The Putative Histone Methyltransferase DOT1 Regulates Aflatoxin and Pathogenicity Attributes in Aspergillus flavus.

Linlin Liang,Guinan Lin,Kunlong Yang,Huahui Lan,Yinghang Liu,Zhangling Xu,Shihua Wang,Xiuna Wang

doi:10.3390/toxins9070232

Abstract

Lysine methyltransferases transfer methyl groups in specific lysine sites, which regulates a variety of important biological processes in eukaryotes. In this study, we characterized a novel homolog of the yeast methyltransferase DOT1 in A. flavus, and observed the roles of dot1 in A. flavus. Deletion of dot1 showed a significant decrease in conidiation, but an increase in sclerotia formation. A change in viability to multiple stresses was also found in the Δdot1 mutant. Additionally, aflatoxin (AF) production was found severely impaired in the Δdot1 mutant. Further analysis by qRT-PCR revealed that the transcription of AF structural genes and their regulator gene aflS were prominently suppressed in the Δdot1 mutant. Furthermore, our data revealed that Dot1 is important for colonizing maize seeds in A. flavus. Our research indicates that Dot1 is involved in fungal development, aflatoxin biosynthesis and fungal virulence in A. flavus, which might provide a potential target for controlling A. flavus with new strategies.

Highlights

The ubiquitous fungus A. flavus is notorious for its contamination of many foodstuffs and important crops, such as maize, peanuts and rice, during pre- or post-harvest with the most carcinogenic mycotoxin, aflatoxin [1,2,3]
Dot1 contributes to radical growth levels of these two conidia specifie genes were both down-regulated in the ∆dot1 mutant. These results demonstrate that Dot1 contributes to radical growth and conidiation in A. flavus
We found that disruption of the H3K79 methyltransferase gene dot1 reduced A. flavus conidiation through down-regulating the transcriptional levels of the key transcription factors BrlA

Summary

Introduction

The ubiquitous fungus A. flavus is notorious for its contamination of many foodstuffs and important crops, such as maize, peanuts and rice, during pre- or post-harvest with the most carcinogenic mycotoxin, aflatoxin [1,2,3]. This fungus is known as the second most frequent. Aspergillus pathogen after A. fumigatus on immunosuppressed patients, which is responsible for aspergillosis diseases or liver cancer for human and animals caused by the consumption of contaminated food [1,2,4] Due to this, this fungus has caused enormous agricultural economic losses, food shortages and health problems all cross the world [1,5].

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