Premium
Activation of biosynthetic gene clusters by the global transcriptional regulator TRI6 in Fusarium graminearum
Author(s) -
Shostak Kristina,
Bonner Christopher,
Sproule Amanda,
Thapa Indira,
Shields Samuel W. J.,
Blackwell Barbara,
Vierula John,
Overy David,
Subramaniam Rajagopal
Publication year - 2020
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.14575
Subject(s) - biology , trichothecene , secondary metabolite , transcriptome , chromatin immunoprecipitation , transcription factor , gene cluster , gene , mutant , genetics , repressor , gene expression , fusarium , promoter
In F. graminearum , the transcription factor TRI6 positively regulates the trichothecene biosynthetic gene cluster (BGC) leading to the production of the secondary metabolite 15‐acetyl deoxynivalenol. Secondary metabolites are not essential for survival, instead, they enable the pathogen to successfully infect its host. F. graminearum has the potential to produce a diverse array of secondary metabolites (SMs). However, given high functional specificity and energetic cost, most of these clusters remain silent, unless the organism is subjected to an environment conducive to SM production. Alternatively, secondary metabolite gene clusters (SMCs) can be activated by genetically manipulating their activators or repressors. In this study, a combination of transcriptomic and metabolomics analyses with a deletion and overexpressor mutants of TRI6 was used to establish the role of TRI6 in the regulation of several BGCs in F. graminearum . Evidence for direct and indirect regulation of BGCs by TRI6 was obtained by chromatin immunoprecipitation and yeast two‐hybrid experiments. The results showed that the trichothecene genes are under direct control, while the gramillin gene cluster is indirectly controlled by TRI6 through its interaction with the pathway‐specific transcription factor GRA2.