Sublethal endpoints in non-target organism testing for insect-active GE crops

Authors: ROBERTS, ANDREW - International Life Sciences Institute (ILSI); BOECKMAN, CHAD - Corteva Agriscience; MÜHL, MARINA - Ministerio De Agricultura; ROMEIS, JÖRG - Agroscope; TEEM, JOHN - International Life Sciences Institute (ILSI); VALICENTE, FERNANDO - Embrapa; BROWN, JUDITH - University Of Arizona; EDWARDS, MARTIN - Newcastle University; LEVINE, STEVEN - Bayer Corporation; MELNICK, RACHEL - International Life Sciences Institute (ILSI); RODRIGUES, THAÍS - Greenlight Biosciences; VÉLEZ ARANGO, ANA MARÍA - University Of Nebraska; ZHOU, XUGUO - University Of Kentucky; Hellmich Ii, Richard

Submitted to: Frontiers in Bioengineering and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2021
Publication Date: 6/9/2021
Citation: Roberts, A., Boeckman, C.J., Mühl, M., Romeis, J., Teem, J., Valicente, F.H., Brown, J.K., Edwards, M.G., Levine, S.L., Melnick, R.L., Rodrigues, T.B., Vélez Arango, A., Zhou, X., Hellmich II, R.L. 2021. Sublethal endpoints in non-target organism testing for insect-active GE crops. Frontiers in Bioengineering and Biotechnology. 8. Article 556. https://doi.org/10.3389/fbioe.2020.00556.
DOI: https://doi.org/10.3389/fbioe.2020.00556

Interpretive Summary: Genetically engineered (GE) crops have been modified to have several beneficial traits for agriculture. Some crops produce substances that kill certain destructive crop-feeding insects, but do not harm animals other than insects. Researchers test for any possible negative effects on other insects (called ‘non-targets’), including beneficial species which pollinate plants or feed on pests. This environmental risk assessment is standardized and supports regulatory decision making. However, new technologies, such as RNA interference and novel insecticidal proteins, have recently been developed to enhance pest protection. These technologies have new modes of action. Although the overall assessment paradigm for GE plants is robust, there are ongoing discussions about the appropriate tests for these new types of GE plants. As a result, increasing attention is being paid to the use of sublethal endpoints and their value for environmental risk assessments. This review focuses on the current status and history of sublethal endpoint use in insect active GE crops, and evaluates the future use of sublethal endpoints for new and emerging technologies. This information is useful for industry, government, and academic stakeholders interested in testing for potential non-target effects of transgenic crops.

Technical Abstract: Historically, genetically engineered (GE) plants that have incorporated genes conferring insect protection have primarily used Cry proteins derived from Bacillus thuringiensis (Bt) to achieve their insecticidal phenotype. As a result, regulators have developed a level of familiarity and confidence in reviewing plants incorporating these insecticidal proteins. However, new technologies have been developed that produce GE plants that incorporate pest protection by triggering an RNA interference (RNAi) response through double-stranded RNA (dsRNA), or proteins other than Bt Cry proteins. These technologies have new modes of action. Although the overall assessment paradigm for GE plants is robust, there are ongoing discussions about the appropriate tests and measurement endpoints needed to inform non-target arthropod assessment for technologies that have a different mode of action than the Bt Cry proteins. As a result, increasing attention is being paid to the use of sublethal endpoints and their value for environmental risk assessment (ERA). This review focuses on the current status and history of sublethal endpoint use in insect active GE crops, and evaluates the future use of sublethal endpoints for new and emerging technologies. It builds upon presentations made at the Workshop on Sublethal Endpoints for NTO Testing for Non-Bt GE Crops (Washington DC, USA, 4–5 March 2019), and the discussions of government, academic and industry scientists convened for the purpose of reviewing the progress and status of sublethal endpoint testing in non-target organisms. This information is useful for industry, government, and academic stakeholders interested in testing for potential non-target effects of transgenic crops.