title: Tight control of mycotoxin biosynthesis gene expression in Aspergillus flavus by temperature as revealed by RNA-Seq.
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 1153 genes that were differentially expressed at 30 and 37 °C. Eleven of the 55 secondary metabolite clusters were upregulated at the lower temperature, including aflatoxin biosynthesis genes, which were among the most highly upexpressed genes. On average, transcript abundance for the 30 aflatoxin biosynthesis genes was 3300 times greater at 30 °C as compared with 37 °C. 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.
authors.affiliation: Southern Regional Research Center, Agricultural Research Service-ARS, US Department of Agriculture-USDA, New Orleans, LA 70124, USA. jiujiang.yu@ars.usda.gov
authors.forename: Jiujiang
authors.initials: J
authors.lastname: Yu
authors.forename: Natalie D
authors.initials: ND
authors.lastname: Fedorova
authors.forename: Beverly G
authors.initials: BG
authors.lastname: Montalbano
authors.forename: Deepak
authors.initials: D
authors.lastname: Bhatnagar
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Cleveland
authors.forename: Joan W
authors.initials: JW
authors.lastname: Bennett
authors.forename: William C
authors.initials: WC
authors.lastname: Nierman
mesh_terms: D000348:Aflatoxins / Q000096:biosynthesis* / Q000235:genetics; D001231:Aspergillus flavus / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D007211:Indoles / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D012331:RNA, Fungal; D017423:Sequence Analysis, RNA; D013696:Temperature
chemical_list: D000348:Aflatoxins; D007211:Indoles; D012331:RNA, Fungal; C000543:cyclopiazonic acid