Sesquiterpenes and Cyclodepsipeptides from Marine-Derived Fungus Trichoderma longibrachiatum and Their Antagonistic Activities against Soil-Borne Pathogens

Abstract

Soil-borne pathogens, including phytopathogenic fungi and root-knot nematodes, could synergistically invade vegetable roots and result in serious economic losses. The genus of Trichoderma has been proven to be a promising reservoir of biocontrol agents in agriculture. In this study, the search for antagonistic metabolites from a marine-derived fungus, Trichoderma longibrachiatum, obtained two structural series of sesquiterpenes 1–6 and cyclodepsipeptides 7–9. Notably, the novel 1 was a rare norsesquiterpene characterized by an unprecedented tricyclic-6/5/5-[4.3.1.01,6]-decane skeleton. Their structures were elucidated by extensive spectroscopic analyses, while the absolute configuration of novel 1 was determined by the comparison of experimental and calculated ECD spectra. The novel 1 and known 2 and 3 showed significant antifungal activities against Colletotrichum lagrnarium with MIC values of 8, 16, and 16 μg/mL respectively, even better than those of the commonly used synthetic fungicide carbendazim with 32 μg/mL. They also exhibited antifungal potential against carbendazim-resistant Botrytis cinerea. Cyclodepsipeptides 7–9 showed moderate nematicidal activities against the southern root-knot nematode (Meloidogyne incognita). This study constitutes the first report on the antagonistic effects of metabolites from T. Longibrachiatum against soil-borne pathogens, also highlighting the integrated antagonistic potential of marine-derived T. Longibrachiatum as a biocontrol agent.

In Vitro and In Vivo Antifungal Activity of Sorbicillinoids Produced by Trichoderma longibrachiatum

“…The fungus T. longibrachiatum is generally isolated from terrestrial soil and plants and has broad-spectrum and potential antagonistic effects in inhibiting the growth of plant pathogenic fungi [14][15][16][17]. In terms of the antifungal compounds derived from T. longibrachiatum, it has been reported that a new rare norsesquiterpene exhibited a potent antagonistic ability against Colletotrichum lagenarium, C. fragariae, carbendazim-resistant strains of Botrytis cinerea, and Fusarium spp.…”

“…In terms of the antifungal compounds derived from T. longibrachiatum, it has been reported that a new rare norsesquiterpene exhibited a potent antagonistic ability against Colletotrichum lagenarium, C. fragariae, carbendazim-resistant strains of Botrytis cinerea, and Fusarium spp. [15]. However, there is still a lack of papers describing the in vitro and in vivo antifungal activities of secondary metabolites produced by T. longibrachiatum against plant diseases caused by fungi.…”

Antibacterial Activities of the Extracts of Sponge-Associated Fungus Trichoderma longibrachiatum against Pathogenic Bacteria

“…Some of t he compounds contained in T. longibranchiatum extract have been researched. Extract of ethyl acetate from marine-derived fungus T. longibrachiatum from Jiaozhou Bay, Qingdao, Chi na contained two st ructural series of sesquiterpenes and cyclodepsipeptides, both have antifungal activity (Du et al, 2020). Other studies reported that the extract of ethyl acetate of T. longibrachiatum associated with the sponge Haliclona sp.…”

Screening of Marine Bioactive Antimicrobial Compounds for Plant Pathogens

“…Thus far, scientists have isolated numerous natural products with antitumor, antibacterial, and other biological activities from marine organisms [ 12 , 15 , 16 , 17 , 18 , 19 ]. Modern pharmacological studies also demonstrate that many marine biological metabolites show good effects on killing phytopathogenic bacteria, which possibly can be used for developing biological fungicides [ 20 , 21 , 22 , 23 , 24 ]. In fact, at the present, marine organisms have become an important resource for developing new biological fungicides to control plant diseases.…”