AUTHOR=Mbula Jean Pierre , Andres Maria Fe , Kitete Emmanuel M. , Kasiama N. G. , Tshilanda D. D. , Ngbolua K. N. , Tshibangu D. S. T. , Onautshu O. , González-Coloma Azucena , Mpiana Pius T. 

TITLE=Valorization of the essential oil from Drypetes gossweileri S. Moore (Putranjivaceae): in vitro, in vivo, and in silico nematicidal activity

JOURNAL=Frontiers in Plant Science

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1260360

DOI=10.3389/fpls.2023.1260360

ISSN=1664-462X

ABSTRACT=<p>The chemical composition, insect antifeedant, <italic>in vtro/in vivo</italic> nematicidal activity, phytotoxicity, and <italic>in silico</italic> nematicidal activity of the essential oil (EO) of the African medicinal plant <italic>Drypetes gossweileri</italic> were studied. Chemical analysis using GC/MS indicated that benzyl isothiocyanate (96.23%) was the major compound, followed by benzyl cyanide (1.38%). The biocidal effects of this oil were tested against insect pests and root-knot nematodes. All the insect species tested were significantly affected by the oil according to their feeding adaptations (<italic>Spodoptera littoralis</italic> and <italic>Myzus persicae</italic> were less affected than <italic>Rhopalosiphum padi</italic>) with efficient doses (EC<sub>50</sub>) of 29.4 8.3 μg/cm<sup>2</sup>, 14.744 8.3 μg/cm<sup>2</sup>, and 8.3 μg/cm<sup>2</sup>, respectively. The oil was highly effective against juveniles J2 of the nematode <italic>Meloidogyne javanica</italic>, with LC<sub>50</sub>–LC<sub>90</sub> values of 0.007 mg/mL–0.0113 mg/mL. <italic>D. gossweileri</italic> EO at minimum lethal concentrations (MLC) and below strongly inhibited egg hatching <italic>in vitro</italic>, whereas soil treatment caused a strong suppression of nematode population, infection frequency, and multiplication rate. The EO inhibited ryegrass (<italic>Lolium perenne</italic>) germination at 0.4 mg/mL, while at 0.1 mg/mL, its effects on germination, root and leaf growth were moderate (32.4%, 8.4%, and 18.3%, respectively). The tomato (<italic>Solanum lycopersicum</italic>) germination was not affected by the EO, but the root growth was reduced (56% at 0.1 mg/mL) at a dose 10 times higher than the LD<sub>50</sub> calculated for <italic>M. javanica</italic> J2 mortality. Molecular docking of the nematicidal effects of the oil using PyRx revealed a strong interaction between potassium chloride transporting KCC3 (PDB ID: 7D90) and benzyl cyanide at a distance of 2.20 A° with GLN C:350, followed by benzyl isothiocyanate at a distance of 2.78 A° with ARG B:294. The <italic>in vivo</italic> nematicidal effects of <italic>D. gossweileri</italic> EO on <italic>M. javanica</italic> penetration and reproduction in tomato roots further support the potential of this EO as a nematicidal agent with insect antifeedant effects, which could be used by local farmers for crop protection.</p>