Work

A comparative study of the sorption, persistence, and bioactivity of the enantiopure and racemic forms of abscisic acid in soil under different application regimes

Year: 2025

Type: article

Abstract: The plant growth regulatory activity of both enantiomers of abscisic acid (ABA) provides a rationale for evaluating the potential benefits of using racemic ABA (RS-ABA) over S-ABA as a plant protection product. For soil application, where phytohormone stability is an important issue, the use of either S-ABA or RS-ABA would require a thorough evaluation of their enantioselective behavior in soil. In this work, a comparative study of the bioactivity of S- and RS-ABA under different regimes of soil application was performed, using Eruca sativa as a target test plant. Under soilless conditions (Petri-dish experiments), S-ABA inhibited the germination of Eruca sativa at lower concentrations (IC 50 = 1.1 mg/L) than RS-ABA (IC 50 = 1.9 mg/L). Conversely, in soil pot bioassays, RS-ABA inhibited germination at lower concentrations (IC 50 = 12 mg/L) than S-ABA (IC 50 = 30 mg/L). This was attributed to a more rapid inactivation of the S-enantiomer of ABA by biodegradation in soil in comparison with the R-ABA enantiomer. When applied post-emergence to soil-grown Eruca sativa seedlings, S-ABA exhibited greater activity than RS-ABA in foliar applications, while differences in activity became insignificant upon soil applications. A field experiment confirmed the germination inhibitory activity of both S-ABA and RS-ABA under real environmental conditions, with soil-applied RS-ABA showing slightly greater activity compared to S-ABA. The outcomes of this work demonstrate that the enantiomeric composition can significantly influence the effectiveness of ABA as a plant protection product, and suggest that racemic ABA may offer advantages over S-ABA in certain soil application scenarios due to a slower inactivation of the R-ABA enantiomer.

Source: Chemical and Biological Technologies in Agriculture

DOI: 10.1186/s40538-025-00896-7

Authors: María del Valle Muñoz-Muñoz, Rafael Celis, Rocío López-Cabeza

Institution: Instituto de Recursos Naturales y Agrobiología de Sevilla

Language: English

Topic: Pesticide and Herbicide Environmental Studies

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life on land, Zero hunger

Open Access status: gold

Estimated APC paid: $2,790