Genetically engineered trees for plantation forests: key considerations for environmental risk assessment

Forests are vital to the world's ecological, social, cultural and economic well‐being yet sustainable provision of goods and services from forests is increasingly challenged by pressures such as growing demand for wood and other forest products, land conversion and degradation, and climate change. Intensively managed, highly productive forestry incorporating the most advanced methods for tree breeding, including the application of genetic engineering (GE), has tremendous potential for producing more wood on less land. However, the deployment of GE trees in plantation forests is a controversial topic and concerns have been particularly expressed about potential harms to the environment. This paper, prepared by an international group of experts in silviculture, forest tree breeding, forest biotechnology and environmental risk assessment (ERA) that met in April 2012, examines how the ERA paradigm used for GE crop plants may be applied to GE trees for use in plantation forests. It emphasizes the importance of differentiating between ERA for confined field trials of GE trees, and ERA for unconfined or commercial‐scale releases. In the case of the latter, particular attention is paid to characteristics of forest trees that distinguish them from shorter‐lived plant species, the temporal and spatial scale of forests, and the biodiversity of the plantation forest as a receiving environment.     

Recommendations for the design of laboratory studies on non-target arthropods for risk assessment of genetically engineered plants

This paper provides recommendations on experimental design for early-tier laboratory studies used in risk assessments to evaluate potential adverse impacts of arthropod-resistant genetically engineered (GE) plants on non-target arthropods (NTAs). While we rely heavily on the currently used proteins from Bacillus thuringiensis (Bt) in this discussion, the concepts apply to other arthropod-active proteins. A risk may exist if the newly acquired trait of the GE plant has adverse effects on NTAs when they are exposed to the arthropod-active protein. Typically, the risk assessment follows a tiered approach that starts with laboratory studies under worst-case exposure conditions; such studies have a high ability to detect adverse effects on non-target species. Clear guidance on how such data are produced in laboratory studies assists the product developers and risk assessors. The studies should be reproducible and test clearly defined risk hypotheses. These properties contribute to the robustness of, and confidence in, environmental risk assessments for GE plants. Data from NTA studies, collected during the analysis phase of an environmental risk assessment, are critical to the outcome of the assessment and ultimately the decision taken by regulatory authorities on the release of a GE plant. Confidence in the results of early-tier laboratory studies is a precondition for the acceptance of data across regulatory jurisdictions and should encourage agencies to share useful information and thus avoid redundant testing.     

Non-coding RNAs in Crop Genetic Modification: Considerations and Predictable Environmental Risk Assessments (ERA)

Of late non-coding RNAs (ncRNAs)-mediated gene silencing is an influential tool deliberately deployed to negatively regulate the expression of targeted genes. In addition to the widely employed small interfering RNA (siRNA)-mediated gene silencing approach, other variants like artificial miRNA (amiRNA), miRNA mimics, and artificial transacting siRNAs (tasiRNAs) are being explored and successfully deployed in developing non-coding RNA-based genetically modified plants. The ncRNA-based gene manipulations are typified with mobile nature of silencing signals, interference from viral genome-derived suppressor proteins, and an obligation for meticulous computational analysis to prevaricate any inadvertent effects. In a broad sense, risk assessment inquiries for genetically modified plants based on the expression of ncRNAs are competently addressed by the environmental risk assessment (ERA) models, currently in vogue, designed for the first generation transgenic plants which are based on the expression of heterologous proteins. Nevertheless, transgenic plants functioning on the foundation of ncRNAs warrant due attention with respect to their unique attributes like off-target or non-target gene silencing effects, small RNAs (sRNAs) persistence, food and feed safety assessments, problems in detection and tracking of sRNAs in food, impact of ncRNAs in plant protection measures, effect of mutations etc. The role of recent developments in sequencing techniques like next generation sequencing (NGS) and the ERA paradigm of the different countries in vogue are also discussed in the context of ncRNA-based gene manipulations.     

Genetically modified crops and aquatic ecosystems: considerations for environmental risk assessment and non-target organism testing

Environmental risk assessments (ERA) support regulatory decisions for the commercial cultivation of genetically modified (GM) crops. The ERA for terrestrial agroecosystems is well-developed, whereas guidance for ERA of GM crops in aquatic ecosystems is not as well-defined. The purpose of this document is to demonstrate how comprehensive problem formulation can be used to develop a conceptual model and to identify potential exposure pathways, using Bacillus thuringiensis (Bt) maize as a case study. Within problem formulation, the insecticidal trait, the crop, the receiving environment, and protection goals were characterized, and a conceptual model was developed to identify routes through which aquatic organisms may be exposed to insecticidal proteins in maize tissue. Following a tiered approach for exposure assessment, worst-case exposures were estimated using standardized models, and factors mitigating exposure were described. Based on exposure estimates, shredders were identified as the functional group most likely to be exposed to insecticidal proteins. However, even using worst-case assumptions, the exposure of shredders to Bt maize was low and studies supporting the current risk assessments were deemed adequate. Determining if early tier toxicity studies are necessary to inform the risk assessment for a specific GM crop should be done on a case by case basis, and should be guided by thorough problem formulation and exposure assessment. The processes used to develop the Bt maize case study are intended to serve as a model for performing risk assessments on future traits and crops.     

EFSA’s scientific activities and achievements on the risk assessment of genetically modified organisms (GMOs) during its first decade of existence: looking back and ahead

Genetically modified organisms (GMOs) and derived food and feed products are subject to a risk analysis and regulatory approval before they can enter the market in the European Union (EU). In this risk analysis process, the role of the European Food Safety Authority (EFSA), which was created in 2002 in response to multiple food crises, is to independently assess and provide scientific advice to risk managers on any possible risks that the use of GMOs may pose to human and animal health and the environment. EFSA’s scientific advice is elaborated by its GMO Panel with the scientific support of several working groups and EFSA’s GMO Unit. This review presents EFSA’s scientific activities and highlights its achievements on the risk assessment of GMOs for the first 10 years of its existence. Since 2002, EFSA has issued 69 scientific opinions on genetically modified (GM) plant market registration applications, of which 62 for import and processing for food and feed uses, six for cultivation and one for the use of pollen (as or in food), and 19 scientific opinions on applications for marketing products made with GM microorganisms. Several guidelines for the risk assessment of GM plants, GM microorganisms and GM animals, as well as on specific issues such as post-market environmental monitoring (PMEM) were elaborated. EFSA also provided scientific advice upon request of the European Commission on safeguard clause and emergency measures invoked by EU Member States, annual PMEM reports, the potential risks of new biotechnology-based plant breeding techniques, evaluations of previously assessed GMOs in the light of new scientific publications, and the use of antibiotic resistance marker genes in GM plants. Future challenges relevant to the risk assessment of GMOs are discussed. EFSA’s risk assessments of GMO applications ensure that data are analysed and presented in a way that facilitates scientifically sound decisions that protect human and animal health and the environment.     

Using Ecological Risk Assessment Principles in a Source Water Protection Assessment

It has become increasingly common to apply ecological risk assessment (ERA) principles to watershed and regional scale environmental management. This article describes the application of watershed ERA principles to the development of a source water protection assessment and a strategic watershed management plan. The primary focus was on the protection of drinking water quality, a concern typically addressed by human health risk assessors. The approach emphasizes adaptations to the problem formulation phase of ERA (defining assessment endpoints, developing conceptual models and an analysis plan) suitable for watershed management planning in a multi-objective, multi-stressor context. Physical, chemical, and biological attributes were selected for primary drinking water quality assessment endpoints, and coupled with additional assessment endpoints relevant to other environmental and social management objectives. Conceptual models helped the planning team to better understand and communicate the multiple natural and human stressors in the watershed and the causal pathways by which they affected drinking water. The article provides an example of the types of adaptations that can make ERA principles suitable for watershed management related to human health goals, and illustrates the efficiency of integrating health and ecological assessments.     

Protection goals in environmental risk assessment: a practical approach

Policy protection goals are set up in most countries to minimise harm to the environment, humans and animals caused by human activities. Decisions on whether to approve new agricultural products, like pesticides or genetically modified (GM) crops, take into account these policy protection goals. To support decision-making, applications for approval of commercial uses of GM crops usually comprise an environmental risk assessment (ERA). These risk assessments are analytical tools, based on science, that follow a conceptual model that includes a problem formulation step where policy protection goals are considered. However, in most countries, risk assessors face major problems in that policy protection goals set in the legislation are stated in very broad terms and are too ambiguous to be directly applicable in ERAs. This means that risk assessors often have to interpret policy protection goals without clear guidance on what effects would be considered harmful. In this paper we propose a practical approach that may help risk assessors to translate policy protection goals into unambiguous (i.e., operational) protection goals and to establish relevant assessment endpoints and risk hypotheses that can be used in ERAs. Examples are provided to show how this approach can be applied to two areas of environmental concern relevant to the ERAs of GM crops.     

Problem formulation in the environmental risk assessment for genetically modified plants

Problem formulation is the first step in environmental risk assessment (ERA) where policy goals, scope, assessment endpoints, and methodology are distilled to an explicitly stated problem and approach for analysis. The consistency and utility of ERAs for genetically modified (GM) plants can be improved through rigorous problem formulation (PF), producing an analysis plan that describes relevant exposure scenarios and the potential consequences of these scenarios. A properly executed PF assures the relevance of ERA outcomes for decision-making. Adopting a harmonized approach to problem formulation should bring about greater uniformity in the ERA process for GM plants among regulatory regimes globally. This paper is the product of an international expert group convened by the International Life Sciences Institute (ILSI) Research Foundation.     

Characterising microbial protein test substances and establishing their equivalence with plant-produced proteins for use in risk assessments of transgenic crops

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.     

Criteria for selection of surrogates used to study the fate and control of pathogens in the environment

This article defines the term surrogate as an organism, particle, or substance used to study the fate of a pathogen in a specific environment. Pathogenic organisms, nonpathogenic organisms, and innocuous particles have been used as surrogates for a variety of purposes, including studies on survival and transport as well as for method development and as "indicators" of certain conditions. This article develops a qualitative surrogate attribute prioritization process and allows investigators to select a surrogate by systematically detailing the experimental process and prioritizing attributes. The results are described through the use of case studies of various laboratories that have used this process. This article also discusses the history of surrogate and microbial indicator use and outlines the method by which surrogates can be used when conducting a quantitative microbial risk assessment. The ultimate goal of selecting a sufficiently representative surrogate is to improve public health through a health-based risk assessment framework. Under- or overestimating the resistance, inactivation, or movement may negatively impact risk assessments that, in turn, will impact health assessments and estimated safety levels. Reducing uncertainty in a risk assessment is one of the objectives of using surrogates and the ultimate motive for any experiment investigating potential exposure of a pathogen.     

新加坡农业生物技术年报（2020）

目前,新加坡国内还没有任何植物生物技术投入商业化生产。截至2020年10月,新加坡共有43种转基因（genetically engineered,GE）植物产品获准用作食品或食品成分。新加坡遗传改良咨询委员会（Genetic Modification Advisory Committee,GMAC）最近修订了关于基因叠加事件的法规,采用“高覆盖低”的方法,对来源于先前GMAC认可的较低阶组合的高阶叠加事件组合豁免监管评估。     

Environmental risk assessment of transgenic miraculin-accumulating tomato in a confined field trial in Japan

The commercial use of genetically modified (GM) crops requires prior assessment of the risks to the environment when these crops are grown in the field or distributed. Assessments protocols vary across countries and GM crop events, but there is a common need to assess environmental biosafety. In this study, we conducted an environmental risk assessment in a confined field of GM tomato plants that can produce miraculin, a taste-altering protein that causes sour tastes to be perceived as sweet, for practical use in Japan. The evaluation was conducted for 1) competitiveness (the ability to compete with wild plants for nutrients, sunlight, and growing areas and prevent their growth) and 2) the production of toxic substances (the ability to produce substances that interfere with the habitat and growth of wild plants, animals, and microorganisms). Investigations of plant morphology and growth characteristics as well as tolerance to low temperature during early growth and overwintering for assessment endpoints related to competitiveness showed no biologically meaningful difference between GM tomato and non-GM tomato. In addition, harmful substances in plant residues and root secretions were assessed by the plow-in method, succeeding crop test and soil microflora tests, and it was determined that GM tomato does not exhibit an increase in harmful substances. Based on these results, it was concluded that GM miraculin-accumulating tomato is comparable to conventional tomato and is unlikely to have unintended adverse effects in the natural environment of Japan.     

Applicability of indicator monitoring to ecological risk assessment

Although ecological risk assessment (ERA) and environmental monitoring would seem to be potentially complimentary activities, they have been disjunct in practice. This is because of differences in goals and products. Environmental monitoring determines status and trends in indicators to determine whether the environment is improving. ERA estimates effects of stressors on endpoint attributes to support decision making. Indicators are, by definition, indicative of some unmeasured condition. Assessment endpoints are valued properties of the environment that are susceptible to stressors of concern. Indicators are justified by the logic of the monitoring program, which may be self-referential. Assessment endpoints are justified by their potential susceptibility and by environmental policies and public values. Indicators are often expressed in terms of indices or scores that obscure the actual condition of the environment. Because assessment endpoints must be clear to decision makers and the public, they require real units of actual environmental properties. Monitoring programs are peripherally concerned about causal relationships, while risk assessment is devoted to elucidating causal relationships. As a result, risk assessments may use the results of monitoring studies, but only after disaggregating the indicators to their components and choosing those that are appropriate. Monitoring programs could be more useful if they used a risk-based approach to address important problems rather than simply tracking indicators.     

Harmonization of regulations for invertebrate biocontrol agents in Europe: progress,problems and solutions

The use of non‐native invertebrate biological control agents (IBCAs) in Europe is not covered by a Directive equivalent to that which regulates biocontrol with microorganisms or the genetic modification of crop plants. Regulation is at the discretion of individual member states and largely derived from national legislation on pesticides, plant health or environmental protection. There is no EU country with regulation of IBCAs that requires information on the microbial symbiont content of candidate species, and in the absence of horizontal transfer under natural conditions, this policy is unlikely to change. Although there have been few reported negative effects linked to the import and release of IBCAs, a number of countries have introduced or revised their regulatory frameworks in recent years. This article reviews major developments in the regulation and environmental risk assessment (ERA) of IBCAs in Europe over the last 10 years including: the fragmented pattern of regulation between countries, variation in information requirements for release licences, format and methods of ERA for different taxonomic groups of IBCAs, use and updating of the European Plant Protection Organisation Positive List, sources of expert advice on ERA data, communication between IBCA regulators, and options for the provision of international leadership to coordinate regulatory and ERA‐related issues with IBCA‐based biocontrol in Europe.     

A Strategy for Using Weight-of-Evidence Methods in Ecological Risk Assessments

Our review of existing approaches and regulatory uses of weight-of-evidence (WOE) methods suggested the need for a practical strategy for deploying WOE within a predictive ecological risk assessment (ERA). WOE is the process of considering strengths and weaknesses of various pieces of information in order to inform a decision being made among competing alternatives. A predictive ERA uses existing information relating cause and effect to estimate the probability that today's action X will lead to tomorrow's adverse outcome Y. There appears to be no practical guidance for use of WOE in predictive assessments. We therefore propose a strategy for using a WOE approach, within an ERA framework, to weigh and integrate outcomes from various lines of evidence to estimate the probability of an adverse outcome in an assessment endpoint. An ERA framework is necessary to connect the results of an assessment to the management goals of concern to decision-makers and stakeholders. Within that framework, a WOE approach provides a consistent and transparent means of interpreting the myriad types of data and information gathered during a complex ecological assessment. Impediments to application of WOE are discussed, including limited regulatory guidance, limited prior regulatory use, and persistent reliance on threshold-based decision-making.     

Importance of functional classification in the use of carabids for the environmental risk assessment of the GE crops and other agricultural practices

Carabids(Coleoptera:Carabidae)seem to be suitable bioindicalors of the environmental impacts of novel agrotechnologies,including deployment of the genetically engineered(GE)crops.In this article,we describe our effort to employ carabids in the environmental risk assessment(ERA).GE maize MON88017,its near-isogenic hybrid nontreated or treated with the soil insccticide chlorpyrifos,and two reference hybrids were used to compare three different ways how to utilize carabids in ERA.The analysis of abundance of all captured carabids or of the most abundant carabid specics did not disclose any differences between the treatments.The analysis based on the categories of functional traits revealed distinct fecatures of some treatments and proved suitable for ERA because it permitted field data transportability in spite of different species compositions.Our results indicate that GE maize has no detrimental environmental effecl,On the other hand,we found significant trends toward lower abundance and lower species number(including analysis of all carabid species together)in plots treated with the insecticide,and some tendencies to higher abundance and higher species number in plots sown with the reference hybrid PR38N86.Using functional group indicators alows identification of unintended changes in ecological functions of agroecosystem and comparability across geographics.We recommend data evaluation at the level of the categories of functional traits in ERA of GE crops and other agricultural practices.     

Potential use of an arthropod database to support the non-target risk assessment and monitoring of transgenic plants

Worldwide, plants obtained through genetic modification are subject to a risk analysis and regulatory approval before they can enter the market. An area of concern addressed in environmental risk assessments is the potential of genetically modified (GM) plants to adversely affect non-target arthropods and the valued ecosystem services they provide. Environmental risk assessments are conducted case-by-case for each GM plant taking into account the plant species, its trait(s), the receiving environments into which the GM plant is to be released and its intended uses, and the combination of these characteristics. To facilitate the non-target risk assessment of GM plants, information on arthropods found in relevant agro-ecosystems in Europe has been compiled in a publicly available database of bio-ecological information during a project commissioned by the European Food Safety Authority (EFSA). Using different hypothetical GM maize case studies, we demonstrate how the information contained in the database can assist in identifying valued species that may be at risk and in selecting suitable species for laboratory testing, higher-tier studies, as well as post-market environmental monitoring.     

Assessment of unanticipated unintended effects of genetically modified plants on non‐target organisms: a controversy worthy of pursuit?

A typical risk hypothesis addressed during the environmental risk assessment (ERA) of genetically modified (GM) plants for cultivation is that the novel traits intentionally introduced into GM plants do not adversely affect non‐target organisms (NTOs). However, genetic modification may potentially also lead to unintended changes in the GM plant which could raise safety concerns. Therefore, the European Food Safety Authority (EFSA) advocates the characterization of ecological interactions between the GM plant and representative NTOs as part of the ERA of GM plants for cultivation in the European Union. Yet, this requirement is not unanimously accepted by stakeholders. Here, we present EFSA's approach to assess potential adverse effects on NTOs and summarize some of the stakeholders' views, mostly opposing EFSA's position on scientific grounds.     

Transportability of confined field trial data for environmental risk assessment of genetically engineered plants: a conceptual framework

It is commonly held that confined field trials (CFTs) used to evaluate the potential adverse environmental impacts of a genetically engineered (GE) plant should be conducted in each country where cultivation is intended, even when relevant and potentially sufficient data are already available from studies conducted elsewhere. The acceptance of data generated in CFTs “out of country” can only be realized in practice if the agro-climatic zone where a CFT is conducted is demonstrably representative of the agro-climatic zones in those geographies to which the data will be transported. In an attempt to elaborate this idea, a multi-disciplinary Working Group of scientists collaborated to develop a conceptual framework and associated process that can be used by the regulated and regulatory communities to support transportability of CFT data for environmental risk assessment (ERA). As proposed here, application of the conceptual framework provides a scientifically defensible process for evaluating if existing CFT data from remote sites are relevant and/or sufficient for local ERAs. Additionally, it promotes a strategic approach to identifying CFT site locations so that field data will be transportable from one regulatory jurisdiction to another. Application of the framework and process should be particularly beneficial to public sector product developers and small enterprises that develop innovative GE events but cannot afford to replicate redundant CFTs, and to regulatory authorities seeking to improve the deployment of limited institutional resources.