ARS | Publication request: Tight control of mycotoxin biosynthesis gene expression in Aspergillus flavus by temperature as revealed by RNA-seq

Submitted to: FEMS Microbiology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 20, 2011
Publication Date: July 14, 2011
Citation: Yu, J., Fedorova, N.D., Montalbano, B.G., Bhatnagar, D., Cleveland, T.E., Bennett, J.W., Nierman, W.C. 2011. Tight control of mycotoxin biosynthesis gene expression in Aspergillus flavus by temperature as revealed by RNA-seq. FEMS Microbiology Letters. 322:145-149.

Interpretive Summary: Aspergillus flavus produces aflatoxins, which are toxic and cancer–inducing natural compounds. The mechanisms that regulate aflatoxin production are not well understood. Employing the RNA-Seq technology, we sequenced out all of the genes that are expressed under aflatoxin-producing tecmperature (30C) and non-aflatoxin producing temperature (37C). By comparing the differences of the genes expressed, we are able to identify those genes that are responsible for aflatoxin formation and possible regulation. This information could be used to define strategies to control aflatoxin contamination of agricultural crops.

Technical Abstract: To better understand the effect of temperature on mycotoxin biosynthesis, RNA-Seq technology was used to profile the Aspergillus flavus transcriptome under different temperature conditions. This approach allowed us to quantify transcript abundance for over 80% of fungal genes including 1,153 genes that were differentially expressed at 30°C and 37°C. Eleven of the 55 secondary metabolite clusters were up-regulated at the lower temperature. The results are consistent with the view that high temperature negatively affects aflatoxin production by turning down transcription of the two key transcriptional regulators, aflR and aflS. Subtle changes in the expression levels of aflS to aflR appear to control transcription activation of the aflatoxin cluster.