Effect of Bt toxin Cry1Ab on two freshwater caddisfly shredders - an attempt to establish dose-effect relationships through food-spiking

Assessing Effects of Genetically Modified Plant Material on the Aquatic Environment Using higher-tier Studies

Genetically modified organisms are used extensively in agriculture. To assess potential side effects of genetically modified (GM) plant material on aquatic ecosystems, only a very small number of higher-tier studies have been performed. At the same time, these studies are particularly important for comprehensive risk assessment covering complex ecological relationships. Here we evaluate the methods of experimental higher-tier effect studies with GM plant material (or Bt toxin) in comparison to those well-established for pesticides. A major difference is that nominal test concentrations and thus dose-response relationships cannot easily be produced with GM plant material. Another important difference, particularly to non-systemic pesticides, is that aquatic organisms are exposed to GM plant material primarily through their feed. These and further differences in test requirements, compared with pesticides, call for a standardisation for GM-specific higher-tier study designs to assess their potentially complex effects in the aquatic ecosystems comprehensively.

Novel Field-Based Protein Detection Method Using Light Transmission Spectroscopy and Antibody Functionalized Gold Nanoparticles

Protein detection is a universal tool critical to many applications in medicine, agriculture, and biotechnology. We developed a novel protein detection method combining light transmission spectroscopy and particle-size analysis of gold nanospheres monovalently functionalized with polyclonal antibodies and applied it to an emerging challenge for such technologies─the monitoring of environmental proteins (eProteins) present in natural aquatic systems. These are an underreported source of pollution and include the pseudopersistent Cry toxins that enter aquatic ecosystems from surrounding genetically engineered crops. The assay is capable of detecting proteins in complex matrices, such as water samples collected in the field, making it a competitive assay for eProtein detection. It is sensitive, reaching 1.25 ng mL^-1, and we demonstrate its application to the detection of Cry1Ab from subsurface tile-drain and streamwater samples from agricultural waterways. The assay can also be quickly adapted for other protein detection applications in the future.

Fate of Environmental Proteins (eProteins) from Genetically Engineered Crops in Streams is Controlled by Water pH and Ecosystem Metabolism

Environmental proteins (eProteins), such as Cry proteins associated with genetically engineered (GE) organisms, are present in ecosystems worldwide, but only rarely reach concentrations with detectable ecosystem-level impacts. Despite their ubiquity, the degradation and fate of Cry and other eProteins are mostly unknown. Here, we report the results of an experiment where we added Cry proteins leached from GE Bt maize to a suite of 19 recirculating experimental streams. We found that Cry exhibited a biphasic degradation with an initial phase of rapid and variable degradation within 1 h, followed by a slow and steady phase of degradation with traces of protein persisting after 48 h. The initial degradation was correlated with heterotrophic respiration and water column dissolved oxygen, confirming a previously documented association with stream metabolism. However, protein degradation persisted even with no biofilm and was faster at a more acidic pH, suggesting that water chemistry is also a critical factor in both degradation and subsequent detection. We suggest that Cry, as well as other eProteins, will have a rapid degradation caused by denaturation of proteins and pH changes, which confirms that the detection of Cry proteins in natural streams must be the result of steady and consistent leaching into the environment.

Assessment of the 2018 post-market environmental monitoring report on the cultivation of genetically modified maize MON 810 in the EU

Following a request from the European Commission, the EFSA assessed the 2018 post-market environmental monitoring (PMEM) report on the cultivation of Cry1Ab-expressing maize event MON 810. Like previous years, there was partial compliance with refuge requirements by Spanish farmers growing MON 810 varieties. European and Mediterranean corn borer populations collected from north-eastern Spain during the 2018 maize growing season and tested for Cry1Ab susceptibility show no symptoms of resistance to maize MON 810. The assessment of farmer questionnaires and relevant scientific publications does not indicate any unanticipated adverse effects on human and animal health or the environment arising from the cultivation of maize MON 810. The report does not provide information about the use of existing networks involved in environmental monitoring. Overall, EFSA concludes that the evidence reported in the 2018 PMEM report does not invalidate previous EFSA evaluations on the safety of maize MON 810. However, as in previous years, EFSA identifies shortcomings on resistance monitoring that need revision in future reports. In particular, the monitoring plan, as implemented in 2018, is not sufficiently sensitive to detect the recommended 3% resistance allele frequency. Consequently, EFSA strongly recommends the consent holder to: (1) achieve full compliance with refuge obligations in areas where adoption of maize MON 810 is high; (2) increase the sensitivity of the monitoring plan and address previously mentioned limitations for resistance monitoring; and (3) perform an F2 screen on corn borer populations from north-eastern Spain. A fit-for-purpose farmer alert system may help to detect unexpected adverse effects associated with the cultivation of MON 810 varieties and be an alternative to the current farmer survey system. Moreover, relevant stakeholders should implement a methodological framework to enable making the best use of existing networks involved in environmental monitoring for the general surveillance of genetically modified plants.