αβ-Dehydrocurvularin isolated from the fungus Aspergillus welwitschiae effectively inhibited the behaviour and development of the root-knot nematode Meloidogyne graminicola in rice roots

Abstract

Background: The root-knot nematode Meloidogyne graminicola has become a serious threat to rice production as a result of the cultivation changes from transplanting to direct seeding. The nematicidal activity of Aspergillus welwitschiae have been investigated in vitro, and the disease control efficacy of the active compound has been evaluated under greenhouse and field conditions. Results: The active compound αβ-dehydrocurvularin (αβ-DC), isolated by nematicidal assay-directed fractionation, showed significant nematicidal activity against M. graminicola, with a median lethal concentration (LC 50) value of 122.2 μg mL − 1. αβ-DC effectively decreased the attraction of rice roots to nematodes and the infection of nematodes and also suppressed the development of nematodes under greenhouse conditions. Moreover, αβ-DC efficiently reduced the root gall index under field conditions. Conclusions: To our knowledge, this is the first report to describe the nematicidal activity of αβ-DC against M. graminicola. The results obtained under greenhouse and field conditions provide a basis for developing commercial formulations from αβ-DC to control M. graminicola in the future.

Untargeted metabolomics screening reveals unique secondary metabolite production from Alternaria section Alternaria

“…Among the dehydrocurvularin analogs tested, dehydrocurvularin is consistently associated with the most pronounced phytotoxic response. In addition to phytotoxicity, dehydrocurvularin exhibits antifungal activity through suppression of sporulation and spore germination (Hyeon et al, 1976), modest antibacterial activity against several Gram-positive and Gram-negative bacteria (such as Bacillus subtilis, Staphylococcus aureus, and Escherichia coli; Caputo and Viola, 1977), and significant nematicidal activity against Meloidogyne graminicola (Xiang et al, 2020). Dehydrocurvularin also disrupted mitosis in sea urchin embryos (Kobayashi et al, 1988).…”

Microbes vs. Nematodes: Insights into Biocontrol through Antagonistic Organisms to Control Root-Knot Nematodes

“…Drenching with αβ-DC significantly reduced penetration by nematodes and thus reduced infection in rice root and suppressed the development of females. αβ-DC significantly reduced the root gall index under field conditions [ 108 ].…”

Natural nematicidal metabolites and advances in their biocontrol capacity on plant parasitic nematodes

“…They exhibited activity against C. elegans with LD 50 values of 12.5–50 μg mL −1 at 18 h. 55 An active compound, αβ-dehydrocurvularin (αβ-DC) 128 , was isolated from Aspergillus welwitschiae ; it exhibited activity against Meloidogyne graminicola , a plant root-knot nematode. 56 Gibepyrones D 129 and G 130 were produced by endophyte Fusarium oxysporum 162, and were active against M. incognita . 57 Grammicin 131 was identified as the nematicidal metabolite isolated from an endolichenic fungus, Xylaria grammica KCTC 13121BP, which exhibited nematicidal and egg-hatching inhibitory effects toward M. incognita .…”

“…They exhibited activity against C. elegans with LD 50 values of 12.5-50 mg mL −1 at 18 h. 55 An active compound, ab-dehydrocurvularin (ab-DC) 128, was isolated from Aspergillus welwitschiae; it exhibited activity against Meloidogyne graminicola, a plant root-knot nematode. 56 Gibepyrones D 129 and G 130 were produced by endophyte 61 A novel antifungal metabolite SH2 141, was puried from Streptomyces hydrogenans DH16 and proved to be a potent nematicidal agent; it caused 100% J2 mortality and 0% egg hatching of M. incognita aer 72 and 160 h, respectively at 200 mg mL −1 . This strain could potentially be developed into a safe biopesticide.…”