转基因作物的安全性及其对策

随着转基因作物的商业化,转基因作物的安全性问题在世界范围内倍受关注.通过对转基因作物的发展概况、优点和生物安全性进行简要综述,分析了转基因作物安全性产生的机理,并提出了相应的对策.     

复合性状转基因植物安全性评价的研究进展

随着转基因技术的不断发展,转基因作物实现了产业化。目前,单性状的转基因作物无法满足农业发展的需求,而复合性状转基因作物拓宽了转基因作物的功能,提高了资源的利用率,满足了农民多元化需求,具有广阔的应用前景,是转基因植物发展的新方向。由于转基因技术有一定的风险,因此对转基因作物的安全性监管较为重要,对于复合性状转基因作物,不同国家的安全性评价制度却不尽相同。综述了不同国家对复合性状转基因作物的安全性评价体制,旨为我国复合性状作物提供监管依据。     

转基因作物的生态安全性问题及其对策

随着转基因作物商业化进程的加快,转基因作物的安全性引起了人们越来越多的关注,主要就转基因作物生态安全性问题以及产生的原因进行综述,并提出我国现阶段应采取的对策。     

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。     

转基因抗虫作物对捕食性瓢虫的安全性研究进展

转基因抗虫作物的商业化种植带来了显著的经济、生态和社会效益,对转基因抗虫作物的安全性评价也一直是国内外学者研究的热点。对生物非靶标效应的研究是转基因抗虫作物安全性评价的重要组成部分,农田天敌类生物是其中的重点内容之一。瓢虫是农田生态系统重要的捕食性天敌,评价其在转基因抗虫作物田间是否能通过捕食猎物或取食花粉而接触到杀虫蛋白并富集于体内,进而对自身产生一定的非靶标效应,这对捕食性瓢虫的安全性研究具有重要的意义。本文从捕食性天敌瓢虫的生命表参数、行为功能参数、田间群落参数及体内微环境指标等方面综述了转基因抗虫作物对瓢虫的安全性研究进展,并对后期转基因抗虫作物对田间捕食性天敌的研究方向提出了建议,以期为转基因抗虫作物的环境安全性研究提供理论指导和为进一步完善转基因抗虫作物对瓢虫安全性评价的技术体系提供系统的数据资料。     

转基因作物和转基因技术的发展与未来

转基因作物的安全性问题在20世纪末引起全球性的争论,一些人反对转基因植物和转基因技术.本文概述了转基因植物产生的必然性、应用现状、发展趋势、引起争论的主要原因以及必须建立的安全性保障,阐明对转基因作物和技术应采取的科学态度.     

中国转基因作物风险评估技术研究进展

现代生物技术的发展为利用外源基因培育优良作物品种提供了新的途径,目前国内外已培育出多个高抗害虫的转基因作物。但是,人们对转基因作物潜在的风险尚存在疑问,这是目前转基因作物是否能进一步获准商品化生产的一个重要原因。综述了中国转基因作物研究和转基因产品安全性检测技术取得的主要进展,对我国转基因作物的研究前景进行了展望,并对将来的工作提出了几点建议。     

国内外转基因作物产业化的比较

当前,全球转基因作物研发和产业化迅猛发展, 创造了巨大的经济、社会和生态效益。转基因作物产业化发展的快慢, 是关系到我国农业可持续发展和提高农产品国际竞争力的重大问题。就国内外转基因作物的产业化进行了优劣势比较, 并从影响转基因作物产业化的技术瓶颈和安全性监管两方面进行了探讨。     

转基因作物对土壤无脊椎动物的影响

随着生物技术的快速发展,越来越多的转基因作物被引入农业生态系统,继而引发转基因作物对土壤生态系统带来影响的担忧。土壤无脊椎动物作为食物链中的分解者,是土壤生态系统的重要组成成分,其数量和多样性直接与土壤的健康和质量相关。土壤无脊椎动物作为土壤质量的重要指标,已成为转基因作物环境安全性评价的重要内容之一。本文在概述近些年国内外关于转基因作物外源表达产物在土壤中的残留动态的检测结果的基础上,综述关于棉花、玉米、水稻、油菜等转基因作物对线虫、跳虫、螨类和蚯蚓等代表性土壤无脊椎动物影响的最新研究进展。总体来说,转基因作物对土壤无脊椎动物的群落多样性没有明显不利影响,但个别对环境变化特别敏感的类群,在数量或组成上有所不同。由于调查方法和作物种类、土壤类型等因素的不统一,不同的研究结果无法进行比较,因此,建议尽快建立转基因作物对土壤无脊椎动物影响的评价方法和标准,以便为转基因作物的环境影响评价提供客观可靠的评价结果,推动我国的转基因作物研发和商业化推广,同时最大限度地降低转基因作物对环境的不利影响。     

国内外转基因作物产业化的比较

当前,全球转基因作物研发和产业化迅猛发展, 创造了巨大的经济、社会和生态效益。转基因作物产业化发展的快慢, 是关系到我国农业可持续发展和提高农产品国际竞争力的重大问题。就国内外转基因作物的产业化进行了优劣势比较, 并从影响转基因作物产业化的技术瓶颈和安全性监管两方面进行了探讨。     

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。     

Transgenic plants and biosafety: science, misconceptions and public perceptions

One usually thinks of plant biology as a non-controversial topic, but the concerns raised over the biosafety of genetically modified (GM) plants have reached disproportionate levels relative to the actual risks. While the technology of changing the genome of plants has been gradually refined and increasingly implemented, the commercialization of GM crops has exploded. Today's commercialized transgenic plants have been produced using Agrobacterium tumefaciens-mediated transformation or gene gun-mediated transformation. Recently, incremental improvements of biotechnologies, such as the use of green fluorescent protein (GFP) as a selectable marker, have been developed. Non-transformation genetic modification technologies such as chimeraplasty will be increasingly used to more precisely modify germplasm. In spite of the increasing knowledge about genetic modification of plants, concerns over ecological and food biosafety have escalated beyond scientific rationality. While several risks associated with GM crops and foods have been identified, the popular press, spurred by colorful protest groups, has left the general public with a sense of imminent danger. Reviewed here are the risks that are currently under research. Ecological biosafety research has identified potential risks associated with certain crop/transgene combinations, such as intra- and interspecific transgene flow, persistence and the consequences of transgenes in unintended hosts. Resistance management strategies for insect resistance transgenes and non-target effects of these genes have also been studied. Food biosafety research has focused on transgenic product toxicity and allergenicity. However, an estimated 3.5 x 10(12) transgenic plants have been grown in the U.S. in the past 12 years, with over two trillion being grown in 1999 and 2000 alone. These large numbers and the absence of any negative reports of compromised biosafety indicate that genetic modification by biotechnology poses no immediate or significant risks and that resulting food products from GM crops are as safe as foods from conventional varieties. We are increasingly convinced that scientists have a duty to conduct objective research and to effectively communicate the results--especially those pertaining to the relative risks and potential benefits--to scientists first and then to the public. All stakeholders in the technology need more effective dialogues to better understand risks and benefits of adopting or not adopting agricultural biotechnologies.     

我国转基因作物育种发展回顾与思考

文章综述了近30年来我国转基因作物育种发展历程和基本经验,并以实例说明我国已初步建成了世界上为数不多的转基因育种创新和产业开发体系,包括基因发掘、遗传转化、良种培育、产业开发,应用推广以及安全评价等关键环节;棉花、水稻、玉米等作物转基因研究创新能力得到进一步提升,初步形成了自己的研究特色和比较优势。本文对转基因作物育种当前存在的问题与面对的挑战进行了分析,提出了推进重大研究成果产业化、加快重大专项实施和自主创新、加强转基因科学传播等三点建议。     

Calling the tunes on transgenic crops: the case for regulatory harmony

Genetically modified (GM) crops are now grown commercially in 23 countries, with another 29 granting approval for import and release into the environment. Despite the socio-economic and environmental benefits of the technology, further development is being hampered by differences in national regulatory frameworks relating to research, biosafety, and to the trade and use of GM crops. The biosafety regulations in different countries are based on five main international instruments that influence the development of national biosafety systems in terms of field trial permit requirements, risk assessment criteria, labeling, traceability, transparency, public awareness, post-monitoring and import regulations. The global harmonization of data collection, testing procedures and information exchange would help to remove artificial trade barriers, expedite the adoption of GM crops, foster technology transfer and protect developing countries from exploitation, instilling confidence and bringing the benefits of GM products to the consumer.     

Intein-mediated Cre protein assembly for transgene excision in hybrid progeny of transgenic <Emphasis Type="Italic">Arabidopsis</Emphasis>

Key message

An approach for restoring recombination activity of complementation split-Cre was developed to excise the transgene in hybrid progeny of GM crops.

Abstract

Growing concerns about the biosafety of genetically modified (GM) crops has currently become a limited factor affecting the public acceptance. Several approaches have been developed to generate selectable-marker-gene-free GM crops. However, no strategy was reported to be broadly applicable to hybrid crops. Previous studies have demonstrated that complementation split-Cre recombinase restored recombination activity in transgenic plants. In this study, we found that split-Cre mediated by split-intein Synechocystis sp. DnaE had high recombination efficiency when Cre recombinase was split at Asp232/Asp233 (866 bp). Furthermore, we constructed two plant expression vectors, pCA-NCre-In and pCA-Ic-CCre, containing NCre866-In and Ic-CCre866 fragments, respectively. After transformation, parent lines of transgenic Arabidopsis with one single copy were generated and used for hybridization. The results of GUS staining demonstrated that the recombination activity of split-Cre could be reassembled in these hybrid progeny of transgenic plants through hybridization and the foreign genes flanked by two loxP sites were efficiently excised. Our strategy may provide an effective approach for generating the next generation of GM hybrid crops without biosafety concerns.

     

Recent advances in development of marker-free transgenic plants: Regulation and biosafety concern

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 crop plants. From the biosafety authority and consumer viewpoints, the presence of selectable marker genes in released transgenic crops may be transferred to weeds or pathogenic microorganisms in the gastrointestinal tract or soil, making them resistant to treatment with herbicides or antibiotics, respectively. Sexual crossing also raises the problem of transgene expression because redundancy of transgenes in the genome may trigger homology-dependent gene silencing. The future potential of transgenic technologies for crop improvement depends greatly on our abilities to engineer stable expression of multiple transgenic traits in a predictable fashion and to prevent the transfer of undesirable transgenic material to non-transgenic crops and related species. Therefore, it is now essential to develop an efficient marker-free transgenic system. These considerations underline the development of various approaches designed to facilitate timely elimination of transgenes when their function is no longer needed. Due to the limiting number of available selectable marker genes, in future the stacking of transgenes will be increasingly desirable. The production of marker-free transgenic plants is now a critical requisite for their commercial deployment and also for engineering multiple and complex trait. Here we describe the current technologies to eliminate the selectable marker genes (SMG) in order to develop marker-free transgenic plants and also discuss the regulation and biosafety concern of genetically modified (GM) crops.     

Biosafety management and commercial use of genetically modified crops in China

As a developing country with relatively limited arable land, China is making great efforts for development and use of genetically modified (GM) crops to boost agricultural productivity. Many GM crop varieties have been developed in China in recent years; in particular, China is playing a leading role in development of insect-resistant GM rice lines. To ensure the safe use of GM crops, biosafety risk assessments are required as an important part of the regulatory oversight of such products. With over 20 years of nationwide promotion of agricultural biotechnology, a relatively well-developed regulatory system for risk assessment and management of GM plants has been developed that establishes a firm basis for safe use of GM crops. So far, a total of seven GM crops involving ten events have been approved for commercial planting, and 5 GM crops with a total of 37 events have been approved for import as processing material in China. However, currently only insect-resistant Bt cotton and disease-resistant papaya have been commercially planted on a large scale. The planting of Bt cotton and disease-resistant papaya have provided efficient protection against cotton bollworms and Papaya ringspot virus (PRSV), respectively. As a consequence, chemical application to these crops has been significantly reduced, enhancing farm income while reducing human and non-target organism exposure to toxic chemicals. This article provides useful information for the colleagues, in particular for them whose mother tongue is not Chinese, to clearly understand the biosafety regulation and commercial use of genetically modified crops in China.     

Surveying of pollen-mediated crop-to-crop gene flow from a wheat field trial as a biosafety measure

Outcrosses from genetically modified (GM) to conventional crops by pollen-mediated gene flow (PMGF) are a concern when growing GM crops close to non-GM fields. This also applies to the experimental releases of GM plants in field trials. Therefore, biosafety measures such as isolation distances and surveying of PMGF are required by the regulatory authorities in Switzerland. For two and three years, respectively, we monitored crop-to-crop PMGF from GM wheat field trials in two locations in Switzerland. The pollen donors were two GM spring wheat lines with enhanced fungal resistance and a herbicide tolerance as a selection marker. Seeds from the experimental plots were sampled to test the detection method for outcrosses. Two outcrosses were found adjacent to a transgenic plot within the experimental area. For the survey of PMGF, pollen receptor plots of the conventional wheat variety Frisal used for transformation were planted in the border crop and around the experimental field up to a distance of 200 m. Although the environmental conditions were favorable and the donor and receptor plots flowered at the same time, only three outcrosses were found in approximately 185,000 tested seedlings from seeds collected outside the experimental area. All three hybrids were found in the border crop surrounding the experimental area, but none outside the field. We conclude that a pollen barrier (border crop) and an additional isolation distance of 5 m is a sufficient measure to reduce PMGF from a GM wheat field trial to cleistogamous varieties in commercial fields below a level that can be detected.