转基因植物环境安全评价策略

构建完善的转基因植物环境安全评价技术体系是保障转基因生物产业健康发展的重要组成部分。本文综述了转基因植物环境安全评价技术发展历程与趋势,归纳了转基因植物环境安全评价的思路与内容。转基因植物环境安全评价应分为潜在风险分析、风险假设验证、风险特征描述等3个步骤,并采用逐层评价模式;安全评价应贯穿转基因植物新品种研发与产业化全程,包括应用前预测、研发中筛选、推广前评价、推广后监测。此外,基于科学性和个案分析原则,本文对复合性状、非生物胁迫抗性等新型转基因植物环境安全评价策略进行了探讨。     

转基因植物的生态风险

转基因植物已在很多国家大规模商业化种植,并且取得了显著的经济效益。同时有关转基因植物潜在的生态风险已引起广泛的关注。本文从转基因植物人侵危害、对非靶标有益生物直接和间接的影响、害虫对抗虫转基因植物产生抗性、抗病毒转基因植物带来的潜在风险等方面论述了转基因植物可能潜在的生态安全性问题。     

我国转基因水稻商品化应用的潜在环境生物安全问题

转基因水稻的研发和商品化应用将为提高我国水稻的生产力提供新的机遇,并缓解我国的粮食安全问题.转基凶水稻的人规模环境释放和商品化生产可能会带来一定的环境生物安全问题,处理不好会影响转基因水稻的进一步研究和发展.通常所指的环境生物安全问题主要包括以下几个方面:(1)抗生物胁迫转基因对非靶标生物的影响及效应;(2)外源基因向非转基因作物和野生近缘种逃逸及其可能带来的生态后果;(3)转基因作物对农业生态系统、土壤微生物以及生物多样性的潜在影响;(4)抗生物胁迫转基因的长期使用导致靶标生物对转基因产生抗性等.为了安全有效和持续利用转基因生物技术及其产品,有必要对转基因水稻的环境生物安全性进行科学评价.基于风险评价的原则,本文对转基因水稻在我国商品化生产和大规模种植可能带来的环境生物安全问题进行了理性分析,希望为我国转基因水稻商品化应用的决策和生物安全评价提供科学依据.     

植物转基因的进展与禾谷类作物转基因的评估

植物转基因技术主要包括病原生物感染系统转基因和理化法直接转基因,这是近五年多来发展极为迅速的领域,我国已有许多研究报道,并有不少综述.本文即在此基础上深入介绍植物转基因的研究进展,及其在禾谷类作物上应用所面临的问题。     

安全型转基因植物培育技术研究进展

由于关系到转基因植物的产业化前景,安全型转基因植物培育越来越受到公众的关注。在植物遗传转化体系中,绝大多数选择标记基因来源于细菌,对人类健康和环境安全存在潜在风险,因此无选择标记转基因植物培育受到科研工作者的高度重视。本文综述了安全型转基因植物的培育途径,包括共转化系统、位点特异性重组系统、转座子系统、同源重组系统、不依赖于组织培养的简易转化技术及再生相关基因利用等技术,探讨了各种途径的优缺点,以期推动安全型转基因植物培育和转基因植物产业化进程。     

安全转基因植物培育技术研究进展

由于关系到转基因植物的产业化前景,安全型转基因植物培育越来越受到公众的关注。在植物遗传转化体系中,绝大多数选择标记基因来源于细菌,对人类健康和环境安全存在潜在风险,因此无选择标记转基因植物培育受到科研工作者的高度重视。本文综述了安全型转基因植物的培育途径,包括共转化系统、位点特异性重组系统、转座子系统、同源重组系统、不依赖于组织培养的简易转化技术及再生相关基因利用等技术,探讨了各种途径的优缺点,以期推动安全型转基因植物培育和转基因植物产业化进程。     

转基因植物的生态风险评价

自从１９８３年第一株转基因植物诞生以来,至今各种类型的转基因植物进入大田试验的已不计其数,近１０种转基因作物的产物已经商品化。与此同时,转基因植物向环境释放后可能带来的生态风险问题也越来越受到人们的重视。关于转基因植物的生态风险或对环境的危害,科学家提出了不同的概念和测试方法。生态毒理学的经验以及８０年代发展起来的,为作环境决策用的生态风险评价的经验可以借鉴以作转基因植物生态风险的评价。本文介绍了转基因植物对农田生态系统和自然生态系统可能带来的危害以及从基因、基因组、个体、种群以至生态系统等各级水平上危害测试的方法。对风险的判断作了详细的论述,对风险的管理也作了概略的介绍,并对生态风险评价当前发展的水平进行了讨论。     

转基因植物中外源非目的基因片段的生物安全研究进展

生物安全（ｂｉｏｓａｆｅｔｙ）是指与以人类和环境为对象的生物学研究所产生的效应相关的安全性［1］,或对生物危害的检测、评价、监测、防范和治理的科学技术体系 ① 。遗传修饰生物体（ＧＭＯ）,特别是转基因植物的安全性是生物安全的重要内容,近几年已经引起政府、社会和科学界的广泛关注。转基因植物对人体健康的负面影响的考虑要点主要包括对人体的毒性、过敏原性、营养成分的改变与抗营养因子以及抗生素抗性等。对生态环境的负面影响即生态学风险的考虑要点包括转基因植物导致杂草问题,产生新病毒或加重病害,对非目标生物的影…     

植物的遗传转化及其应用(英文)

近年来,植物遗传转化研究有了长足的发展。已经达到能够通过简单的遗传控制手段研究具有新表现型的植物,甚至达到进入商业化的程度。这些手段包括植物生物学的主要研究技术以及植物组织培养和树种改良的一些实用方法。尽管采用农瘤杆菌和鸟枪法等技术的植物遗传转化系统已经得到了广泛的应用,但是在如何开发具有能够得到控制表达的转基因高产植物方面,在如何使所得到的转基因植物远离遗传危害等方面,目前的转化系统遇到了极大的技术挑战。已经提出了各种各样的方法用于将新基因稳定地导入120多种不同植物的核基因组。本文将讨论这些遗传转化系统所需的生物学要求和实际应用方面的需求、基因转化和转基因表达的研究策略、遗传转化植物的鉴定以及转基因植物与大众的认可。本文将分为七个部分加以讨论:一、导言;二 、基因转化到细胞里的方法;三、植物遗传转化策略;四、植物遗传转化的鉴定;五、植物遗传转化的实际应用;六、转基因植物与环境;七、未来植物遗传转化的需求与发展方向。     

欧盟新型植物育种技术的研究及监管现状

近年来多种具有较大应用前景的新型植物育种技术,如寡核苷酸定点诱变、锌指核酸酶技术、同源转基因技术、RNA介导的DNA甲基化、反向育种、转基因砧木嫁接和农杆菌浸润等在欧洲发展迅速。这些新技术比常规育种技术更具特异性和针对性,可为育种家提供准确和有效的方法。文献计量学研究表明,农杆菌浸润和RNA介导的DNA甲基化等技术在欧盟研究中使用率较高;德国、英国是欧盟新型植物育种技术研究的重要国家。目前,欧盟正在讨论由这些新技术产生的植物是否属于其监管体系,尤其是2001/18/EC指令中定义的转基因生物。相关机构也纷纷发布一系列报告,对新技术产生的植物及产品的分类监管问题进行了广泛讨论。欧洲食品安全局分别对同源转基因(cisgenesis/Intragenesis)和锌指核酸酶(ZFN-3)等技术产生的植物进行风险评估,并认为Cisgenesis与常规育种技术植物的风险程度相当,Intragenesis和常规转基因技术获得的植物均可能造成新风险;ZFN-3技术比常规转基因技术具有更小的风险。     

Risk assessment strategies for transgenic plants

Advances in recombinant DNA technology have created advantages for the development of plants with high agro-economical values. Since the production of transgenic plants, some issues concerning the safe use of these plants and their products have been under debate throughout the world. In this respect, the potential risks and benefits of transgenic plants need to be evaluated objectively. Risk assessment of transgenic crops is a basic prerequisite for monitoring the possible risks that could arise upon the release and use of transgenic plants. To get a meaningful tool for decision making, risk assessment needs to be carried out in a scientific sound and transparent manner. There are specific governmental regulations in many countries for the safety assessment of genetically modified (GM) crops. Furthermore, there are some international agreements, which regulate the cultivation and commercialization of transgenic plants and their derivatives. Internationally accepted risk assessment strategies have been performed to evaluate the safe use of a large variety of GM crops. The main objectives of these regulations and risk assessment strategies are focused to protect human/animal health and the environment.     

Assessing environmental risks of transgenic plants

By the end of the 1980s, a broad consensus had developed that there were potential environmental risks of transgenic plants requiring assessment and that this assessment must be done on a case-by-case basis, taking into account the transgene, recipient organism, intended environment of release, and the frequency and scale of the intended introduction. Since 1990, there have been gradual but substantial changes in the environmental risk assessment process. In this review, we focus on changes in the assessment of risks associated with non-target species and biodiversity, gene flow, and the evolution of resistance. Non-target risk assessment now focuses on risks of transgenic plants to the intended local environment of release. Measurements of gene flow indicate that it occurs at higher rates than believed in the early 1990s, mathematical theory is beginning to clarify expectations of risks associated with gene flow, and management methods are being developed to reduce gene flow and possibly mitigate its effects. Insect pest resistance risks are now managed using a high-dose/refuge or a refuge-only strategy, and the present research focuses on monitoring for resistance and encouraging compliance to requirements. We synthesize previous models for tiering risk assessment and propose a general model for tiering. Future transgenic crops are likely to pose greater challenges for risk assessment, and meeting these challenges will be crucial in developing a scientifically coherent risk assessment framework. Scientific understanding of the factors affecting environmental risk is still nascent, and environmental scientists need to help improve environmental risk assessment.     

Genetically modified crops: success, safety assessment, and public concern

With the emergence of transgenic technologies, new ways to improve the agronomic performance of crops for food, feed, and processing applications have been devised. In addition, ability to express foreign genes using transgenic technologies has opened up options for producing large quantities of commercially important industrial or pharmaceutical products in plants. Despite this high adoption rate and future promises, there is a multitude of concerns about the impact of genetically modified (GM) crops on the environment. Potential contamination of the environment and food chains has prompted detailed consideration of how such crops and the molecules that they produce can be effectively isolated and contained. One of the reasonable steps after creating a transgenic plant is to evaluate its potential benefits and risks to the environment and these should be compared to those generated by traditional agricultural practices. The precautionary approach in risk management of GM plants may make it necessary to monitor significant wild and weed populations that might be affected by transgene escape. Effective risk assessment and monitoring mechanisms are the basic prerequisites of any legal framework to adequately address the risks and watch out for new risks. Several agencies in different countries monitor the release of GM organisms or frame guidelines for the appropriate application of recombinant organisms in agro-industries so as to assure the safe use of recombinant organisms and to achieve sound overall development. We feel that it is important to establish an internationally harmonized framework for the safe handling of recombinant DNA organisms within a few years.This is IMTECH Communication No. 038/2005.     

转基因植物的环境生物安全：转基因逃逸及其潜在生态风险的研究和评价

转基因作物的商品化生产和大规模环境释放在带来巨大利益的同时,也引起了全球对其生物安全问题的广泛关注和争议,其中转基因通过花粉介导的基因漂移逃逸到非转基因作物及其野生近缘种,进而导致的潜在环境和生态风险就是备受争议的生物安全问题之一。转基因植物的环境生物安全涉及两方面关键问题：如何科学评价转基因植物商品化种植以后带来的环境和生态影响;如何利用环境生物安全的研究成果来制定科学有效的风险监测和管理措施。对转基因逃逸及其潜在生态风险的科学评价应包括三个重要环节：（1）检测转基因的逃逸的频率;（2）检测转基因逃逸后的表达和遗传规律;（3）确定逃逸后的转基因对野生近缘种群体适合度的影响及其进化潜力,本文将围绕对转基因逃逸及其潜在环境风险的科学评价,以转基因水稻为案例来对转基因逃逸带来生态影响的研究好评价的进展进行简要介绍,并对目前依据风险评价研究成果制定的各种管理策略进行了讨论。只有提高对转基因生物环境安全研究和评价的水平,并制定有效的风险监测和管理措施,才能为我国转基因技术的发展和转基因产品的商品化应用保驾护航。     

利用决策树方法建立转基因植物环境生物安全评价诊断平台

转基因技术及其产品是解决世界粮食问题的重要途径之一, 但是包括食品和环境安全在内的转基因生物安全评价是转基因技术及其产品商品化应用的前提和保证。现有的人为生物安全评价方法存在着一定的不足, 难以应对数量日益增加和内容日趋复杂的转基因产品的安全评价需求, 因此找寻一种客观和高效的评价方法势在必行。决策树(decision tree)方法是现今广泛使用的数据挖掘和分析的决策方法之一, 通过将需要解答问题的层层分解并分别解决, 最终得到理想的决策结果, 在处理复杂问题方面具有独特的优势。本文旨在通过介绍决策树的概念、特性、种类及其构建方法, 探索将决策树方法应用于建立转基因植物环境生物安全评价诊断平台的可行性, 并分析构建的诊断平台在高效、准确和客观地进行转基因植物环境生物安全评价, 以及对新一代转基因产品环境安全性的预测和普及环境安全知识等方面的优势, 为进一步推动转基因技术的发展和转基因产品的安全利用奠定基础。     

转基因植物根系分泌物对土壤微生态的影响

随着转基因植物商品化进程的加快,对其进行生态风险性评价日益引起学者的重视。诸如转基因逃逸到其它亲缘物种中、产生超级杂草和病毒、昆虫产生耐受性及生物多样性遭受破坏等问题已在部分转基因作物中显现。本文综述了转基因植物中根系分泌物对土壤微生态的影响。     

A Comparative Risk Assessment of Genetically Engineered,Mutagenic, and Conventional Wheat Production Systems

Wheat (Triticum aestivum L.) varieties produced using modern biotechnologies, such as genetic engineering and mutagenic techniques, have lagged behind other crop species, but are now being developed and, in the case of mutagenic wheat, commercially grown around the world. Because these wheat varieties have emerged recently, there is a unique opportunity to assess comparatively the potential environmental risks (human health, ecological, and livestock risks) associated with genetically engineered, mutagenic, and conventional wheat production systems. Replacement of traditional herbicides with glyphosate in a glyphosate-tolerant (genetically engineered) wheat system or imazamox in an imidazolinone-tolerant (mutagenic) wheat system may alter environmental risks associated with weed management. Additionally, because both systems rely on plants that express novel proteins, the proteins and plants themselves may impose risks. The purpose of our study was to examine comparatively the multiple aspects of risk associated with different wheat production systems in the US and Canada using the risk assessment paradigm. Specifically, we used tier 1 quantitative and qualitative risk assessment methods to compare specific environmental risks associated with the different wheat production systems. Both glyphosate and imazamox present lower human health and ecological risks than many other herbicides associated with conventional wheat production systems evaluated in this study. The differences in risks were most pronounced when comparing glyphosate and imazamox to herbicides currently with substantial market share. Current weight-of-evidence suggests that the transgenic CP4 EPSPS protein present in glyphosate-tolerant wheat poses negligible risk to humans, livestock, and wildlife. Risk for mutated AHAS protein in imidazolinone-tolerant wheat most likely would be low, but there are not sufficient effect and exposure data to adequately characterize risk. Environmental risks for herbicides were more amenable to quantitative assessments than for the transgenic CP4 EPSPS protein and the mutated AHAS protein.     

Ecological Risk Assessment and Regulation for Genetically-Modified Ornamental Plants

Classic plant breeding has increased the beauty and utility of ornamental plants, but biotechnology can offer completely new traits for plants used in homes and gardens. The creation of blue petal color in carnations and roses are examples where biotechnology has created novelty that conventional hybridization cannot match. However, all innovations have benefits and risks, and future commercialization of transgenic ornamental plants raises complex questions about potential negative impacts to managed landscapes and natural ecosystems. Predictive ecological risk assessment is a process that uses current knowledge to estimate future environmental harms or benefits arising from direct or indirect exposure to a genetically-modified (GM) plant, its genes, or gene products. This article considers GM ornamental plants in the context of current ecological risk assessment principles, research results, and current regulatory frameworks. The use of ecological risk assessment by government agencies to support decision-making is reviewed in the context of ornamental plants. Government risk assessments have usually emphasized the potential for pollen-mediated gene flow, weediness in managed areas, invasion of natural areas, and direct harm to nontarget organisms. Some of the major challenges for predictive risk assessment include characterizing gene flow over time and space, plant fitness in changing environments, and impacts to nontarget organisms, communities and ecosystems. The lack of baseline information about the ecology and biodiversity of urban areas, gardens, and natural ecosystems limits the ability to predict potential hazards, identify exposure pathways, and design hypothesis-driven research. The legacy of introduced ornamental plants as invasive species generates special concern about future invasions, especially for GM plants that exhibit increased stress tolerance or adaptability. While ecological risk assessments are a valuable tool and have helped harmonize regulation of GM plants, they do not define the acceptable level of risk or uncertainty. That responsibility belongs to regulators, stakeholders and citizens.     

Comparative Risk Assessment Methods and Their Applicability to Dredged Material Management Decision-Making

This article reviews the status of comparative risk assessment within the context of environmental decision-making; evaluates its potential application as a decision-making framework for selecting alternative technologies for dredged material management; and makes recommendations for implementing such a framework. One of the most important points from this review for decision-making is that comparative risk assessment, however conducted, is an inherently subjective, value-laden process. There is some objection to this lack of total scientific objectivity (“hard version” of comparative risk assessment). However, the “hard versions” provide little help in suggesting a method that surmounts the psychology of choice in decision-making schemes. The application of comparative risk assessment in the decision-making process at dredged material management facilities will have an element of value and professional judgment in the process. The literature suggests that the best way to incorporate this subjectivity and still maintain a defensible comparative framework is to develop a method that is logically consistent and allows for uncertainty by comparing risks on the basis of more than one set of criteria, more than one set of categories, and more than one set of experts. It should incorporate a probabilistic approach where necessary and possible, based on management goals.