# The Chemical Composition and Nematicidal Activity of Wasabi (Eutrema japonicum) Rhizome Extract Against Meloidogyne enterolobii

## TL;DR

This study shows that wasabi rhizome extract can effectively kill root-knot nematodes and identifies key compounds responsible for this activity.

## Contribution

The study identifies the nematicidal activity of Eutrema japonicum rhizome extract and isolates effective compounds like sec-butyl isothiocyanate and geraniol.

## Key findings

- The LC50 of E. japonicum rhizome extract on J2s was 69.590 mg/mL at 24 h and 22.336 mg/mL at 48 h.
- At 200 mg/mL, the extract achieved 88.93% J2 mortality and 88.14% egg hatching inhibition.
- Sec-butyl isothiocyanate and geraniol showed high nematicidal activity and potential mechanisms were explored.

## Abstract

Eutrema japonicum is a perennial herb belonging to the Eutrema genus in the crucifer family. In recent years, numerous substances with notable pharmacological activities have been successfully isolated from E. japonicum. Despite significant advancements in related research, the efficacy of the rhizome extract of E. japonicum against root-knot nematodes remains unknown. In this study, the rhizome extract of E. japonicum was used as raw material to demonstrate the inhibitory and nematicidal effects of the extract on Meloidogyne enterolobii. The results showed that the LC50 of the E. japonicum rhizome extract on second-stage juveniles (J2s) was 69.590 mg/mL and 22.336 mg/mL at 24 h and 48 h after treatment, respectively. The mortality rate of J2s reached 88.93% at 48 h post-treatment when the concentration was 200 mg/mL, and the inhibition rate of single-egg hatching reached 88.14%. This study analyzed the chemical composition of the ethanol extract of E. japonicum, and 10 organosulfur compounds and lipid compounds with insecticidal and antibacterial effects were preliminarily screened out. Among them, sec-butyl isothiocyanate and geraniol were further investigated for their nematicidal activity, demonstrating high efficacy against M. enterolobii. Moreover, we conducted network pharmacology analysis and RT-qPCR analysis to predict the potential inhibitory mechanisms of sec-butyl isothiocyanate and geraniol on M. enterolobii. These findings offer a scientific foundation and theoretical framework for utilizing E.japonicum as a potential raw material for developing novel natural plant nematicides.