Development of a standard protocol for the assessment of reproductive endpoints in non-target terrestrial plants (NTTP) under greenhouse conditions.

Ecotoxicological testing to assess the effects of plant protection products on Non-Target Terrestrial Plants (NTTPs) under greenhouse conditions is conducted according to standard guidelines (e.g. OECD 208 and OECD 227). EFSA’s Scientific Opinion on the risk assessment of plant protection products (PPP) for non-target terrestrial plants (2014) raised awareness of a potential need to assess effects on plant reproduction, e.g. seed production. Literature reviews and experimental studies evaluated the feasibility and relevance of plant reproductive endpoints (e.g. Christl et al. 2020, Duffner et al. 2020). In summary, they concluded that (a) assessment of reproductive endpoints in selected plant species is in principle feasible, (b) there is no clear trend that reproductive endpoints are more sensitive than vegetative ones and (c) specific cases may exist where reproductive endpoints appear to be more sensitive depending on e.g., mode of action of a plant protection product and/or test species. For cases where effects on reproductive endpoints need to be assessed for regulatory purposes, a standard test protocol is required. Thus, a working group within the SETAC Plant Interest Group was launched in November 2021 to collect and analyze relevant and available data and experiences in order to provide guidance for a plant reproduction protocol. The working group meets regularly in three subgroups covering (a) Plant species selection, (b) Challenges & Restrictions and (c) Protocol elements to develop the protocol. The objective of this poster is to create awareness of the topic, to provide an overview and status of this working group, and to present some of the challenges and foster a discussion on possible solutions in order to obtain a broadly acceptable standard test protocol. References: Christl, H., T. Hoen, and U. Zumkier. 2020. Comparative Assessment of Vegetative and Reproductive Terrestrial Plant Species Endpoints from Exposure to Herbicides and Potential Environmental Implications: A Review. Integrated Environmental Assessment and Management 16:166-183.Duffner, A., T. Moser, and M. P. Candolfi. 2020. Feasibility of assessing vegetative and generative endpoints of crop- and non- crop terrestrial plant species for non-target terrestrial plant (NTTP) regulatory testing under greenhouse conditions. PLOS ONE 15:e0230155.EFSA. 2014. Scientific Opinion addressing the state of the science on risk assessment of plant protection products for non-target terrestrial plants. EFS

Impact/Purpose

Plant reproduction (seed production) is an important potential endpoint for risk assessments of the effects of pesticides (especially herbicides) to non-target terrestrial plants. The standard plant testing guidelines only consider seed germination and vegetative growth responses, which may nonadequately consider important crop production and ecosystem responses which involve seed production. The Society of Environmental Toxicology and Chemistry Global Plant Interest group has a working group which as launched in November 2021 to collect and analyze relevant and available data and experiences in order to provide guidance for a plant reproduction protocol. This presentation will describe an overview and status of this working group, and to present some of the challenges and foster a discussion on possible solutions in order to obtain a broadly acceptable standard test protocol. This protocol will be of interest to EPA's Office of Chemical Safety and Pollution Prevention as it seeks to have the most relevant data as it conducts its risk assessments for pesticide (especially herbicide) registrations that may affect non-target plants, including those in natural ecosystems.

Citation

Duffer, A., D. Olszyk, B. Flickinger, F. Huerta, H. Teresiak, G. Kraetzig, J. Davies, L. Privitera, AND C. Mihan. Development of a standard protocol for the assessment of reproductive endpoints in non-target terrestrial plants (NTTP) under greenhouse conditions. SETAC Europe, 33rd Annual Meeting, Dublin, Ireland, IRELAND, April 30 - May 04, 2023.