was induced by salinity in chrysanthemum, and a higher expression level was observed in the stem and leaf compared with that in the root, disk florets, and ray florets. Overexpression of CmWRKY17 in chrysanthemum and Arabidopsis increased the sensitivity to salinity stress. The activities of superoxide dismutase and peroxidase and proline content in the leaf were significantly lower in transgenic chrysanthemum than those in the wild type under salinity stress, whereas electrical conductivity was increased in transgenic plants. Expression of the stress-related genes AtRD29, AtDREB2B, AtSOS1, AtSOS2, AtSOS3, and AtNHX1 was reduced in the CmWRKY17 transgenic Arabidopsis compared with that in the wild-type Col-0. Collectively, these data suggest that CmWRKY17 may increase the salinity sensitivity in plants as a transcriptional repressor.

  11. Silencing the HaAK Gene by Transgenic Plant-Mediated RNAi Impairs Larval Growth of Helicoverpa armigera

    OpenAIRE

    Liu, Feng; Wang, Xiao-Dong; Zhao, Yi-Ying; Li, Yan-Jun; Liu, Yong-Chang; Sun, Jie

    2015-01-01

    Insect pests have caused noticeable economic losses in agriculture, and the heavy use of insecticide to control pests not only brings the threats of insecticide resistance but also causes the great pollution to foods and the environment. Transgenic plants producing double-stranded RNA (dsRNA) directed against insect genes have been is currently developed for protection against insect pests. In this study, we used this technology to silence the arginine kinase (AK) gene of Helicoverpa armigera...

  12. Evaluation of the photosynthetic activity in transgenic tobacco plants with altered endogenous cytokinin content: lessons from cytokinin

    OpenAIRE

    Cortleven, Anne; Valcke, Roland

    2012-01-01

    Cytokinin is known to be involved in many processes related to plastid development and function but the exact role of cytokinin in photosynthesis remains elusive. To investigate more profoundly the effects of cytokinin in this process, the photosynthetic activity of transgenic Pssu-ipt and 35S:CKX1 tobacco (Nicotiana tabacum) plants with respectively elevated and reduced endogenous cytokinin content was evaluated. Pigment analysis indicated that elevated endogenous cytokinin...

  13. Consumption of Bt maize pollen expressing Cry1Ab or Cry3Bb1 does not harm adult green Lacewings, Chrysoperla carnea (Neuroptera: Chrysopidae.

    Directory of Open Access Journals (Sweden)

    Yunhe Li

    Full Text Available Adults of the common green lacewing, Chrysoperla carnea (Stephens (Neuroptera: Chrysopidae, are prevalent pollen-consumers in maize fields. They are therefore exposed to insecticidal proteins expressed in the pollen of insect-resistant, genetically engineered maize varieties expressing Cry proteins derived from Bacillus thuringiensis (Bt. Laboratory experiments were conducted to evaluate the impact of Cry3Bb1 or Cry1Ab-expressing transgenic maize (MON 88017, Event Bt176 pollen on fitness parameters of adult C. carnea. Adults were fed pollen from Bt maize varieties or their corresponding near isolines together with sucrose solution for 28 days. Survival, pre-oviposition period, fecundity, fertility and dry weight were not different between Bt or non-Bt maize pollen treatments. In order to ensure that adults of C. carnea are not sensitive to the tested toxins independent from the plant background and to add certainty to the hazard assessment, adult C. carnea were fed with artificial diet containing purified Cry3Bb1 or Cry1Ab at about a 10 times higher concentration than in maize pollen. Artificial diet containing Galanthus nivalis agglutinin (GNA was included as a positive control. No differences were found in any life-table parameter between Cry protein containing diet treatments and control diet. However, the pre-oviposition period, daily and total fecundity and dry weight of C. carnea were significantly negatively affected by GNA-feeding. In both feeding assays, the stability and bioactivity of Cry proteins in the food sources as well as the uptake by C. carnea was confirmed. These results show that adults of C. carnea are not affected by Bt maize pollen and are not sensitive to Cry1Ab and Cry3Bb1 at concentrations exceeding the levels in pollen. Consequently, Bt maize pollen consumption will pose a negligible risk to adult C. carnea.

  14. Consumption of Bt maize pollen expressing Cry1Ab or Cry3Bb1 does not harm adult green Lacewings, Chrysoperla carnea (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Li, Yunhe; Meissle, Michael; Romeis, Jörg

    2008-08-06

    Adults of the common green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), are prevalent pollen-consumers in maize fields. They are therefore exposed to insecticidal proteins expressed in the pollen of insect-resistant, genetically engineered maize varieties expressing Cry proteins derived from Bacillus thuringiensis (Bt). Laboratory experiments were conducted to evaluate the impact of Cry3Bb1 or Cry1Ab-expressing transgenic maize (MON 88017, Event Bt176) pollen on fitness parameters of adult C. carnea. Adults were fed pollen from Bt maize varieties or their corresponding near isolines together with sucrose solution for 28 days. Survival, pre-oviposition period, fecundity, fertility and dry weight were not different between Bt or non-Bt maize pollen treatments. In order to ensure that adults of C. carnea are not sensitive to the tested toxins independent from the plant background and to add certainty to the hazard assessment, adult C. carnea were fed with artificial diet containing purified Cry3Bb1 or Cry1Ab at about a 10 times higher concentration than in maize pollen. Artificial diet containing Galanthus nivalis agglutinin (GNA) was included as a positive control. No differences were found in any life-table parameter between Cry protein containing diet treatments and control diet. However, the pre-oviposition period, daily and total fecundity and dry weight of C. carnea were significantly negatively affected by GNA-feeding. In both feeding assays, the stability and bioactivity of Cry proteins in the food sources as well as the uptake by C. carnea was confirmed. These results show that adults of C. carnea are not affected by Bt maize pollen and are not sensitive to Cry1Ab and Cry3Bb1 at concentrations exceeding the levels in pollen. Consequently, Bt maize pollen consumption will pose a negligible risk to adult C. carnea.

  15. Genetic transformation, recovery, and characterization of fertile soybean transgenic for a synthetic Bacillus thuringiensis cryIAc gene.

    Science.gov (United States)

    Stewart, C N; Adang, M J; All, J N; Boerma, H R; Cardineau, G; Tucker, D; Parrott, W A

    1996-01-01

    Somatic embryos of jack, a Glycine max (L.) Merrill cultivar, were transformed using microprojectile bombardment with a synthetic Bacillus thuringiensis insecticidal crystal protein gene (Bt cryIAc) driven by the 35S promoter and linked to the HPH gene. Approximately 10 g of tissue was bombarded, and three transgenic lines were selected on hygromycin-containing media and converted into plants. The recovered lines contained the HPH gene, but the Bt gene was lost in one line. The plasmid was rearranged in the second line, and the third line had two copies, one of which was rear-ranged. The CryIAc protein accumulated up to 46 ng mg-1 extractable protein. In detached-leaf bioassays, plants with an intact copy of the Bt gene, and to a lesser extent those with the rearranged copy, were protected from damage from corn earworm (Helicoverpa zea), soybean looper (Pseudoplusia includens), tobacco budworm (Heliothis virescens), and velvetbean caterpillar (Anticarsia gemmatalis). Corn earworm produced less than 3% defoliation on transgenic plants, compared with 20% on the lepidopteran-resistant breeding line GatIR81-296, and more than 40% on susceptible cultivars. Unlike previous reports of soybean transformation using this technique, all plants were fertile. To our knowledge, this is the first report of a soybean transgenic for a highly expressed insecticidal gene. PMID:8819322

  16. IMPACT OF BT ( BACILLUS THURINGIENSIS ) CROPS ON BAT ACTIVITY IN SOUTH TEXAS AGROECOSYSTEMS

    Science.gov (United States)

    The widespread adoption of transgenic insecticidal crops raises concerns that nontarget species may be harmed and food webs disrupted. The goal of this research is to determine how transgenic Bt (Bacillus thuringiensis) crops impact the activity of Brazilian freetailed bats (Tada...

  17. OBTAINING OF THE TRANSGENIC HELIANTHUS TUBEROSUS L. PLANTS, CALLUS AND "HAIRY" ROOT CULTURES ABLE TO EXPRESS THE RECOMBINANT HUMAN INTERFERON ALPHA-2b GENE.

    Science.gov (United States)

    Maistrenko, O M; Luchakivska, Yu S; Zholobak, N M; Spivak, M Ya; Kuchuk, M V

    2015-01-01

    This work is the first to our knowledge to describe the successful attempt of Agrobacterium rhizogenes-mediated transformation of topinambour in order to obtain the transgenic H. tuberosus plants, callus and "hairy" root cultures. The plasmid vectors contained the sequence of interferon gene fused with Nicotiana plumbagenifolia L. calreticulin apoplast targeting signal driven by 35S CaMV promoter or root-specific Mll promoter. Nearly 75% isolated Ri-root lines and callus cultures were proved (by PCR analysis) to contain HuINFa-2b transgene. We also managed to obtain H. tuberosus transgenic plants through somatic embryogenesis on the transgenic "hairy" root culture. The obtained transgenic H. tuberosus cultures exhibited high-level antiviral activity that ranged from 2000 to 54500 IU/g FW that makes this crop considered a promising source of recombinant interferon alpha 2b protein.

  18. Double overexpression of DREB and PIF transcription factors improves drought stress tolerance and cell elongation in transgenic plants.

    Science.gov (United States)

    Kudo, Madoka; Kidokoro, Satoshi; Yoshida, Takuya; Mizoi, Junya; Todaka, Daisuke; Fernie, Alisdair R; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2017-04-01

    Although a variety of transgenic plants that are tolerant to drought stress have been generated, many of these plants show growth retardation. To improve drought tolerance and plant growth, we applied a gene-stacking approach using two transcription factor genes: DEHYDRATION-RESPONSIVE ELEMENT-BINDING 1A (DREB1A) and rice PHYTOCHROME-INTERACTING FACTOR-LIKE 1 (OsPIL1). The overexpression of DREB1A has been reported to improve drought stress tolerance in various crops, although it also causes a severe dwarf phenotype. OsPIL1 is a rice homologue of Arabidopsis PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), and it enhances cell elongation by activating cell wall-related gene expression. We found that the OsPIL1 protein was more stable than PIF4 under light conditions in Arabidopsis protoplasts. Transactivation analyses revealed that DREB1A and OsPIL1 did not negatively affect each other's transcriptional activities. The transgenic plants overexpressing both OsPIL1 and DREB1A showed the improved drought stress tolerance similar to that of DREB1A overexpressors. Furthermore, double overexpressors showed the enhanced hypocotyl elongation and floral induction compared with the DREB1A overexpressors. Metabolome analyses indicated that compatible solutes, such as sugars and amino acids, accumulated in the double overexpressors, which was similar to the observations of the DREB1A overexpressors. Transcriptome analyses showed an increased expression of abiotic stress-inducible DREB1A downstream genes and cell elongation-related OsPIL1 downstream genes in the double overexpressors, which suggests that these two transcription factors function independently in the transgenic plants despite the trade-offs required to balance plant growth and stress tolerance. Our study provides a basis for plant genetic engineering designed to overcome growth retardation in drought-tolerant transgenic plants. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology

  19. Small RNA Profiling of Two Important Cultivars of Banana and Overexpression of miRNA156 in Transgenic Banana Plants

    Science.gov (United States)

    Ganapathi, Thumballi R.

    2015-01-01

    Micro RNAs (miRNAs) are a class of non-coding, short RNAs having important roles in regulation of gene expression. Although plant miRNAs have been studied in detail in some model plants, less is known about these miRNAs in important fruit plants like banana. miRNAs have pivotal roles in plant growth and development, and in responses to diverse biotic and abiotic stress stimuli. Here, we have analyzed the small RNA expression profiles of two different economically significant banana cultivars by using high-throughput sequencing technology. We identified a total of 170 and 244 miRNAs in the two libraries respectively derived from cv. Grand Naine and cv. Rasthali leaves. In addition, several cultivar specific microRNAs along with their putative target transcripts were also detected in our studies. To validate our findings regarding the small RNA profiles, we also undertook overexpression of a common microRNA, MusamiRNA156 in transgenic banana plants. The transgenic plants overexpressing the stem-loop sequence derived from MusamiRNA156 gene were stunted in their growth together with peculiar changes in leaf anatomy. These results provide a foundation for further investigations into important physiological and metabolic pathways operational in banana in general and cultivar specific traits in particular. PMID:25962076

  20. Agrobacterium rhizogenes rolB gene affects photosynthesis and chlorophyll content in transgenic tomato (Solanum lycopersicum L.) plants.

    Science.gov (United States)

    Bettini, Priscilla P; Marvasi, Massimiliano; Fani, Fabiola; Lazzara, Luigi; Cosi, Elena; Melani, Lorenzo; Mauro, Maria Luisa

    2016-10-01

    Insertion of Agrobacterium rhizogenes rolB gene into plant genome affects plant development, hormone balance and defence. However, beside the current research, the overall transcriptional response and gene expression of rolB as a modulator in plant is unknown. Transformed rolB tomato plant (Solanum lycopersicum L.) cultivar Tondino has been used to investigate the differential expression profile. Tomato is a well-known model organism both at the genetic and molecular level, and one of the most important commercial food crops in the world. Through the construction and characterization of a cDNA subtracted library, we have investigated the differential gene expression between transgenic clones of rolB and control tomato and have evaluated genes specifically transcribed in transgenic rolB plants. Among the selected genes, five genes encoding for chlorophyll a/b binding protein, carbonic anhydrase, cytochrome b6/f complex Fe-S subunit, potassium efflux antiporter 3, and chloroplast small heat-shock protein, all involved in chloroplast function, were identified. Measurement of photosynthesis efficiency by the level of three different photosynthetic parameters (Fv/Fm, rETR, NPQ) showed rolB significant increase in non-photochemical quenching and a, b chlorophyll content. Our results point to highlight the role of rolB on plant fitness by improving photosynthesis. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. Small RNA Profiling of Two Important Cultivars of Banana and Overexpression of miRNA156 in Transgenic Banana Plants.

    Directory of Open Access Journals (Sweden)

    Siddhesh B Ghag

    Full Text Available Micro RNAs (miRNAs are a class of non-coding, short RNAs having important roles in regulation of gene expression. Although plant miRNAs have been studied in detail in some model plants, less is known about these miRNAs in important fruit plants like banana. miRNAs have pivotal roles in plant growth and development, and in responses to diverse biotic and abiotic stress stimuli. Here, we have analyzed the small RNA expression profiles of two different economically significant banana cultivars by using high-throughput sequencing technology. We identified a total of 170 and 244 miRNAs in the two libraries respectively derived from cv. Grand Naine and cv. Rasthali leaves. In addition, several cultivar specific microRNAs along with their putative target transcripts were also detected in our studies. To validate our findings regarding the small RNA profiles, we also undertook overexpression of a common microRNA, MusamiRNA156 in transgenic banana plants. The transgenic plants overexpressing the stem-loop sequence derived from MusamiRNA156 gene were stunted in their growth together with peculiar changes in leaf anatomy. These results provide a foundation for further investigations into important physiological and metabolic pathways operational in banana in general and cultivar specific traits in particular.

  2. Small RNA Profiling of Two Important Cultivars of Banana and Overexpression of miRNA156 in Transgenic Banana Plants.

    Science.gov (United States)

    Ghag, Siddhesh B; Shekhawat, Upendra K S; Ganapathi, Thumballi R

    2015-01-01

    Micro RNAs (miRNAs) are a class of non-coding, short RNAs having important roles in regulation of gene expression. Although plant miRNAs have been studied in detail in some model plants, less is known about these miRNAs in important fruit plants like banana. miRNAs have pivotal roles in plant growth and development, and in responses to diverse biotic and abiotic stress stimuli. Here, we have analyzed the small RNA expression profiles of two different economically significant banana cultivars by using high-throughput sequencing technology. We identified a total of 170 and 244 miRNAs in the two libraries respectively derived from cv. Grand Naine and cv. Rasthali leaves. In addition, several cultivar specific microRNAs along with their putative target transcripts were also detected in our studies. To validate our findings regarding the small RNA profiles, we also undertook overexpression of a common microRNA, MusamiRNA156 in transgenic banana plants. The transgenic plants overexpressing the stem-loop sequence derived from MusamiRNA156 gene were stunted in their growth together with peculiar changes in leaf anatomy. These results provide a foundation for further investigations into important physiological and metabolic pathways operational in banana in general and cultivar specific traits in particular.

  3. Astylus atromaculatus (Coleoptera: Melyridae): abundance and role in pollen dispersal in Bt and non-Bt cotton in South Africa.

    Science.gov (United States)

    Pierre, Jacqueline; Hofs, Jean-Luc

    2010-10-01

    In South Africa, modified Bt (Cry1 Ac) cotton cultivars and organic ones coexist. This raises the question of the risk of dissemination of genetically modified (GM) pollen to non-GM crops by visiting insects. We inventoried the flower-visiting insects in Bt and non-Bt cotton fields of the South African Highveld region and investigated their role in pollen dispersal. Their diversity and abundance varied slightly among sites, with Astylus atromaculatus as the predominant insect on both Bt and non-Bt cotton flowers. The other major flower-visiting species were Apis mellifera and solitary Apidae. No differences were found in the abundance of each taxum between Bt and non-Bt cotton except for Scoliidae and Nitidulidae, which were scarce overall (Bt flowers in the central area of the field at one site. The pollen load on A. atromaculatus was as high as on Apis mellifera. Cage tests showed that A. atromaculatus can pollinate female cotton plants by transferring pollen from male donor plants. In the field, the flight range of this insect was generally short (25 m), but it can occasionally reach up to 200 m or even more. This study therefore highlights that A. atromaculatus, commonly regarded as a pest, could be an unexpected but efficient pollinator. Because its population density can be high, this species could mediate unwanted cotton pollen flow when distances between coexiting fields are not sufficient.

  4. Expression of the nos operon proteins from Pseudomonas stutzeri in transgenic plants to assemble nitrous oxide reductase.

    Science.gov (United States)

    Wan, Shen; Mottiar, Yaseen; Johnson, Amanda M; Goto, Kagami; Altosaar, Illimar

    2012-06-01

    Nitrous oxide (N(2)O) is a stable greenhouse gas that plays a significant role in the destruction of the ozone layer. Soils are a significant source of atmospheric N(2)O. It is important to explore some innovative and effective biology-based strategies for N(2)O mitigation. The enzyme nitrous oxide reductase (N(2)OR), naturally found in soil bacteria, is responsible for catalysing the final step of the denitrification pathway, conversion of N(2)O to dintrogen gas (N(2)). To transfer this catalytic pathway from soil into plants and amplify the abundance of this essential mechanism (to reduce global warming), a mega-cassette of five coding sequences was assembled to produce transgenic plants heterologously expressing the bacterial nos operon in plant leaves. Both the single-gene transformants (nosZ) and the multi-gene transformants (nosFLZDY) produced active recombinant N(2)OR. Enzymatic activity was detected using the methyl viologen-linked enzyme assay, showing that extracts from both types of transgenic plants exhibited N(2)O-reducing activity. Remarkably, the single-gene strategy produced higher reductase capability than the whole-operon approach. The data indicate that bacterial N(2)OR expressed in plants could convert N(2)O into inert N(2) without involvement of other Nos proteins. Silencing by homologous signal sequences, or cryptic intracellular targeting are possible explanations for the low activities obtained. Expressing N(2)OR from Pseudomonas stutzeri in single-gene transgenic plants indicated that such ag-biotech solutions to climate change have the potential to be easily incorporated into existing genetically modified organism seed germplasm.

  5. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants

    Science.gov (United States)

    Szalonek, Michal; Sierpien, Barbara; Rymaszewski, Wojciech; Gieczewska, Katarzyna; Garstka, Maciej; Lichocka, Malgorzata; Sass, Laszlo; Paul, Kenny; Vass, Imre; Vankova, Radomira; Dobrev, Peter; Szczesny, Pawel; Marczewski, Waldemar; Krusiewicz, Dominika; Strzelczyk-Zyta, Danuta; Hennig, Jacek; Konopka-Postupolska, Dorota

    2015-01-01

    Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L.) during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin) than wild type (WT). Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII), as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress. PMID:26172952

  6. Detection of nptII (kanamycin resistance) genes in genomes of transgenic plants by marker-rescue transformation.

    Science.gov (United States)

    de Vries, J; Wackernagel, W

    1998-04-01

    We have developed a novel system for the sensitive detection of nptII genes (kanamycin resistance determinants) including those present in transgenic plant genomes. The assay is based on the recombinational repair of an nptII gene with an internal 10-bp deletion located on a plasmid downstream of a bacterial promoter. Uptake of an nptII gene by transformation restores kanamycin resistance. In Escherichia coli, promoterless nptII genes provided by electroporation were rescued with high efficiency in a RecA-dependent recombinational process. For the rescue of nptII genes present in chromosomal plant DNA, the system was adapted to natural transformation, which favours the uptake of linear DNA. When competent Acinetobacter sp. BD413 (formerly A. calcoaceticus) cells containing the mutant nptII gene on a plasmid were transformed with DNA from various transgenic plants carrying nptII as a marker gene (Solanum tuberosum, Nicotiana tabacum, Beta vulgaris, Brassica napus, Lycopersicon esculentum), kanamycin-resistant transformants were obtained roughly in proportion to the concentration of nptII genes in the plant DNA. The rescue of nptII genes occurred in the presence of a more than 6 x 10(6)-fold excess of plant DNA. Only 18 ng of potato DNA (2.5 x 10(3) genome equivalents, each with one copy of nptII) was required to produce one kanamycin-resistant transformant. These experiments and others employing DNA isolated from soil samples demonstrate that the system allows reliable and highly sensitive monitoring of nptII genes in transgenic plant DNA and in DNA from environmental sources, such as soil, without the need for prior DNA amplification (e.g. by PCR).

  7. Generation of marker- and/or backbone-free transgenic wheat plants via Agrobacterium-mediated transformation

    Directory of Open Access Journals (Sweden)

    Wang Genping

    2016-09-01

    Full Text Available Horizontal transfer of antibiotic resistance genes to animals and vertical transfer of herbicide resistance genes to the weedy relatives are perceived as major biosafety concerns in genetically modified (GM crops. In this study, five novel vectors which used gusA and bar as a reporter gene and a selection marker gene, respectively, were constructed based on the pCLEAN dual binary vector system. Among these vectors, 1G7B and 5G7B carried two T-DNAs located on two respective plasmids with 5G7B possessing an additional virGwt gene. 5LBTG154 and 5TGTB154 carried two T-DNAs in the target plasmid with either one or double right borders, and 5BTG154 carried the selectable marker gene on the backbone outside of the T-DNA left border in the target plasmid. In addition, 5BTG154, 5LBTG154 and 5TGTB154 used pAL154 as a helper plasmid which contains Komari fragment to facilitate transformation. These five dual binary vector combinations were transformed into Agrobacterium strain AGL1 and used to transform durum wheat cv Stewart 63. Evaluation of the co-transformation efficiencies, the frequencies of marker-free transgenic plants and integration of backbone sequences in the obtained transgenic lines indicated that two vectors (5G7B and 5TGTB154 were more efficient in generating marker-free transgenic wheat plants with no or minimal integration of backbone sequences in the wheat genome. The vector series developed in this study for generation of marker- and/or backbone-free transgenic wheat plants via Agrobacterium-mediated transformation will be useful to facilitate the creation of ‘clean’ GM wheat containing only the foreign genes of agronomic importance.

  8. Transgenic Cotton Plants Expressing the HaHR3 Gene Conferred Enhanced Resistance to Helicoverpa armigera and Improved Cotton Yield

    OpenAIRE

    Han, Qiang; Wang, Zhenzhen; He, Yunxin; Xiong, Yehui; Lv, Shun; Li, Shupeng; Zhang, Zhigang; Qiu, Dewen; Zeng, Hongmei

    2017-01-01

    RNA interference (RNAi) has been developed as an efficient technology. RNAi insect-resistant transgenic plants expressing double-stranded RNA (dsRNA) that is ingested into insects to silence target genes can affect the viability of these pests or even lead to their death. HaHR3, a molt-regulating transcription factor gene, was previously selected as a target expressed in bacteria and tobacco plants to control Helicoverpa armigera by RNAi technology. In this work, we selected the dsRNA-HaHR3 f...

  9. Transgenic Cotton Plants Expressing Double-stranded RNAs Target HMG-CoA Reductase (HMGR) Gene Inhibits the Growth, Development and Survival of Cotton Bollworms.

    Science.gov (United States)

    Tian, Geng; Cheng, Linlin; Qi, Xuewei; Ge, Zonghe; Niu, Changying; Zhang, Xianlong; Jin, Shuangxia

    2015-01-01

    RNA interference (RNAi) has been developed as a powerful technique in the research of functional genomics as well as plant pest control. In this report, double-stranded RNAs (dsRNA) targeting 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) gene, which catalyze a rate-limiting enzymatic reaction in the mevalonate pathway of juvenile hormone (JH) synthesis in cotton bollworm, was expressed in cotton plants via Agrobacterium tumefaciens-mediated transformation. PCR and Sothern analysis revealed the integration of HMGR gene into cotton genome. RT-PCR and qRT-PCR confirmed the high transcription level of dsHMGR in transgenic cotton lines. The HMGR expression both in transcription and translation level was significantly downregulated in cotton bollworms (helicoverpa armigera) larvae after feeding on the leaves of HMGR transgenic plants. The transcription level of HMGR gene in larvae reared on transgenic cotton leaves was as much as 80.68% lower than that of wild type. In addition, the relative expression level of vitellogenin (Vg, crucial source of nourishment for offspring embryo development) gene was also reduced by 76.86% when the insect larvae were fed with transgenic leaves. The result of insect bioassays showed that the transgenic plant harboring dsHMGR not only inhibited net weight gain but also delayed the growth of cotton bollworm larvae. Taken together, transgenic cotton plant expressing dsRNAs successfully downregulated HMGR gene and impaired the development and survival of target insect, which provided more option for plant pest control.

  10. Constitutive expression of DaCBF7, an Antarctic vascular plant Deschampsia antarctica CBF homolog, resulted in improved cold tolerance in transgenic rice plants.

    Science.gov (United States)

    Byun, Mi Young; Lee, Jungeun; Cui, Li Hua; Kang, Yoonjee; Oh, Tae Kyung; Park, Hyun; Lee, Hyoungseok; Kim, Woo Taek

    2015-07-01

    Deschampsia antarctica is an Antarctic hairgrass that grows on the west coast of the Antarctic peninsula. In this report, we have identified and characterized a transcription factor, D. antarctica C-repeat binding factor 7 (DaCBF7), that is a member of the monocot group V CBF homologs. The protein contains a single AP2 domain, a putative nuclear localization signal, and the typical CBF signature. DaCBF7, like other monocot group V homologs, contains a distinct polypeptide stretch composed of 43 amino acids in front of the AP2 motif. DaCBF7 was predominantly localized to nuclei and interacted with the C-repeat/dehydration responsive element (CRT/DRE) core sequence (ACCGAC) in vitro. DaCBF7 was induced by abiotic stresses, including drought, cold, and salinity. To investigate its possible cellular role in cold tolerance, a transgenic rice system was employed. DaCBF7-overexpressing transgenic rice plants (Ubi:DaCBF7) exhibited markedly increased tolerance to cold stress compared to wild-type plants without growth defects; however, overexpression of DaCBF7 exerted little effect on tolerance to drought or salt stress. Transcriptome analysis of a Ubi:DaCBF7 transgenic line revealed 13 genes that were up-regulated in DaCBF7-overexpressing plants compared to wild-type plants in the absence of cold stress and in short- or long-term cold stress. Five of these genes, dehydrin, remorin, Os03g63870, Os11g34790, and Os10g22630, contained putative CRT/DRE or low-temperature responsive elements in their promoter regions. These results suggest that overexpression of DaCBF7 directly and indirectly induces diverse genes in transgenic rice plants and confers enhanced tolerance to cold stress. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. An Approach Towards Structure Based Antimicrobial Peptide Design for Use in Development of Transgenic Plants: A Strategy for Plant Disease Management.

    Science.gov (United States)

    Ilyas, Humaira; Datta, Aritreyee; Bhunia, Anirban

    2017-01-01

    Antimicrobial peptides (AMPs), also known as host defense peptides (HDPs), are ubiquitous and vital components of innate defense response that present themselves as potential candidates for drug design, and aim to control plant and animal diseases. Though their application for plant disease management has long been studied with natural AMPs, cytotoxicity and stability related shortcomings for the development of transgenic plants limit their usage. Newer technologies like molecular modelling, NMR spectroscopy and combinatorial chemistry allow screening for potent candidates and provide new avenues for the generation of rationally designed synthetic AMPs with multiple biological functions. Such AMPs can be used for the control of plant diseases that lead to huge yield losses of agriculturally important crop plants, via generation of transgenic plants. Such approaches have gained significant attention in the past decade as a consequence of increasing antibiotic resistance amongst plant pathogens, and the shortcomings of existing strategies that include environmental contamination and human/animal health hazards amongst others. This review summarizes the recent trends and approaches used for employing AMPs, emphasizing on designed/modified ones, and their applications toward agriculture and food technology. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Bt crop effects on functional guilds of non-target arthropods: a meta-analysis.

    Science.gov (United States)

    Wolfenbarger, L LaReesa; Naranjo, Steven E; Lundgren, Jonathan G; Bitzer, Royce J; Watrud, Lidia S

    2008-05-07

    Uncertainty persists over the environmental effects of genetically-engineered crops that produce the insecticidal Cry proteins of Bacillus thuringiensis (Bt). We performed meta-analyses on a modified public database to synthesize current knowledge about the effects of Bt cotton, maize and potato on the abundance and interactions of arthropod non-target functional guilds. We compared the abundance of predators, parasitoids, omnivores, detritivores and herbivores under scenarios in which neither, only the non-Bt crops, or both Bt and non-Bt crops received insecticide treatments. Predators were less abundant in Bt cotton compared to unsprayed non-Bt controls. As expected, fewer specialist parasitoids of the target pest occurred in Bt maize fields compared to unsprayed non-Bt controls, but no significant reduction was detected for other parasitoids. Numbers of predators and herbivores were higher in Bt crops compared to sprayed non-Bt controls, and type of insecticide influenced the magnitude of the difference. Omnivores and detritivores were more abundant in insecticide-treated controls and for the latter guild this was associated with reductions of their predators in sprayed non-Bt maize. No differences in abundance were found when both Bt and non-Bt crops were sprayed. Predator-to-prey ratios were unchanged by either Bt crops or the use of insecticides; ratios were higher in Bt maize relative to the sprayed non-Bt control. Overall, we find no uniform effects of Bt cotton, maize and potato on the functional guilds of non-target arthropods. Use of and type of insecticides influenced the magnitude and direction of effects; insecticde effects were much larger than those of Bt crops. These meta-analyses underscore the importance of using controls not only to isolate the effects of a Bt crop per se but also to reflect the replacement of existing agricultural practices. Results will provide researchers with information to design more robust experiments and will inform the

  13. Bt crop effects on functional guilds of non-target arthropods: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    L LaReesa Wolfenbarger

    Full Text Available BACKGROUND: Uncertainty persists over the environmental effects of genetically-engineered crops that produce the insecticidal Cry proteins of Bacillus thuringiensis (Bt. We performed meta-analyses on a modified public database to synthesize current knowledge about the effects of Bt cotton, maize and potato on the abundance and interactions of arthropod non-target functional guilds. METHODOLOGY/PRINCIPAL FINDINGS: We compared the abundance of predators, parasitoids, omnivores, detritivores and herbivores under scenarios in which neither, only the non-Bt crops, or both Bt and non-Bt crops received insecticide treatments. Predators were less abundant in Bt cotton compared to unsprayed non-Bt controls. As expected, fewer specialist parasitoids of the target pest occurred in Bt maize fields compared to unsprayed non-Bt controls, but no significant reduction was detected for other parasitoids. Numbers of predators and herbivores were higher in Bt crops compared to sprayed non-Bt controls, and type of insecticide influenced the magnitude of the difference. Omnivores and detritivores were more abundant in insecticide-treated controls and for the latter guild this was associated with reductions of their predators in sprayed non-Bt maize. No differences in abundance were found when both Bt and non-Bt crops were sprayed. Predator-to-prey ratios were unchanged by either Bt crops or the use of insecticides; ratios were higher in Bt maize relative to the sprayed non-Bt control. CONCLUSIONS/SIGNIFICANCE: Overall, we find no uniform effects of Bt cotton, maize and potato on the functional guilds of non-target arthropods. Use of and type of insecticides influenced the magnitude and direction of effects; insecticde effects were much larger than those of Bt crops. These meta-analyses underscore the importance of using controls not only to isolate the effects of a Bt crop per se but also to reflect the replacement of existing agricultural practices. Results will

  14. Maize (Zea mays)-derived bovine trypsin: characterization of the first large-scale, commercial protein product from transgenic plants.

    Science.gov (United States)

    Woodard, Susan L; Mayor, Jocelyne M; Bailey, Michele R; Barker, Donna K; Love, Robert T; Lane, Jeffrey R; Delaney, Donna E; McComas-Wagner, Janet M; Mallubhotla, Hanuman D; Hood, Elizabeth E; Dangott, Lawrence J; Tichy, Shane E; Howard, John A

    2003-10-01

    Bovine trypsin (EC 3.4.21.4) is an enzyme that is widely used for commercial purposes to digest or process other proteins, including some therapeutic proteins. The biopharmaceutical industry is trying to eliminate animal-derived proteins from manufacturing processes due to the possible contamination of these products by human pathogens. Recombinant trypsin has been produced in a number of systems, including cell culture, bacteria and yeast. To date, these expression systems have not produced trypsin on a scale sufficient to fulfill the need of biopharmaceutical manufacturers where kilogram quantities are often required. The present paper describes commercial-level production of trypsin in transgenic maize (Zea mays) and its physical and functional characterization. This protease, the first enzyme to be produced on a large-scale using transgenic plant technology, is functionally equivalent to native bovine pancreatic trypsin. The availability of this reagent should allow for the replacement of animal-derived trypsin in the processing of pharmaceutical proteins.

  15. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

    Directory of Open Access Journals (Sweden)

    Nadal Anna

    2012-09-01

    Full Text Available Abstract Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER, analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP, had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM

  16. Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness.

    Science.gov (United States)

    Nadal, Anna; Montero, Maria; Company, Nuri; Badosa, Esther; Messeguer, Joaquima; Montesinos, Laura; Montesinos, Emilio; Pla, Maria

    2012-09-04

    The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER), analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der) was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII) transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM) plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP), had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM plants expressing, for example, BP100 based on inverted

  17. Metabolic engineering of dhurrin in transgenic Arabidopsis plants with marginal inadvertent effects on the metabolome and transcriptome.

    Science.gov (United States)

    Kristensen, Charlotte; Morant, Marc; Olsen, Carl Erik; Ekstrøm, Claus T; Galbraith, David W; Møller, Birger Lindberg; Bak, Søren

    2005-02-01

    Focused and nontargeted approaches were used to assess the impact associated with introduction of new high-flux pathways in Arabidopsis thaliana by genetic engineering. Transgenic A. thaliana plants expressing the entire biosynthetic pathway for the tyrosine-derived cyanogenic glucoside dhurrin as accomplished by insertion of CYP79A1, CYP71E1, and UGT85B1 from Sorghum bicolor were shown to accumulate 4% dry-weight dhurrin with marginal inadvertent effects on plant morphology, free amino acid pools, transcriptome, and metabolome. In a similar manner, plants expressing only CYP79A1 accumulated 3% dry weight of the tyrosine-derived glucosinolate, p-hydroxybenzylglucosinolate with no morphological pleitropic effects. In contrast, insertion of CYP79A1 plus CYP71E1 resulted in stunted plants, transcriptome alterations, accumulation of numerous glucosides derived from detoxification of intermediates in the dhurrin pathway, and in loss of the brassicaceae-specific UV protectants sinapoyl glucose and sinapoyl malate and kaempferol glucosides. The accumulation of glucosides in the plants expressing CYP79A1 and CYP71E1 was not accompanied by induction of glycosyltransferases, demonstrating that plants are constantly prepared to detoxify xenobiotics. The pleiotrophic effects observed in plants expressing sorghum CYP79A1 and CYP71E1 were complemented by retransformation with S. bicolor UGT85B. These results demonstrate that insertion of high-flux pathways directing synthesis and intracellular storage of high amounts of a cyanogenic glucoside or a glucosinolate is achievable in transgenic A. thaliana plants with marginal inadvertent effects on the transcriptome and metabolome.

  18. Expression of Helicobacter pylori TonB protein in transgenic Arabidopsis thaliana: toward production of vaccine antigens in plants.

    Science.gov (United States)

    Kalbina, Irina; Engstrand, Lars; Andersson, Sören; Strid, Ake

    2010-10-01

    The aim of this study was to produce a recombinant version of the highly antigenic Helicobacter pylori TonB (iron-dependent siderophore transporter protein HP1341) in transgenic plants as a candidate oral vaccine antigen. Using Agrobacterium-mediated gene transfer, we introduced three different constructs of the tonB gene into the genome of the model plant Arabidopsis thaliana. We investigated transgene insertion by PCR, produced TonB antibodies for analysis of the production of the recombinant protein in plants, verified the identity of the protein produced by mass spectrometry analysis, and analyzed the number of genetic inserts in the plants by Southern blotting. Three different constructs of the expression cassette (full-length tonB, tonB truncated in the 5' end removing the codons for a transmembrane helix, and the latter construct with codons for the endoplasmic reticulum SEKDEL retention signal added to the 3' end) were used to find the most effective way to express the TonB antigen. Production of TonB protein was detected in plants transformed with each of the constructs, confirmed by both Western blotting and mass spectrometry analysis. No considerable differences in protein expression from the three different constructs were observed. The protein concentration in the plants was at least 0.05% of the total soluble proteins. The Helicobacter pylori TonB protein can be produced in Arabidopsis thaliana plants in a form that is recognizable by rabbit anti-TonB antiserum. These TonB-expressing plants are highly suitable for animal studies of oral administration as a route for immunization against Helicobacter infections. © 2010 Blackwell Publishing Ltd.

  19. Ectopic Terpene Synthase Expression Enhances Sesquiterpene Emission in Nicotiana attenuata without Altering Defense or Development of Transgenic Plants or Neighbors1[W

    Science.gov (United States)

    Schuman, Meredith C.; Palmer-Young, Evan C.; Schmidt, Axel; Gershenzon, Jonathan; Baldwin, Ian T.

    2014-01-01

    Sesquiterpenoids, with approximately 5,000 structures, are the most diverse class of plant volatiles with manifold hypothesized functions in defense, stress tolerance, and signaling between and within plants. These hypotheses have often been tested by transforming plants with sesquiterpene synthases expressed behind the constitutively active 35S promoter, which may have physiological costs measured as inhibited growth and reduced reproduction or may require augmentation of substrate pools to achieve enhanced emission, complicating the interpretation of data from affected transgenic lines. Here, we expressed maize (Zea mays) terpene synthase10 (ZmTPS10), which produces (E)-α-bergamotene and (E)-β-farnesene, or a point mutant ZmTPS10M, which produces primarily (E)-β-farnesene, under control of the 35S promoter in the ecological model plant Nicotiana attenuata. Transgenic N. attenuata plants had specifically enhanced emission of target sesquiterpene(s) with no changes detected in their emission of any other volatiles. Treatment with herbivore or jasmonate elicitors induces emission of (E)-α-bergamotene in wild-type plants and also tended to increase emission of (E)-α-bergamotene and (E)-β-farnesene in transgenics. However, transgenics did not differ from the wild type in defense signaling or chemistry and did not alter defense chemistry in neighboring wild-type plants. These data are inconsistent with within-plant and between-plant signaling functions of (E)-β-farnesene and (E)-α-bergamotene in N. attenuata. Ectopic sesquiterpene emission was apparently not costly for transgenics, which were similar to wild-type plants in their growth and reproduction, even when forced to compete for common resources. These transgenics would be well suited for field experiments to investigate indirect ecological effects of sesquiterpenes for a wild plant in its native habitat. PMID:25187528

  20. Non-recessive Bt toxin resistance conferred by an intracellular cadherin mutation in field-selected populations of cotton bollworm.

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    Haonan Zhang

    Full Text Available Transgenic crops producing Bacillus thuringiensis (Bt toxins have been planted widely to control insect pests, yet evolution of resistance by the pests can reduce the benefits of this approach. Recessive mutations in the extracellular domain of toxin-binding cadherin proteins that confer resistance to Bt toxin Cry1Ac by disrupting toxin binding have been reported previously in three major lepidopteran pests, including the cotton bollworm, Helicoverpa armigera. Here we report a novel allele from cotton bollworm with a deletion in the intracellular domain of cadherin that is genetically linked with non-recessive resistance to Cry1Ac. We discovered this allele in each of three field-selected populations we screened from northern China where Bt cotton producing Cry1Ac has been grown intensively. We expressed four types of cadherin alleles in heterologous cell cultures: susceptible, resistant with the intracellular domain mutation, and two complementary chimeric alleles with and without the mutation. Cells transfected with each of the four cadherin alleles bound Cry1Ac and were killed by Cry1Ac. However, relative to cells transfected with either the susceptible allele or the chimeric allele lacking the intracellular domain mutation, cells transfected with the resistant allele or the chimeric allele containing the intracellular domain mutation were less susceptible to Cry1Ac. These results suggest that the intracellular domain of cadherin is involved in post-binding events that affect toxicity of Cry1Ac. This evidence is consistent with the vital role of the intracellular region of cadherin proposed by the cell signaling model of the mode of action of Bt toxins. Considered together with previously reported data, the results suggest that both pore formation and cell signaling pathways contribute to the efficacy of Bt toxins.

  1. Effective dominance of resistance of Spodoptera frugiperda to Bt maize and cotton varieties: implications for resistance management

    Science.gov (United States)

    Horikoshi, Renato J.; Bernardi, Daniel; Bernardi, Oderlei; Malaquias, José B.; Okuma, Daniela M.; Miraldo, Leonardo L.; Amaral, Fernando S. De A. E.; Omoto, Celso

    2016-10-01

    The resistance of fall armyworm (FAW), Spodoptera frugiperda, has been characterized to some Cry and Vip3A proteins of Bacillus thuringiensis (Bt) expressed in transgenic maize in Brazil. Here we evaluated the effective dominance of resistance based on the survival of neonates from selected Bt-resistant, heterozygous, and susceptible (Sus) strains of FAW on different Bt maize and cotton varieties. High survival of strains resistant to the Cry1F (HX-R), Cry1A.105/Cry2Ab (VT-R) and Cry1A.105/Cry2Ab/Cry1F (PW-R) proteins was detected on Herculex, YieldGard VT PRO and PowerCore maize. Our Vip3A-resistant strain (Vip-R) exhibited high survival on Herculex, Agrisure Viptera and Agrisure Viptera 3 maize. However, the heterozygous from HX-R × Sus, VT-R × Sus, PW-R × Sus and Vip-R × Sus had complete mortality on YieldGard VT PRO, PowerCore, Agrisure Viptera, and Agrisure Viptera 3, whereas the HX-R × Sus and Vip-R × Sus strains survived on Herculex maize. On Bt cotton, the HX-R, VT-R and PW-R strains exhibited high survival on Bollgard II. All resistant strains survived on WideStrike, but only PW-R and Vip-R × Sus survived on TwinLink. Our study provides useful data to aid in the understanding of the effectiveness of the refuge strategy for Insect Resistance Management of Bt plants.

  2. Physcomitrella Patens Dehydrins (PpDHNA and PpDHNC Confer Salinity and Drought Tolerance to Transgenic Arabidopsis Plants

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    Qilong Li

    2017-07-01

    Full Text Available Dehydrins (DHNs as a member of late-embryogenesis-abundant (LEA proteins are involved in plant abiotic stress tolerance. Two dehydrins PpDHNA and PpDHNC were previously characterized from the moss Physcomitrella patens, which has been suggested to be an ideal model plant to study stress tolerance due to its adaptability to extreme environment. In this study, functions of these two genes were analyzed by heterologous expressions in Arabidopsis. Phenotype analysis revealed that overexpressing PpDHN dehydrin lines had stronger stress resistance than wild type and empty-vector control lines. These stress tolerance mainly due to the up-regulation of stress-related genes expression and mitigation to oxidative damage. The transgenic plants showed strong scavenging ability of reactive oxygen species(ROS, which was attributed to the enhancing of the content of antioxidant enzymes like superoxide dismutase (SOD and catalase (CAT. Further analysis showed that the contents of chlorophyll and proline tended to be the appropriate level (close to non-stress environment and the malondialdehyde (MDA were repressed in these transgenic plants after exposure to stress. All these results suggest the PpDHNA and PpDHNC played a crucial role in response to drought and salt stress.

  3. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes.

    Science.gov (United States)

    Dutta, Tushar K; Papolu, Pradeep K; Banakar, Prakash; Choudhary, Divya; Sirohi, Anil; Rao, Uma

    2015-01-01

    Root-knot nematodes (Meloidogyne incognita) cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco, and soybean) that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1), was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60-80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants.

  4. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

    Directory of Open Access Journals (Sweden)

    Tushar Kanti Dutta

    2015-04-01

    Full Text Available Root-knot nematodes (Meloidogyne incognita cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco and soybean that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1, was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60-80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants.

  5. Ectopic expression of BdCIPK31 confers enhanced low-temperature tolerance in transgenic tobacco plants.

    Science.gov (United States)

    Luo, Qingchen; Wei, Qiuhui; Wang, Ruibin; Zhang, Yang; Zhang, Fan; He, Yuan; Yang, Guangxiao; He, Guangyuan

    2018-02-01

    Calcineurin B-like protein (CBL), the Ca2+ sensor, and its interacting protein kinases (CIPKs) play essential roles in plants' response to stress. However, few studies have focused on the functions of CIPKs in low-temperature response. In the present study, BdCIPK31, a cold-responsive CIPK in Brachypodium distachyon, was found to participate in low-temperature response. Ectopic expression of BdCIPK31 conferred cold tolerance in transgenic tobaccos. Further analyses indicated that expression of BdCIPK31 improved ROS detoxication and omsoprotectant biosynthesis in transgenic plants under low-temperature treatment, suggesting that the BdCIPK31 functions positively in plant adaption to the cold-induced oxidative and osmotic stresses. Moreover, BdCIPK31 could upregulate the expressions of some representative stress-related genes under cold stress. In conclusion, these findings suggest that BdCIPK31 functions positively in plant cold response. © The Author(s) 2017. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Expression of Cry1Ab and Cry2Ab by a polycistronic transgene with a self-cleavage peptide in rice.

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    Qichao Zhao

    Full Text Available Insect resistance to Bacillus thuringiensis (Bt crystal protein is a major threat to the long-term use of transgenic Bt crops. Gene stacking is a readily deployable strategy to delay the development of insect resistance while it may also broaden insecticidal spectrum. Here, we report the creation of transgenic rice expressing discrete Cry1Ab and Cry2Ab simultaneously from a single expression cassette using 2A self-cleaving peptides, which are autonomous elements from virus guiding the polycistronic viral gene expression in eukaryotes. The synthetic coding sequences of Cry1Ab and Cry2Ab, linked by the coding sequence of a 2A peptide from either foot and mouth disease virus or porcine teschovirus-1, regardless of order, were all expressed as discrete Cry1Ab and Cry2Ab at high levels in the transgenic rice. Insect bioassays demonstrated that the transgenic plants were highly resistant to lepidopteran pests. This study suggested that 2A peptide can be utilized to express multiple Bt genes at high levels in transgenic crops.

  7. Functional components of the bacterial CzcCBA efflux system reduce cadmium uptake and accumulation in transgenic tobacco plants.

    Science.gov (United States)

    Nesler, Andrea; DalCorso, Giovanni; Fasani, Elisa; Manara, Anna; Di Sansebastiano, Gian Pietro; Argese, Emanuele; Furini, Antonella

    2017-03-25

    Cadmium (Cd) is a toxic trace element released into the environment by industrial and agricultural practices, threatening the health of plants and contaminating the food/feed chain. Biotechnology can be used to develop plant varieties with a higher capacity for Cd accumulation (for use in phytoremediation programs) or a lower capacity for Cd accumulation (to reduce Cd levels in food and feed). Here we generated transgenic tobacco plants expressing components of the Pseudomonas putida CzcCBA efflux system. Plants were transformed with combinations of the CzcC, CzcB and CzcA genes, and the impact on Cd mobilization was analysed. Plants expressing PpCzcC showed no differences in Cd accumulation, whereas those expressing PpCzcB or PpCzcA accumulated less Cd in the shoots, but more Cd in the roots. Plants expressing both PpCzcB and PpCzcA accumulated less Cd in the shoots and roots compared to controls, whereas plants expressing all three genes showed a significant reduction in Cd levels only in shoots. These results show that components of the CzcCBA system can be expressed in plants and may be useful for developing plants with a reduced capacity to accumulate Cd in the shoots, potentially reducing the toxicity of food/feed crops cultivated in Cd-contaminated soils. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. The Ca(2+) status of the endoplasmic reticulum is altered by induction of calreticulin expression in transgenic plants

    Science.gov (United States)

    Persson, S.; Wyatt, S. E.; Love, J.; Thompson, W. F.; Robertson, D.; Boss, W. F.; Brown, C. S. (Principal Investigator)

    2001-01-01

    To investigate the endoplasmic reticulum (ER) Ca(2+) stores in plant cells, we generated tobacco (Nicotiana tabacum; NT1) suspension cells and Arabidopsis plants with altered levels of calreticulin (CRT), an ER-localized Ca(2+)-binding protein. NT1 cells and Arabidopsis plants were transformed with a maize (Zea mays) CRT gene in both sense and antisense orientations under the control of an Arabidopsis heat shock promoter. ER-enriched membrane fractions from NT1 cells were used to examine how altered expression of CRT affects Ca(2+) uptake and release. We found that a 2.5-fold increase in CRT led to a 2-fold increase in ATP-dependent (45)Ca(2+) accumulation in the ER-enriched fraction compared with heat-shocked wild-type controls. Furthermore, after treatment with the Ca(2+) ionophore ionomycin, ER microsomes from NT1 cells overproducing CRT showed a 2-fold increase in the amount of (45)Ca(2+) released, and a 2- to 3-fold increase in the amount of (45)Ca(2+) retained compared with wild type. These data indicate that altering the production of CRT affects the ER Ca(2+) pool. In addition, CRT transgenic Arabidopsis plants were used to determine if altered CRT levels had any physiological effects. We found that the level of CRT in heat shock-induced CRT transgenic plants correlated positively with the retention of chlorophyll when the plants were transferred from Ca(2+)-containing medium to Ca(2+)-depleted medium. Together these data are consistent with the hypothesis that increasing CRT in the ER increases the ER Ca(2+) stores and thereby enhances the survival of plants grown in low Ca(2+) medium.

  9. Characterising microbial protein test substances and establishing their equivalence with plant-produced proteins for use in risk assessments of transgenic crops.

    Science.gov (United States)

    Raybould, Alan; Kilby, Peter; Graser, Gerson

    2013-04-01

    Most commercial transgenic crops are genetically engineered to produce new proteins. Studies to assess the risks to human and animal health, and to the environment, from the use of these crops require grams of the transgenic proteins. It is often extremely difficult to produce sufficient purified transgenic protein from the crop. Nevertheless, ample protein of acceptable purity may be produced by over-expressing the protein in microbes such as Escherichia coli. When using microbial proteins in a study for risk assessment, it is essential that their suitability as surrogates for the plant-produced transgenic proteins is established; that is, the proteins are equivalent for the purposes of the study. Equivalence does not imply that the plant and microbial proteins are identical, but that the microbial protein is sufficiently similar biochemically and functionally to the plant protein such that studies using the microbial protein provide reliable information for risk assessment of the transgenic crop. Equivalence is a judgement based on a weight of evidence from comparisons of relevant properties of the microbial and plant proteins, including activity, molecular weight, amino acid sequence, glycosylation and immuno-reactivity. We describe a typical set of methods used to compare proteins in regulatory risk assessments for transgenic crops, and discuss how risk assessors may use comparisons of proteins to judge equivalence.

  10. Ocorrência do ácaro fitófago Catarhinus tricholaenae Keifer (Acari: Diptilomiopidae em cultivares de milho Bt Occurrence of the phytophagous mite Catarhinus tricholaenae Keifer (Acari: Diptilomiopidae on Bt corn cultivars

    Directory of Open Access Journals (Sweden)

    Marcos Antônio Matiello Fadini

    2012-09-01

    (b and 1063 individuals on leaves of non-Bt cultivars. The highest average population abundances occurred in the months of November and December. Factors of plant phenological stage and rainfall positively affected the abundance of C. tricholaenae. The average abundance of the collection period of C. tricholaenae was reduced by cultivar corn containing Cry 1 A (b protein. This is the first report of mites on the cultivars of transgenic corn in Brazil.

  11. Transgenic Cotton Plants Expressing Cry1Ia12 Toxin Confer Resistance to Fall Armyworm (Spodoptera frugiperda) and Cotton Boll Weevil (Anthonomus grandis)

    Science.gov (United States)

    de Oliveira, Raquel S.; Oliveira-Neto, Osmundo B.; Moura, Hudson F. N.; de Macedo, Leonardo L. P.; Arraes, Fabrício B. M.; Lucena, Wagner A.; Lourenço-Tessutti, Isabela T.; de Deus Barbosa, Aulus A.; da Silva, Maria C. M.; Grossi-de-Sa, Maria F.

    2016-01-01

    Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized by PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold). Also, an important reduction of Anthonomus grandis emerging adults (up to 60%) was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda), and the Coleopteran (A. grandis) insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests. PMID:26925081

  12. Transgenic cotton plants expressing Cry1Ia12 toxin confer resistance to fall armyworm (Spodoptera frugiperda and cotton boll weevil (Anthonomus grandis

    Directory of Open Access Journals (Sweden)

    Raquel Sampaio Oliveira

    2016-02-01

    Full Text Available Gossypium hirsutum (commercial cooton is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized with PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold. Also, a significant reduction of Anthonomus grandis emerging adults (up to 60% was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda and the Coleopteran (A. grandis insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests.

  13. Transgenic Cotton Plants Expressing Cry1Ia12 Toxin Confer Resistance to Fall Armyworm (Spodoptera frugiperda) and Cotton Boll Weevil (Anthonomus grandis).

    Science.gov (United States)

    de Oliveira, Raquel S; Oliveira-Neto, Osmundo B; Moura, Hudson F N; de Macedo, Leonardo L P; Arraes, Fabrício B M; Lucena, Wagner A; Lourenço-Tessutti, Isabela T; de Deus Barbosa, Aulus A; da Silva, Maria C M; Grossi-de-Sa, Maria F

    2016-01-01

    Gossypium hirsutum (commercial cooton) is one of the most economically important fibers sources and a commodity crop highly affected by insect pests and pathogens. Several transgenic approaches have been developed to improve cotton resistance to insect pests, through the transgenic expression of different factors, including Cry toxins, proteinase inhibitors, and toxic peptides, among others. In the present study, we developed transgenic cotton plants by fertilized floral buds injection (through the pollen-tube pathway technique) using an DNA expression cassette harboring the cry1Ia12 gene, driven by CaMV35S promoter. The T0 transgenic cotton plants were initially selected with kanamycin and posteriorly characterized by PCR and Southern blot experiments to confirm the genetic transformation. Western blot and ELISA assays indicated the transgenic cotton plants with higher Cry1Ia12 protein expression levels to be further tested in the control of two major G. hirsutum insect pests. Bioassays with T1 plants revealed the Cry1Ia12 protein toxicity on Spodoptera frugiperda larvae, as evidenced by mortality up to 40% and a significant delay in the development of the target insects compared to untransformed controls (up to 30-fold). Also, an important reduction of Anthonomus grandis emerging adults (up to 60%) was observed when the insect larvae were fed on T1 floral buds. All the larvae and adult insect survivors on the transgenic lines were weaker and significantly smaller compared to the non-transformed plants. Therefore, this study provides GM cotton plant with simultaneous resistance against the Lepidopteran (S. frugiperda), and the Coleopteran (A. grandis) insect orders, and all data suggested that the Cry1Ia12 toxin could effectively enhance the cotton transgenic plants resistance to both insect pests.

  14. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants

    Directory of Open Access Journals (Sweden)

    Daisuke eTodaka

    2015-02-01

    Full Text Available Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water. Numerous transgenic rice plants showing enhanced drought tolerance have been developed to date. Such genetically engineered plants have generally been developed using genes encoding proteins that control drought regulatory networks. These proteins include transcription factors, protein kinases, receptor-like kinases, enzymes related to osmoprotectant or plant hormone synthesis, and other regulatory or functional proteins. Of the drought-tolerant transgenic rice plants described in this review, approximately one-third show decreased plant height under non-stressed conditions or in response to abscisic acid treatment. In cereal crops, plant height is a very important agronomic trait directly affecting yield, although the improvement of lodging resistance should also be taken into consideration. Understanding the regulatory mechanisms of plant growth reduction under drought stress conditions holds promise for developing transgenic plants that produce high yields under drought stress conditions. Plant growth rates are reduced more rapidly than photosynthetic activity under drought conditions, implying that plants actively reduce growth in response to drought stress. In this review, we summarize studies on molecular regulatory networks involved in response to drought stress. In a separate section, we highlight progress in the development of transgenic drought-tolerant rice plants, with special attention paid to field trial investigations.

  15. Recent advances in the dissection of drought-stress regulatory networks and strategies for development of drought-tolerant transgenic rice plants

    Science.gov (United States)

    Todaka, Daisuke; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

    2015-01-01

    Advances have been made in the development of drought-tolerant transgenic plants, including cereals. Rice, one of the most important cereals, is considered to be a critical target for improving drought tolerance, as present-day rice cultivation requires large quantities of water and as drought-tolerant rice plants should be able to grow in small amounts of water.