Work

Antimicrobial and Herbicidal Secondary Metabolites from Insect-Associated Fungus Leptosphaeria sp. FZN28 in Mecopoda elongata

Year: 2025

Type: article

Abstract: The global food security faces significant threats from phytopathogenic microbes and weeds. In this study, seven secondary metabolites (1–7) were isolated from the insect-associated fungus Leptosphaeria sp. FZN28 in Mecopoda elongata. Their structures were elucidated through a combination of spectroscopic analyses. In bioactive assays, peniciphenalenin E (1) exhibited great antimicrobial activities against Phytophthora capsici and Sclerotinia sclerotiorum, with EC50 values of 8.8 and 10.8 μg/mL, respectively. Scleroderolide (2) demonstrated EC50 values of 20.4 and 14.8 μg/mL against the same strains, respectively. Notably, as seen with in vitro assays, 100 μg/mL of 1 could effectively prevent infection of P. capsici with a protection efficacy of 69.1%, and compounds 1 and 2 at a concentration of 200 μg/mL could greatly inhibit disease development in S. sclerotiorum-infected cole leaves with inhibitory efficacies of 66.9% and 61.0%, respectively. Moreover, the two compounds could also affect the hyphal morphology of S. sclerotiorum and P. capsici via scanning electron microscope and transmission electron microscope. Additionally, compounds 1 and 2 at a concentration of 200 μg/mL could significantly inhibit the radicle growth and germ elongation of monocotyledon weed and dicotyledon weed, Echinochloa crusgalli and Eclipta prostrata. Considering their antimicrobial and herbicidal activities, compounds 1 and 2 showed promise for the development of new bio-pesticides.

Source: Agronomy

DOI: 10.3390/agronomy15122673