Transgenic Insect-resistant Cotton Research Articles

A 2-Year Field Study Shows Little Evidence That the Long-Term Planting of Transgenic Insect-Resistant Cotton Affects the Community Structure of Soil Nematodes

Transgenic insect-resistant cotton has been released into the environment for more than a decade in China to effectively control the cotton bollworm (Helicoverpa armigera) and other Lepidoptera. Because of concerns about undesirable ecological side-effects of transgenic crops, it is important to monitor the potential environmental impact of transgenic insect-resistant cotton after commercial release. Our 2-year study included 1 cotton field where non-transgenic cotton had been planted continuously and 2 other cotton fields where transgenic insect-resistant cotton had been planted for different lengths of time since 1997 and since 2002. In 2 consecutive years (2009 and 2010), we took soil samples from 3 cotton fields at 4 different growth stages (seedling, budding, boll-forming and boll-opening stages), collected soil nematodes from soil with the sugar flotation and centrifugation method and identified the soil nematodes to the genus level. The generic composition, individual densities and diversity indices of the soil nematodes did not differ significantly between the 2 transgenic cotton fields and the non-transgenic cotton field, but significant seasonal variation was found in the individual densities of the principal trophic groups and in the diversity indices of the nematodes in all 3 cotton fields. The study used a comparative perspective to monitor the impact of transgenic insect-resistant cotton grown in typical ‘real world’ conditions. The results of the study suggested that more than 10 years of cultivation of transgenic insect-resistant cotton had no significant effects–adverse or otherwise–on soil nematodes. This study provides a theoretical basis for ongoing environmental impact monitoring of transgenic plants.

Root exudates of transgenic cotton and their effects on Fusarium oxysporum

The components of the root exudates from two transgenic insect-resistant cotton lines and their parental cotton lines, and their effects on the growth ofFusarium oxysporumwere investigated. The results demonstrated that the resistance of transgenic insect-resistant cotton toF. oxysporumwas significantly reduced compared with their parental lines. Likewise, the root exudates from transgenic insect-resistant cotton significantly promoted the spore germination and mycelial growth of cottonF. oxysporum. The types of compounds found in the root exudates of transgenic insect-resistant cotton were similar to those of the parental cotton, but the composition and relative content of the compounds were different. The type and content of the fatty acids and esters were significantly reduced in the root exudates of the transgenic insect-resistant cotton, as were certain specific materials, whereas several alkanes were increased. The inhibition of the soil-borne pathogenF. oxysporumcaused by the root exudates from the transgenic insect-resistant cotton was decreased compared with the parental cotton. This result provides a scientific basis for the decline in disease resistance in transgenic insect-resistant cotton.

风向因素对转基因抗虫棉花基因漂移效率的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 风向因素对转基因抗虫棉花基因漂移效率的影响 DOI: 10.5846/stxb201207040932 作者: 作者单位: 中国农业大学昆虫学系,中国农业大学昆虫学系,中国农业大学昆虫学系,中国农业大学昆虫学系,中国农业大学昆虫学系 作者简介: 通讯作者: 中图分类号: 基金项目: 转基因生物新品种培育科技重大专项（2011ZX0811-002） The influence of wind direction on pollen-mediated gene flow in transgenic insect-resistant cotton Author: Affiliation: Department of Entomology,China Agricultural University,Department of Entomology,China Agricultural University,Department of Entomology,China Agricultural University,Department of Entomology,China Agricultural University,Department of Entomology,China Agricultural University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:在转基因作物获准进行环境释放并实行大面积商品化推广的同时，基因漂移所引起的生态环境安全问题不容忽视。以含有双价抗虫基因（Bt/CpTI）的转基因棉花SGK321为花粉供体材料，以常规非转基因棉花品种石远321、中棉35、吉扎1号为花粉受体材料，在温室中人工创造定向风和非定向风条件，应用PCR与蛋白检测相结合的方法，检测外源基因发生基因漂移的效率。结果表明：随着与转基因棉花SGK321距离的增加，外源基因转移至非转基因棉花的基因漂移频率呈现波动性变化。在定向风处理中，基因漂移频率在距离转基因棉花6.4m处达到峰值33.33%，在测定范围内基因漂移最远距离为25.6m；而在非定向风处理中，基因漂移频率在距离转基因棉花12.8m处达到峰值36.67%，在测定范围内基因漂移最远距离为36m。非定向风可显著提高转移至海岛棉吉扎1号的基因漂移频率。外源基因从SGK321转移至其非转基因亲本石远321的基因漂移频率显著高于转移至陆地棉中棉35和海岛棉吉扎1号的漂移频率。为转基因棉花的生态安全性分析提供一定的理论参考价值。 Abstract:With the extensive environment release and large scale cultivation of genetically modified (GM) crops, the ecological environment security problems, caused by transgene escape from GM crop to its non-GM counterpart and wild relatives, have appeared gradually. During the early years of breeding and seed increase, there are some uncertainty among regulators about containment measures needed to prevent the movement of regulated GM traits into adjacent fields and possibly into the human or animal food chain. Cotton, one of the wind-pollinated and highly outcrossing cash crops, is planted on millions of hectares annually and is the third most abundant GM crop. This study investigated the occurrence of gene flow from transgenic cotton to non-transgenic cottons under closed conditions using an insect-resistant gene as a tracer marker. The selectable marker used in this study was the synthetic GFM CryⅠA(C)gene which encoded Bt insecticidal protein with resistance to cotton bollworm. In order to determine the impacts of wind direction on pollen-mediated gene flow (PGF), two greenhouse experiments under different wind conditions (directed and indirected) were establishied. The growth area for each treatment was 480m2, and the row and plant spacing was 80cm×30cm. To observe the frequency and distance of gene flow, the transgenic cotton, SGK321 (Gossypium hirsutum L.), was used as a pollen donor, and conventional varieties Shiyuan321 (Gossypium hirsutum L.), Zhongmian35 (Gossypium hirsutum( L.) and Jizha1 (Gossypium barbadense L.) were applied as pollen recipients, separately. Following natural pollination under the wind conditions, the seeds were collected from each conventional varieties at varying distances and sown in pot culture. DNAs were extracted by the CTAB procedure during cotyledon period, then screened for CryⅠA(C) gene by PCR assays. The positive samples in the PCR assays were identified for Bt insecticidal protein by dipstick assay. The results showed that there was a variation of PGF with increasing distances from the donor plots. The highest frequencies of gene flow were (33.33±12.02)% at 6.4m in thg directed-wind treatment and (36.67±6.67)% at 12.8 m in the indirected-wind treatment. The maximal gene flow distance observed were 25.6m in the directed-wind treatment and 36m in the indirected-wind treatment. PGF to the island cotton (Jizha1) was higher under the indirected-wind treatment than that under the directed-wind treatment, associated with the possibility that the gargantuan island cotton could hinder the wind, leading to cross pollination. PGF to non-transgenic counterpart (Shiyuan321) was obviously higher than those to the island cotton (Jizha1) and the upland cotton (Zhongmian35), indicating that genetic relationship played an important role in cross-pollination with non-GM crops. Such control by individual factor (wind direction) under closed conditions in affecting the occurrence of gene flow rather than open-field trial designs could also be proved very useful in studying the influence of a certain factor on the gene flow. Our research may provide some reference value for the ecological safety assessment of transgenic cotton with the aim of establishing strategies to prevent pollen dispersal. 参考文献 相似文献 引证文献

Effects of Transgenic Bt+CpTI Cotton on Field Abundance of Non-Target Pests and Predators in Xinjiang, China

Transgenic insect-resistant cotton is being increasingly planted in Xinjiang cotton-planting regions, where geographical climate conditions and species composition of pests and natural enemies are greatly unique in China. Limited studies have been conducted on the ecological impacts of transgenic insect-resistant cotton, especially for transgenic double genes (Bt+CpTI) cotton, in this region. In this study, the potential effects of transgenic Bt+CpTI cotton on the seasonal abundance of non-target pests and predators were assessed from 2009 to 2011 in Korla, Xinjiang. The results showed that species composition and seasonal abundance of 5 groups of pests and 5 groups of predators were not significantly different between transgenic Bt+CpTI cotton and non-transgenic cotton every year. It suggests that transgenic Bt+CpTI cotton per se does not affect the population dynamics of non-target pests and predators on this crop in Xinjiang.

Indian entrepreneurship in biotechnology comes of age

Biotechnology is one of the fastest growing, knowledge-driven industries in India and is expected to play a key role in shaping India’s rapidly developing economy. Since its inception in 1986 the Department of Biotechnology (DBT) has been guiding to foster growth of Indian biotechnology with a range of initiatives. Indian biotechnology industry registered over 3.0 billion USD revenue generation in 2009–10, which constitutes about 2 % share of the global biotechnology market. More than 300 companies are engaged in different biotechnology sectors in India, majority of which are clustered in western and southern regions. Biopharmaceuticals is the largest biotechnology sector in India with about 62 % market share. Bioservices ranked second due to the upward trend in a range of service oriented research activities. Bioagriculture recorded highest growth in 2009–10 and is dominated by insect resistant transgenic cotton. Bioindustrial, which deals with production of enzymes for different industrial uses, is the smallest biotechnology sector in India with 6 % revenue share.

Comparison of chemical composition of different transgenic insect-resistant cotton seeds using Fourier transform infrared spectroscopy (FTIR)

The comparison of chemical composition of genetic modification (GM) crops to their conventional counterparts forms the basis of safety assessment process for GM crops. In this study, we used Fourier transform infrared spectroscopy (FTIR) to detect the chemical and conformational changes between transgenic cotton seeds and their non-transgenic counterparts. The assignment of absorption bands and comparison in band areas of four regions from original FTIR spectra indicated that the contents of the compounds did not differ significantly between transgenic cotton seeds and their non-transgenic counterparts (P > 0.05). The comparison of Fourier self-deconvolution (FSD) and after peak-smoothing spectra in the region between 2000 and 1000 cm-1showed that the differences in band pattern can be observed obviously between transgenic cotton seeds and its counterpart, depending on the varieties. The changes in the protein profile of transgenic Bacillus thuringiensis (Bt) cotton seeds Z30 were significant, both in multi-peaks-fitted protein structures and its ratios, compared with non-transgenic cotton seeds Z16 (P < 0.05). However, transgenic Bt + cowpea trypsin inhibitor (CpTI) cotton seeds SGK321, did not show significant changes, in comparison with non-transgenic cotton seeds SY321. These results indicated that both the indigenous and exogenous proteins structural changes in genetically modified organism (GMO) are worth being detected in detail for research related to its’ safety assessment. Key words: Transgenic, cotton seeds, safety assessment, Fourier transform infrared spectroscopy (FTIR).

Analysis of Integrated Structure of the Exogenous Gene Insertion and the Establishment of Event-specific Detection Method in Transgenic Insect Resistant Cotton

In this study, the complete sequence of exogenous DNA insertion was obtained from transgenic cotton line 06N-119 by using 3'-terminal high-efficiency thermal asymmetric interlaced PCR (hiTAIL-PCR) two times, 5'-terminal hiTAIL-PCR four times and long distance PCR (LD-PCR) once. The insertion of the exogenous gene is 11578 bp in length and consists of the Nptâ…i gene expression cassette and the Bt gene expression cassette in series. There is a 75 bp fragment lost at insertion site but no gene recombination occurred. The event-specific qualitative PCR method was established based on the 3'-terminal flanking sequence, which was proved to be highly specific and sensitive. The detection limit was as low as 0.05% every 100 ng of template, that is equivalent 11 target sequence copies. The results of this study would be importance on the detection of exogenous gene in transgenic cotton and biosafety assessment.

Development of insect-resistant transgenic cotton with chimeric TVip3A* accumulating in chloroplasts

An optimized vip3A gene, designated as vip3A* was chemically synthesized and a thi1 gene chloroplast transit peptide coding sequence was attached to its 5' end to produce the tvip3A*. vip3A* and tvip3A* genes were transformed into Gossypium hirsutum cv. Zhongmiansuo35. Of 42 independent transformants, 36 were positive for the vip3A* or tvip3A* gene. Four independent transgenic T1 lines with single-copy insertions and unchanged phenotypes (CTV1 and CTV2 for tvip3A*, and CV1 and CV2 for vip3A*) were selected by Southern blotting, and subjected to an insect bioassay and field assessment. Four homozygous T2 transgenic lines were then selected and the amount of expressed Vip3A* protein was determined by western blotting and ELISA. The protein concentrations of CTV1 and CTV2 were about three-fold higher than those of CV1 and CV2. As expected, the Vip3A* protein of CTV1 and CTV2 were transported to the chloroplasts, where they accumulated. The Vip3A* protein concentration in the chloroplasts of CTV1 and CTV2 was about 15-fold of that of CV1 and CV2. All four transgenic lines showed 100% mortality against fall armyworm (Spodoptera frugiperda) and beet armyworm (Spodoptera exigua) by insect bioassay. Moreover, CTV1 and CTV2 exhibited 100% mortality against cotton bollworm (CBW, Helicoverpa zea), whereas CV1 and CV2 showed 75.0% and 72.5% mortality against CBW, respectively. The field bioassay indicated that CTV1 and CTV2 were more resistant to CBW than CV1 and CV2. Our results suggest that the two tvip3A* transgenic lines (CTV1 and CTV2) can be used to develop insect-resistant cultivars and could be used as a resource for raising multi-toxins-expressing transgenic cotton.

GENOTYPIC VARIATIONS IN POTASSIUM UPTAKE AND UTILIZATION IN COTTON

Genotypic differences in potassium (K) uptake and utilization were compared for eight cotton cultivars in growth chamber and field experiments. Four of the cultivars (‘SGK3’, ‘SCRC18’, ‘SCRC21’ and ‘SCRC22’) typically produce lower dry mass and the other four (‘Nannong8’, ‘Xiangza2’, ‘Xinluzao12’ and ‘Xiangza3’) produce greater dry mass in K-deficient solution (0.02 mM). The mean dry weight of seedlings (five-leaf stage) of cultivars with greater biomass was 155% higher than that of cultivars with lower biomass yield under K deficiency. However, all the genotypes had similar dry matter yields in K-sufficient solution (2.5 mM). Thus, the four cultivars with superior biomass yield under low K medium may be described as K efficient cultivars while the inferior cultivars may be described as K inefficient. Although seeds of the studied cultivars originated from different research institutes or seed companies, there were little differences in seed K content among them, irrespective of their K efficiency. Consequently, there were no significant differences in K accumulation in seedlings (4 d after germination in a K-free sand medium) just before transferring to nutrient solutions. However, the K efficient genotypes, on average, accumulated twice as much K at 21 d after transferring to K-deficient solution (0.02 mM). A much larger root system as well as a slightly higher uptake rate (K uptake per unit of root dry weight) may have contributed to the higher net K uptake by the K efficient cultivars. In addition, the K efficiency ratio (dry mass produced per unit of K accumulated) and K utilization efficiency (dry mass produced per unit of K concentration) of the K efficient cultivars exceeded those of the K inefficient genotypes by 29% and 234%, respectively, under K deficiency. On average, the K efficient cultivars produced 59% more potential economic yield (dry weight of all reproductive organs) under field conditions even with available soil K at obviously deficient level (60 mg kg−1). We noted especially that the four K inefficient cultivars studied were all transgenic insect-resistant cotton, suggesting that the introduction of foreign genes (Bt and CpTI) may affect the K use efficiency of cotton.

No evidence of persistent effects of continuously planted transgenic insect-resistant cotton on soil microorganisms

Transgenic insect-resistant cotton expressing the Cry1Ac and/or CpTI protein has been released into the environment for commercial cultivation for over a decade in China. In this consecutive 3-year field study (2007–2009), we characterized the microbial populations in two different transgenic cotton fields and one non-transgenic cotton field to assess the environmental impact of long-term cultivation of transgenic insect-resistant plants in credible field conditions. We obtained samples at four different growth stages of cotton (seedling, budding, boll forming and boll opening). The results showed significant seasonal variation in the number of bacteria, fungi, azotobacter, denitrifying bacteria and ammonia-oxidizing bacteria and in diversity indices of microorganisms, but no significant difference in the number of each microbial population or diversity indices attributable to long-term cultivation of transgenic cotton.

Bivalent Insect-Resistant Gene Transgenic Cotton Variety CCRI 41 with High Efficiency and Broad Aadaptability

Bollwarm has been a serious problem in cotton production in China since the 1990th. To breed transgenic pest-resistant cotton variety is one of the most economic measures. Bivalent insect-resistant Bt + CpTI gene transgenic cotton variety possesses stronger pest resistance compared with Bt cotton. CCRI 41 is an insect-resistant gene transgenic cotton variety bred by Cotton Research Institute, Chinese Academy of Agricultural Sciences. A bivalent insect-resistant Bt+CpTI gene was transformed into a high-performance conventional cotton variety, and stable and high-performance transgenic lines were selected using stress-resistance screening and molecular assistant selection strategies. It was the first national released bivalent insect-resistant transgenic cotton variety in China. The cumulative extension acreage of CCRI 41 has reached 3 million ha extensive popularization of CCRI 41 since 2002 in 6 provinces in Yellow River Valley and has reaped economic benefits of 4.5 billion RMB yuan in total. These scientific achievements won the 2009 State Science and Technology Awards of China (2nd prize).

Single leaves photosynthetic characteristics of two insect-resistant transgenic cotton (Gossypium hirsutum L.) varieties in response to light

How the photosynthetic characteristics of insect-resistant transgenic cotton (Gossypium hirsutum L.) respond to light or whether this genetic transformation could result in unintended effects on their photosynthetic and physiological processes is not well known. Two experiments were conducted to investigate the shapes of net photosynthetic rate (PN), stomatal conductance (gs), apparent light use efficiency (LUEapp) and water use efficiency (WUE) light-response curves for single leaves of Bt (Bacillus thuringiensis) and Bt+CpTI (cowpea trypsin inhibitor) transgenic cotton plants and their non-transgenic counterparts, respectively. Results showed that the significant difference in response of PN and WUE to light between transgenic cotton and non-transgenic cotton occured but not always throughout the growing season or in different experiments or for all transgenic cotton lines. It was highly dependent on growth stage, culture condition and variety, but no obvious difference between any transgenic cotton and non-transgenic cotton in the shapes of gs and LUEapp light-response curves was observed in two experiments at different growth stages. In the field experiments, transgenic Bt+CpTI cotton was less sensitive to response of PN to high irradiance at the boll-opening stage. In pot experiments, WUE light-response curves of both Bt transgenic cotton and Bt+CpTI transgenic cotton progressively decreased whereas non-transgenic cotton slowly reached a maximum at high irradiance at boll-opening stage. We supposed that culture environment could affect the photosynthesis of transgenic cotton both directly and indirectly through influencing either foreign genes expression or growth and physiological processes.

Assessing effects of transgenic Cry1Ac cotton on the earthworm Eisenia fetida

Transgenic insect-resistant cotton containing a synthetic version of the insecticidal toxin gene from Bacillus thuringiensis subsp. kurstaki has been planted in China in a large scale and may have adverse impacts on soil organisms. The leaves of the transgenic cotton and the non-transgenic parental cotton were collected and their impacts on the earthworm, Eisenia fetida, were tested in laboratory studies. No significant acute toxicity on E. fetida from oral exposure to the transgenic cotton line, GK19, was detected. The average weight, numbers of cocoons and new offsprings of E. fetida in the GK19 groups were all higher than in the Simian3 groups, but the differences were not significant.

Difference and Its Mechanism in Tolerance to Low-Potassium between Liaomian 18 and NuCOTN99B at Seedling Stage

Exploiting genetic diversity of cotton in tolerance to low-potassium(K) is desired for sustainable production.The objective of the present study was to compare the variation in tolerance to low-K between Liaomian 18,a non-insect-resistant cotton cultivar,and NuCOTN99B,a transgenic insect-resistant cotton cultivar from American,hydroponically grown in growth chamber and to elucidate the underlying mechanisms controlling that.When K application was sufficient(2.5 mmol L?1),there was no significant difference in dry matter yield between the two cultivars at seedling-stage.However,Liaomian 18 produced 170% more dry matter than NuCOTN99B under low K(0.03 mmol L?1) growing condition,suggesting that Liaomian 18 is K-efficiency with higher tolerance to low-K and NuCOTN99B is K-inefficiency.It was observed that K uptake amount per unit root dry weight,per unit root length and per unit root surface area in Liaomian 18 was similar to or lower than that in NuCOTN99B,implying that the K uptake ability concerning physiological aspect of Liaomian 18 was not superior.Furthermore,the ratio of K accumulation in leaf to that in whole plant was 57.7% for Liaomian 18,and 67.6% for NuCOTN99B,which suggested that the K translocation efficiency in Liaomian 18 was ineffective,when compared to NuCOTN99B.Nevertheless,Liaomian 18 had a large root system;its root length,root surface area and root volume were equal to 3.4-,3.8-,and 4.2-fold of those of NuCOTN99B,respectively.Moreover,the index of K utilization(dry matter produced per unit of K concentration) in Liaomian 18 was 147% higher than that in NuCOTN99B.Therefore,the high tolerance to low-K of Liaomian 18 possibly depended on its large root system and efficient internal K utilization instead of its K uptake ability per unit of root dry weight/length/surface area and K translocation efficiency in plant.Because there were no significant differences in osmotic potential as well as relative water content in leaf between Liaomian 18 and NuCOTN99B,it was concluded that the difference in internal K utilization efficiency between the two cultivars was not related to the biophysical function of K(regulation of turgor pressure and osmotic potential),but likely related to the biochemical function of K(promotion of photosynthesis,phloem loading,and protein synthesis etc.).

The effect of root exudates from two transgenic insect-resistant cotton lines on the growth of Fusarium oxysporum

The attenuation of disease resistance in transgenic insect-resistant cotton has become one of the important factors restricting cotton production in China. Two transgenic insect-resistant cotton lines and their parental conventional cotton lines were used as the testing materials. The effects of root exudates of these cotton lines on the spore germination and mycelial growth of Fusarium oxysporum were studied and the components, contents of amino acids and sugars were determined. The results showed that the resistance of the two insect-resistant cotton lines to F. oxysporum was inferior to the parental lines, and that their root exudates promoted fungal spore germination and mycelial growth. Considerable differences in the components and contents of both, amino acids and sugars were found between the root exudates of transgenic cotton lines and their parental lines, where the disease indices were highly correlated with the total amount of sugars in the root exudates.

The oral toxicity of the transgenic Bt+CpTI cotton pollen to honeybees ( Apis mellifera)

Transgenic insect-resistant cotton has been planted in China in a large scale and may have adverse impacts on honeybees. Pollens from the transgenic Cry1Ac+CpTI cotton Zhong-41 and the parental cotton Zhong-23 were collected from the field and their impacts on adult worker bees were assessed. Experimental results showed that Zhong-41 pollen had no acute oral toxic effect on worker bees. No significant differences were observed in the superoxide dismutase activity or in the longevity of worker bees fed with diets containing the two cotton pollens. The main reasons for the outcome may be the low expression level of the transgenic proteins Cry1Ac and CpTI in the pollen of Zhong-41 as well as the substantial equivalence in the amounts of gross protein and soluble saccharides for the two cotton pollens. The implications of these results are discussed and further work to be carried out is put forward.

Development of insect resistant transgenic cotton lines expressing cry1EC gene from an insect bite and wound inducible promoter

Transgenic cotton lines were developed for high-level expression of a synthetic cry1EC gene from a wound inducible promoter. The tobacco pathogenesis related promoter PR-1a was modified by placing CaMV35S promoter on its upstream in reverse orientation. The resultant chimeric promoter CaMV35S(r)PR-1a expressed constitutively and was further up-regulated at the site of feeding by insects. It was induced more rapidly by treatment with salicylic acid (SA). The CaMV35S(r)PR-1a cry1EC expressing transgenic lines of cotton showed 100% mortality of Spodoptera litura larvae. The tightly regulated low-level expression of PR-1a was modified to a highly expressing constitutive expression by CaMV35S placed in reverse orientation. Salicylic acid treatment and wounding enhanced the expression further by the chimeric promoter. The leaves expressed more δ-endotoxin around the sites of insect bites. The levels of expression and induction varied among different transgenic lines, suggesting position effect. Some of the transgenic lines that expressed Cry1EC from the chimeric promoter at a low level also showed 100% mortality when induced with salicylic acid. A highly expressing insect bite and wound inducible promoter is desirable for developing insect resistant transgenic plants.

Differential Responses of Conventional and Bt-Transgenic Cotton to Potassium Deficiency

ABSTRACT Bacillus thuringensis (Bt) transgenic (insect-resistant) cotton cultivars senesce prematurely under potassium (K+) deficiency, more often than conventional cultivars, in the North China Plain. To verify if Bt-transgenic cotton was more susceptible to K+ deficit, two transgenic cultivars, ‘CCRI 41’ and ‘DP 99B’, and two conventional cultivars, ‘CCRI 35’ and ‘CCRI 36’, selected from widely used cultivars in China, were used in a seedling hydroponic study. The culture solution K+ concentration was 0.5 mM for high K+ and 0.02 mM for low K+ conditions. Seedlings of all four cultivars accumulated more dry matter and K+ when grown at high K+ than low K+ conditions. However, under low K+ condition, the dry weight and K+ content of Bt-transgenic cultivars CCRI 41 and DP 99B were lower than those of the conventional cultivars CCRI 36 and CCRI 35. The results indicated that Bt-transgenic cultivars CCRI 41 and DP 99B were more sensitive to K+ deficiency than conventional cultivars CCRI 36 and CCRI 35, which could be the reason for premature senescence symptoms observed from fields of Bt-transgenic cotton under K+ deficiency. Seedlings of all four cultivars had a higher K+ use efficiency (KUE) under low K+ than high K+ conditions, but the KUE did not account for the differential responses between Bt-transgenic and conventional cultivars at the low K+ concentration. The K+ depletion results did not reveal the mechanism for the above differential responses in Vmax and Km of the seedlings either. Further experiments with more cultivars are needed to clarify the differential mechanisms in these genotypes.

BIOCENTURY, outrunner of China's biological technology in agriculture Biocentury Transgene (China) Co., Ltd.

Biotechnology JournalVolume 1, Issue 11 p. 1203-1204 Company profileFree Access BIOCENTURY, outrunner of China's biological technology in agriculture Biocentury Transgene (China) Co., Ltd. Hongzhi Cui, Hongzhi Cui cuihongzhi@biocentury.com.cn Search for more papers by this authorTao Huang, Tao Huang huangtao@biocentury.com.cn Search for more papers by this author Hongzhi Cui, Hongzhi Cui cuihongzhi@biocentury.com.cn Search for more papers by this authorTao Huang, Tao Huang huangtao@biocentury.com.cn Search for more papers by this author First published: 16 November 2006 https://doi.org/10.1002/biot.200690128AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. REFERENCES 1 Cui Hongzhi, Guo Sandui, Construction of plant expression vectors harbouring two insecticidal genes and their expression in tobacco. Journal of Agricultural Biotechnolgoy 1998, 6, (1), 7– 13 (in Chinese with English abstract). 2 Guo Sandui, Cui Hongzhi, Xia Lanqin, Wu Dongliang, Ni Wanchao, Zhang Zhenlin, Zhang Baolong and Xu Yingjun, Development of bivalent insect-resistant transgenic cotton plants. Scientia Agricultura Sinica 1999, 32, (3), 1– 7 (in Chinese with English abstract). 3 Zhang Zhenlin, Ni Wanchao, Guo Sandui, Shu Chune, Cui Hongzhi, Zhang Baolong, Xu Yingjun, Insect-resistant transgenic cotton plants transformed with pollen tube pathway. Acta Agriculturae Boreali-occidentalis Sinica 2000, 9, (2), 1– 4 (in Chinese with English abstract). 4 Guo Sandui, Cui Hongzhi, Synthesization of GFM Cry1A insecticidal gene and construction of plant expression vectors in insect-resistant transgenic cotton. Review of China Agricultural Science and Technology 2000, 2, (2), 21– 26 (in Chinese with English abstract). 5 Cui Hongzhi, Zhang Rui, Ni Wanchao and Guo Sandui. Development of Insect-resistant Transgenic Cottons. In: Proceedings of International Conference on Engineering and Technological Sciences 2000. Session 6, Technology Innovation and Sustainable Agriculture. Song jian (Eds.), New World Press, 437–438. Volume1, Issue11Special Issue: Biotech in ChinaNovember 2006Pages 1203-1204 ReferencesRelatedInformation

The Impacts of the Pollen of Insect-resistant Transgenic Cotton on Honeybees

Transgenic cotton containing a synthetic version of the insecticidal toxin gene from Bacillus thuringiensis subsp. kurstaki has been planted in China in a large scale and may have adverse impacts on honeybees. The pollens of the transgenic cotton and the non-transgenic parental cotton were collected and their impacts on worker bees were tested. Experimental results showed that the transgenic cotton pollen had no oral acute toxic effects on worker bees. No significant difference was observed in the superoxide dismutases activity and the longevity of worker bees fed with diets containing the transgenic cotton pollen or non-transgenic parental cotton pollen. The results of our experiment indicate that the transgenic cotton has no direct adverse impacts on honeybees. Further work needs to be carried out to evaluate the long-term and indirect impacts of the transgenic cotton on honeybees.