AUTHOR=Ding Zhuang , Wang Xiao , Kong Fan-Dong , Huang Hui-Ming , Zhao Yan-Na , Liu Min , Wang Zheng-Ping , Han Jun 

TITLE=Overexpression of Global Regulator Talae1 Leads to the Discovery of New Antifungal Polyketides From Endophytic Fungus Trichoderma afroharzianum

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.622785

DOI=10.3389/fmicb.2020.622785

ISSN=1664-302X

ABSTRACT=<p>Transcription regulation caused by global regulators exerts important effects on fungal secondary metabolism. By overexpression of the global regulator Talae1 in a <italic>Ficus elastica</italic>-associated fungus <italic>Trichoderma afroharzianum</italic>, two structurally new polyketides (<bold>1</bold> and <bold>2</bold>) that were newly produced in the transformant were isolated and identified. Their structures, including the absolute configurations, were elucidated through a combination of high resolution mass spectrometer (HRMS), NMR, and electronic circular dichroism (ECD) calculations. The growth inhibitory activities of compounds <bold>1</bold> and <bold>2</bold> were evaluated against four bacteria and six plant-pathogenic fungi. Compound <bold>1</bold> showed the highest antifungal activity against <italic>Botrytis cinerea</italic> and <italic>Fusarium oxysporum</italic> f. sp. <italic>nicotianae</italic> with MIC of 8 μg/ml. To the best of our knowledge, this is the first study to report on the application of the global regulator in <italic>T. afroharzianum</italic> to activate the biosynthesis of bioactive secondary metabolites.</p>