The herbicidal activity and mechanism of Talaromyces purpureogenusCY‐1 metabolites

Abstract BACKGROUND Studies have shown that Talaromyces can produce a large number of secondary metabolites in its metabolic process, many of which have good insecticidal, antibacterial, antitumor, antiviral and other biological activities. In order to explore the herbicidal activity and mechanism of Talaromyces purpureogenus CY‐1, we determined the inhibitory effect of the fermentation broth of the CY‐1 strain on weeds, identified the major active components, and further investigated the herbicidal mechanism. RESULT The results showed that CY‐1, with IC50 values of 5.40 g/L and 4.39 g/L, respectively, exhibited good herbicidal activity against Xanthium sibiricum and Amaranthus lividus . Spraying CY‐1 strain fermentation broth on redroot pigweed resulted in plant protection efficiencies and fresh weight protection efficiencies of 83.7% and 87%, respectively. The active component identified in the broth was 2‐(3‐hydroxybenzoyloxy) acrylic acid. Treatment of Amaranthus lividus with 2‐(3‐hydroxybenzoyloxy) acrylic acid resulted in trends of increasing superoxide dismutase activity, peroxidase activity, respiratory rate, cytochrome oxidase activity, and soluble protein content, followed by a decrease. Peroxidase activity, relative conductance and malondialdehyde content gradually increased, while acetyl lactate synthase and glutamine synthetase initially decreased and gradually returned to normal. The soluble sugar content showed a gradual decrease. CONCLUSION The findings of the present study indicate that 2‐(3‐hydroxybenzoyloxy) acrylic acid can induce oxidative stress in plants, damaging plant cell walls, weakening respiratory activity, inhibiting protein synthesis and sugar metabolism, ultimately leading to weed wilting and death. © 2024 Society of Chemical Industry.