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Induction of Antiphytopathogenic Metabolite and Squalene Production and Phytotoxin Elimination by Adjustment of the Mode of Fermentation in Cocultures of Phytopathogenic Nigrospora oryzae and Irpex lacteus
journal contribution
posted on 2019-10-18, 16:35 authored by Ya-Mei Wu, Qing-Yan Zhou, Xue-Qiong Yang, Yu-Jie Luo, Jing-Jing Qian, Shi-Xi Liu, Ya-Bin Yang, Zhong-Tao DingThe investigation of the metabolites
from different cocultures
of Nigrospora oryzae and Irpex lacteus in solid medium revealed two new squalenes (1 and 2); one new azaphilone (3); two new tremulane
sesquiterpenes (4 and 5); and three known
compounds, conocenol B (6), conocenol C (7), and 4-(4-dihydroxymethylphenoxy)benzaldehyde (8).
The antagonistic relationship was examined by studying metabolite
production. The production of compounds 6 and 8 by I. lacteus after the induction of coculture
indicated significant selectivity for antifungal activity against
phytopathogenic N. oryzae, with MICs of 16 μg/mL;
compounds 6 and 8 also exhibited antifungal
activities in vivo against Cerasus cerasoides infected
by N. oryzae at concentrations of 100 μg/mL.
New compounds 2 and 4 showed antifungal
activities against Colletotrichum gloeosporioides, with MICs of 8 μg/mL, and compound 4 showed
antifungal activity against Didymella glomerata with
an MIC of 1 μg/mL. These results indicate that the mutually
antagonistic relationship in the coculture of the phytopathogen and
the endophyte can result in antibiotics that inhibit the phytopathogen
and downregulate the production of phytotoxins by phytopathogenic N. oryzae. New compound 5 from I. lacteus showed weak activity against acetylcholinesterase (AChE), with an
inhibition ratio of 16% at a concentration of 50 μM.