<i>Cis</i>-3-Indoleacrylic Acid: A Nematicidal\nCompound from Streptomyces youssoufiensis YMF3.862 as V‑ATPase Inhibitor on Meloidogyne\nincognita

The\napplication of the bionematicides derived from microorganisms\nand their secondary metabolites represents a promising strategy for\nmanaging root-knot nematodes. In this study, a nematicidal compound, <i>cis</i>-3-indoleacrylic acid, was isolated from Streptomyces youssoufiensis YMF3.862. This compound\ncaused Meloidogyne incognita juveniles\nto have swollen bodies with apparent cracks on the cuticle surface.\nThe LC<sub>50</sub> value of <i>cis</i>-3-indoleacrylic\nacid against juveniles was 16.31 μg/mL 24 h of post-treatment. <i>Cis</i>-3-indoleacrylic acid at 20 μg/mL significantly\ninhibited V-ATPase expression and remarkably decreased enzyme activity\nby 84.41%. As an inhibitor of V-ATPase, <i>cis</i>-3-indoleacrylic\nacid caused significant H<sup>+</sup> accumulation in nematode bodies,\nresulting in lower intracellular pH values and higher extracellular\npH values of M. incognita. Application\nof 50 μg/mL <i>cis</i>-3-indoleacrylic acid generated\na 71.06% control efficiency against M. incognita on tomatoes. The combination results of this study indicated that <i>cis</i>-3-indoleacrylic acid can be developed as a natural nematicide\nfor controlling M. incognita.