Novel Lead Compound Discovery from Aspergillus fumigatus 1T‑2 against Meloidogyne incognita Based on a Chemical Ecology Study

To
replace biohazardous nematicides, there is an ever-increasing
need to identify natural product-based agents to contain root-knot nematodes
(RKNs) in agriculture. In this chemical ecology study, an antagonistic
fungus Aspergillus fumigatus 1T-2,
which could cause the formation of withering of the gut and vacuole-like
structures in the nematode body, was isolated based on the gradually
increased antagonistic interactions between the soil fungi and RKNs.
Based on these typical morphological characteristics, a potent nematode-antagonistic
compound 2-furoic acid, which had a simple structure, was successfully
identified from 1T-2 fermentation broth by liquid chromatography–mass spectrometry (LC–MS). 2-Furoic
acid showed effective mortality activity in vitro, of which the LC50 value to Megalaima
incognita at 24 h was 37.75 μg/mL. 2-Furoic
acid had similar mortality activity to the positive control fosthiazate
at 30 μg/mL. Continuous 2-furoic acid exposure had obvious negative
influences on both nematode vitality and egg hatchability. Notably,
significant variations were observed in nematodes and eggs with 2-furoic
acid treatment, which might be induced by novel nematocidal mechanisms.
Furthermore, the 1T-2 fermentation broth and 2-furoic acid had significant
control efficacy on M. incognita under
the greenhouse test-tube assay. Overall, these findings provide valuable
insights into the use of 2-furoic acid with biocontrol potential as
a preferable lead structure for the development of innovative nematicides.