转基因抗虫作物对非靶标昆虫的影响

转基因抗虫作物自 1996年被批准商业化种植以来 ,它的抗虫性和经济效益已得到了普遍肯定 ,同时 ,转基因抗虫作物对非靶标生物的影响 ,如转基因抗虫作物的长期种植 ,是否会导致次要害虫上升为主要害虫 ,是否会影响有益昆虫 ,包括重要经济昆虫、捕食性和寄生性天敌以及重要蝶类的种类及种群数量 ,已成为转基因抗虫作物生态风险评估的重要内容。一些研究结果表明 ,转基因抗虫作物在对靶标害虫有效控制的同时 ,一些对杀虫蛋白不敏感的非靶标害虫有加重危害的趋势 ,由于种植转基因抗虫作物 ,减少了化学农药的使用 ,客观上也使非靶标害虫种群数量上升 ,这对转基因抗虫作物害虫综合治理提出了新的要求。靶标害虫数量的减少直接影响了害虫天敌种群数量 ,靶标害虫取食转基因抗虫作物后发育迟缓 ,也间接影响了天敌昆虫的生长发育 ,转基因抗虫作物的花粉或花蜜是一些重要经济昆虫如蜜蜂、熊蜂和一些寄生蜂 ,甚至捕食性天敌的食物来源 ,或花粉飘落到一些鳞翅目昆虫如家蚕或重要蝶类昆虫的寄主植物上 ,直接或间接对这些昆虫造成一定影响。目前大多数研究表明转基因抗虫作物对非靶标昆虫 ,特别是对有益昆虫没有明显的不利影响 ,也有研究报道认为对某些有益昆虫有一定的不良影响。这为深入开展转基因抗虫作物的生态安全     

Development and deployment of transgenic plants: Biosafety considerations

Summary Recombinant DNA technology has great potential to enhance and extend the advantages of conventional plant breeding, and increase the production and productivity of crops to meet the increasing demand for food and food products in the future. Judicious application of this technology provides opportunities for alleviating some of the major constraints to crop productivity under subsistence farming conditions in the developing countries. Considerable progress has been made in developing strategies for the production and deployment of transgenic crops. However, biosafety concerns have been raised regarding the deployment and release of genetically engineered plants. This debate has divided the farming and consumer communities over acceptability of genetically modified foods. There is a need for a thorough investigation regarding the fate of transgenic plants in the environment, and their interaction with wild relatives and non-target organisms. The production and release of transgenic plants should be based on experience and sound scientific reasoning. The regulatory requirements for deployment of transgenic crops should be streamlined and harmonized, in order to achieve sustainable food production, poverty reduction, and environmental protection in resource-poor countries in the semi-arid tropics.     

Advancing environmental risk assessment for transgenic biofeedstock crops

Transgenic modification of plants is a key enabling technology for developing sustainable biofeedstocks for biofuels production. Regulatory decisions and the wider acceptance and development of transgenic biofeedstock crops are considered from the context of science-based risk assessment. The risk assessment paradigm for transgenic biofeedstock crops is fundamentally no different from that of current generation transgenic crops, except that the focus of the assessment must consider the unique attributes of a given biofeedstock crop and its environmental release. For currently envisioned biofeedstock crops, particular emphasis in risk assessment will be given to characterization of altered metabolic profiles and their implications relative to non-target environmental effects and food safety; weediness and invasiveness when plants are modified for abiotic stress tolerance or are domesticated; and aggregate risk when plants are platforms for multi-product production. Robust risk assessments for transgenic biofeedstock crops are case-specific, initiated through problem formulation, and use tiered approaches for risk characterization.     

生命伦理学视野下的转基因作物产业化问题研究

转基因作物的产业化作为当前生命伦理学的重要问题之一日益受到我国学术界、政府和广大公众的关注。转基因作物产业化不仅关涉到我国13亿人的吃饭问题,也与我国公众的身心健康、基本权利密切相关。转基因作物产业化的生命伦理意蕴主要体现在：转基因作物产业化的基础是确保公众健康与生命安全,关键是尊重公众权利,核心是促进社会公正。     

转基因作物的食用与环境安全性问题及其对策

自转基因技术研发和商业化生产以来,针对转基因作物的食用安全性和环境安全性问题一直是公众争论的焦点。面对全球粮食安全形势的严峻压力,如何使公众对转基因技术及其产品的客观性保持一种科学性的认识,是摆在各国(特别是发展中国家)政府和科学家面前不可忽视的课题。本文从食品和环境两个方面简要介绍了转基因作物的安全性问题,旨在还原转基因技术的科学真实性,并简要提出转基因作物的安全性对策。     

基因工程植物的安全性问题

转基因植物的研究进展很迅速,但基因工程植物是否安全一直争论不休,主要表现在转基因食品的安全性及生态安全性问题上.转基因食品的安全性涉及这些食品的过敏性、毒性以及抗生素标记基因的安全性几个方面.转基因植物的生态安全性包括基因漂流、是否能诱发昆虫产生Bt抗性和对生物多样性的影响等.本文针对这些问题,对转基因植物潜在危害以及国际上现有的评价作简要综述.     

转基因耐除草剂大豆的食用安全评价研究进展

转基因大豆是目前种植最广泛的转基因作物之一,其中具有耐除草剂特性的转基因大豆占比最高。公众对转基因食品一直争议不断,因此,其批准商业化种植前的食用安全性评价显得尤为重要。已有研究显示,转基因耐除草剂大豆已经商业化种植了二十多年,迄今为止还没有观察到任何不良反应。目前已经批准的转基因耐除草剂大豆均进行了严格的毒理学评价、过敏性评价和营养学评价,经过严格评价后上市的转基因大豆可以放心食用。综述了转基因耐除草剂大豆的主要类型,分析了可能存在的安全性问题,对转基因耐除草剂大豆的食用安全性评价方法进行了总结,以期为后续相关转基因食品安全性评价工作的开展提供借鉴。     

转基因抗虫水稻对生物多样性的影响

水稻是我国最重要的粮食作物,然而虫害造成的产量损失每年高达一千万吨以上。研究表明,转基因抗虫水稻对二化螟、三化螟和稻纵卷叶螟等水稻主要鳞翅目害虫具有高抗性,可以大幅度减少化学杀虫剂的使用。在不使用农药的情况下,在抗虫转基因水稻田中的害虫密度大幅度减少的同时,可以显著地增加中性昆虫及捕食性天敌数量和种类,显示出稻田生态系统和生物多样性的向良性发展的趋势。转基因水稻花粉向非转基因水稻品种的基因飘流实验表明,随着栽种距离的增大而显著减小,到间隔6.2 m时基因飘流频率已低于0.01%。转基因抗虫水稻的应用,对于保障我国粮食安全,保持农业可持续发展,保护生物多样性和生态环境尤其是在大幅度减少农药使用量方面具有重要意义。文章综述了转基因抗虫水稻研制进展及其对生物多样性的影响,并对农作物害虫防治的未来研究方向和发展趋势进行展望,以期为转基因抗虫水稻更好的应用提供借鉴。     

The Development of Transgenic Crops to Improve Human Health by Advanced Utilization of Seed Storage Proteins

Seed storage proteins are a major component of mature seeds. They are utilized as protein sources in foods. We designed seed storage proteins containing bioactive peptides based on their three-dimensional structures. Furthermore, to create crops with enhanced food qualities, we developed transgenic crops producing seed storage proteins with bioactive peptides. This strategy promises to prevent lifestyle-related diseases by simple daily food consumption. In this review, we discuss a strategy to develop transgenic crops to improve human health by advanced utilization of seed storage proteins.     

Safe composition levels of transgenic crops assessed via a clinical medicine model

Substantial equivalence has become established as a foundation concept in the safety evaluation of transgenic crops. In the case of a food and feed crop, no single variety is considered the standard for safety or nutrition, so the substantial equivalence of transgenic crops is investigated relative to the array of commercial crop varieties with a history of safe consumption. Although used extensively in clinical medicine to compare new generic drugs with brand-name drugs, equivalence limits are shown to be a poor model for comparing transgenic crops with an array of reference crop varieties. We suggest an alternate model, also analogous to that used in clinical medicine, where reference intervals are constructed for a healthy heterogeneous population. Specifically, we advocate the use of distribution-free tolerance intervals calculated across a large amount of publicly available compositional data such as is found in the International Life Sciences Institute Crop Composition Database.     

The development of transgenic crops to improve human health by advanced utilization of seed storage proteins

Seed storage proteins are a major component of mature seeds. They are utilized as protein sources in foods. We designed seed storage proteins containing bioactive peptides based on their three-dimensional structures. Furthermore, to create crops with enhanced food qualities, we developed transgenic crops producing seed storage proteins with bioactive peptides. This strategy promises to prevent lifestyle-related diseases by simple daily food consumption. In this review, we discuss a strategy to develop transgenic crops to improve human health by advanced utilization of seed storage proteins.     

The impact of the EU regulatory constraint of transgenic crops on farm income

World population and the need for nutritious food continue to grow. For 14 years farmers from a range of countries across the globe have been accessing transgenic technologies either to reduce crop production costs, increase yield and/or to exploit a range of rotational benefits. In 2009 134 Mha of transgenic crops was grown. The arable area of the EU 27 is approximately 102 Mha; however, only about 0.1 Mha of transgenic crops, mainly maize in Spain, is grown in the EU. This is in part due to limited approvals before the establishment of a moratorium on the cultivation of transgenic crops. In this paper we estimate the revenue foregone by EU farmers, based on the potential hectarages of IR and HT transgenic crops that have been economically successful elsewhere if they were to be grown in areas of the EU where farmers could expect an overall financial benefit. This benefit would accrue primarily from reduced input costs. We estimate that if the areas of transgenic maize, cotton, soya, oil seed rape and sugar beet were to be grown where there is agronomic need or benefit then farmer margins would increase by between €443 and €929 M/year. It is noted that this margin of revenue foregone is likely to increase if the current level of approval and growth remains low, as new transgenic events come to market and are rapidly taken up by farmers in other parts of the world.     

Metabolic engineering of carotenoid accumulation by creating a metabolic sink

Carotenoids are highly beneficial for human nutrition and health because they provide essential nutrients and important antioxidants in our diets. However, many food crops, especially the major staple crops contain only trace to low amounts of carotenoids. Although significant progress has been made in developing food crops rich in carotenoids by altering the expression of carotenoid biosynthetic genes, in many cases it has proved to be difficult to reach the desired levels of carotenoid enrichment. The recent identification and characterization of a novel gene mutation in cauliflower reveals that creating a metabolic sink to sequester carotenoids is an important mechanism to control carotenoid accumulation in plants. The successful demonstration of increased carotenoid accumulation in association with the formation of sink structures in transgenic crops offers a new and alternative approach to increase carotenoid content. Manipulation of the formation of metabolic sink along with the catalytic activity of the pathway may represent a promising strategy for maximally improving the nutritional quality of food crops.     

bar基因、PAT蛋白和草丁膦的特性与安全性

在转基因技术得到认同并且给全球带来了巨大的经济和社会价值的同时,也引起了人们对其安全性的关注.目前在转基因作物中抗除草剂作物种植面积最大.本文对除草剂草丁膦及其抗性基因之一--bar基因及其产物PAT蛋白的一些特性和安全性作了阐述.bar基因及筛选剂草丁膦在植物基因工程中发挥着重要作用.bar基因无多效性,与食物中的DNA一样安全.PAT蛋白对小鼠无直接毒性,与已知毒素和过敏原无同源性、无糖基化位点,其热稳定性和消化稳定性无食物过敏原和毒素的特性,对人体和动物安全无毒性.草丁膦是一种生物除草剂,在土壤中易被快速分解,作物收获时未检出残留,对哺乳动物无毒性作用.     

An oligonucleotide array to detect genetically modified events in potato

For rapid and simultaneous detection of transgenic elements in genetically modified (GM) food crops, we explored DNA array technology. Forty-four oligonucleotide 23-to 31-mers were selected to use in an array on the basis of melting temperature and sequence specificity. Selected oligonucleotides consisted of DNA fragments corresponding to structural and regulatory elements and selectable markers used in developing transgenic crops, such as potato. Other oligonucleotides represented endogenous genes from potato to serve as positive controls and from heterologous crops, such as soybean and canola, to serve as negative controls. Amino-terminated oligonucleotides were hand-spotted on activated nylon membrane with a commercial spotting device. Target DNA was isolated from foliage of transgenic and nontransgenic crops, including potato, and labeled with digoxigenin-dUTP by random priming following restriction digestion to reduce DNA fragment size. Hybridization signals were visualized by an alkaline phosphatase anti-DIG-Fab conjugate and the chemiluminescent substrate, CDP-star. We detected the presence or absence of transgenic elements in transgenic and nontransgenic potato samples. Preliminary studies demonstrated that more specific and sensitive hybridization signals were generated from an oligonucleotide probe array than from a PCR product array. We anticipate that oligonucleotide probe arrays will be useful for regulatory monitoring of transgenic events.     

转基因作物生物安全:科学证据

通过对美国Web of Science数据平台的全部转基因作物生物安全SCI论文的检索,研究了有关转基因作物生物安全的科学证据。得出科学家比消费者更关心转基因技术的安全性;批准商业化生产的转基因技术经过了有史以来最为严格的生物学安全检验与检测,并建立了有史以来最为严格的监管体系;在所发表的全部9333篇转基因生物安全论文中,90%以上的论文证明转基因技术的安全性与传统非转基因作物无显著差异;而对于所有得出转基因食品不安全结论的论文的追踪研究发现,其研究结论被证明是在错误的研究材料或方法条件下得出的。     

Using Metabolomics To Estimate Unintended Effects in Transgenic Crop Plants: Problems, Promises, and Opportunities

Transgenic crops are widespread in some countries and sectors of the agro-economy, but are also highly contentious. Proponents of transgenic crop improvement often cite the “substantial equivalence” of transgenic crops to the their nontransgenic parents and sibling varieties. Opponents of transgenic crop improvement dismiss the substantial equivalence standard as being without statistical basis and emphasize the possible unintended effects to food quality and composition due to genetic transformation. Systems biology approaches should help consumers, regulators, and other stakeholders make better decisions regarding transgenic crop improvement by characterizing the composition of conventional and transgenically improved crop species and products. In particular, metabolomic profiling via mass spectrometry and nuclear magnetic resonance can make broad and deep assessments of food quality and content. The metabolome observed in a transgenic variety can then be assessed relative to the consumer and regulator accepted phenotypic range observed among conventional varieties. I briefly discuss both targeted (closed architecture) and nontargeted (open architecture) metabolomics with respect to the transgenic crop debate and highlight several challenges to the field. While most experimental examples come from tomato (Solanum lycoperiscum), analytical methods from all of systems biology are discussed.     

我国抗虫转基因杨树生态安全性研究进展

转基因树木与农作物相比, 人们更关注其长时间种植可能导致转基因扩散到周围野生近缘种。由于生长周期长, 转基因树木会增加转基因不稳定性, 对非靶标生物的影响, 靶标害虫对转基因植物产生抗性, 增加树木入侵性(杂草化), 以及由于基因漂移或基因逃逸对环境产生的负面影响或新的环境风险。过去十几年, 针对我国抗食叶害虫的两个商业化转Bt基因欧洲黑杨(Populus nigra)和转双抗虫基因741杨[P. alba× (P. davidiana + P. simonii) × P. tomentosa], 已开展了有关生态安全性方面的多项研究。本文围绕抗虫转基因树木生态安全性研究进展进行了综述。抗虫转基因杨树对节肢动物种群和群落结构产生了一定影响, 使昆虫的多样性提高, 但对土壤微生物区系未见明显影响。转基因欧洲黑杨通过花粉和种子发生的基因漂移几率很低。转基因杨树通过内生菌发生的水平转移可能会对环境造成的潜在危险也进行了评价。文章最后指出对抗虫转基因杨树农林复合生态系统开展生物安全研究的必要性。     

Could Bt transgenic crops have nutritionally favourable effects on resistant insects?

We present an idea that larvae of some Bacillus thuringiensis (Bt ) resistant populations of the diamondback moth, Plutella xylostella (L.), may be able to use Cry1Ac toxin derived from Bt as a supplementary food protein. Bt transgenic crops could therefore have unanticipated nutritionally favourable effects, increasing the fitness of resistant populations. This idea is discussed in the context of the evolution of resistance to Bt transgenic crops.     

Allergenicity assessment of genetically modified crops--what makes sense?

GM crops have great potential to improve food quality, increase harvest yields and decrease dependency on certain chemical pesticides. Before entering the market their safety needs to be scrutinized. This includes a detailed analysis of allergenic risks, as the safety of allergic consumers has high priority. However, not all tests currently being applied to assessing allergenicity have a sound scientific basis. Recent events with transgenic crops reveal the fallacy of applying such tests to GM crops.