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A metabolite of endophytic fungus Cadophora orchidicola from Kalimeris indica serves as a potential fungicide and TLR 4 agonist
Author(s) -
Wang L.,
Shen J.,
Xu L.,
Gao J.,
Zhang C.,
Wang Y.,
Chen F.
Publication year - 2019
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.14239
Subject(s) - metabolite , biology , botrytis cinerea , plant use of endophytic fungi in defense , ec50 , secondary metabolite , fungicide , splenocyte , botany , microbiology and biotechnology , biochemistry , gene , in vitro
Aim To investigate the bioactive metabolite of endophytic fungus from Kalimeris indica . Methods and Results A strain ZJLQ 336 was separated from the leaves of K. indica . It was identified as Cadophora orchidicola based on the phylogenetic analysis of ITS ‐ rDNA sequences. From the fermentation broth a metabolite cercosporamide (compound 1 ) was isolated, and its structure was determined by spectroscopic analysis. Additionally, this compound was subjected to bioactivity assays, including antifungal activity against seven plant pathogenic fungi, as well as its potential immunoregulatory effects on HEK ‐ BLUE ™‐ hTLR 4 cells, splenocytes and macrophages. The results showed that cercosporamide had strong growth inhibition against five common plant pathogenic fungi, including Pestalotia diospyri , Botrytis cinerea , Fusarium oxysporum , Sclerotium rolfsii and Penicillum digitatum with EC 50 values of 5·29 × 10 −3 , 0·61, 0·93, 2·89 and 6·7 μ g ml −1 respectively. Among which S. rolfsii was one of the main pathogens in K. indica . Moreover, cercosporamide not only significantly stimulated TLR 4 activation, splenocyte proliferation and production of cytokines, IFN ‐γ and TNF ‐α, but also up‐regulated the production of TNF ‐α and NO in RAW 264.7 macrophages clearly. Conclusions This is the first report of endophytic C. orchidicola from K. indica and its metabolite cercosporamide. The results of pharmacological tests highlight the potential fungicide and TLR 4 agonist of cercosporamide. Significance and Impact of the Study This study indicates endophytic fungi are good resources for natural bioactive metabolites. It also suggests that cercosporamide is a potential fungicide and TLR 4 agonist.