title: The AreA transcription factor mediates the regulation of deoxynivalenol (DON) synthesis by ammonium and cyclic adenosine monophosphate (cAMP) signalling in Fusarium graminearum.
abstract: Deoxynivalenol (DON), a trichothecene mycotoxin produced by Fusarium graminearum, is harmful to humans and animals. Because different nitrogen sources are known to have opposite effects on DON production, in this study, we characterized the regulatory mechanisms of the AREA transcription factor in trichothecene biosynthesis. The ΔareA mutant showed significantly reduced vegetative growth and DON production in cultures inoculated with hyphae. Suppression of TRI gene expression and DON production by ammonium were diminished in the ΔareA mutant. The deletion of AREA also affected the stimulatory effects of arginine on DON biosynthesis. The AreA-green fluorescent protein (GFP) fusion complemented the ΔareA mutant, and its localization to the nucleus was enhanced under nitrogen starvation conditions. Site-directed mutagenesis showed that the conserved predicted protein kinase A (PKA) phosphorylation site S874 was important for AreA function, indicating that AreA may be a downstream target of the cyclic adenosine monophosphate (cAMP)-PKA pathway, which is known to regulate DON production. We also showed that AreA interacted with Tri10 in co-immunoprecipitation assays. The interaction of AreA with Tri10 is probably related to its role in the regulation of TRI gene expression. Interestingly, the ΔareA mutant showed significantly reduced PKA activity and expression of all three predicted ammonium permease (MEP) genes, in particular MEP1, under low ammonium conditions. Taken together, our results show that AREA is involved in the regulation of DON production by ammonium suppression and the cAMP-PKA pathway. The AreA transcription factor may interact with Tri10 and control the expression and up-regulation of MEP genes.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest Agricultural and Forestry University, Yangling, Shaanxi, 712100, China.|Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest Agricultural and Forestry University, Yangling, Shaanxi, 712100, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest Agricultural and Forestry University, Yangling, Shaanxi, 712100, China.|Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest Agricultural and Forestry University, Yangling, Shaanxi, 712100, China.
authors.forename: Chenfang
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest Agricultural and Forestry University, Yangling, Shaanxi, 712100, China.|Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Jin-Rong
authors.initials: JR
authors.lastname: Xu
mesh_terms: D064751:Ammonium Compounds / Q000378:metabolism; D001120:Arginine / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D005670:Fusarium / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D026901:Membrane Transport Proteins / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D014255:Trichothecenes / Q000096:biosynthesis* / Q000235:genetics; D015854:Up-Regulation
chemical_list: D064751:Ammonium Compounds; D005656:Fungal Proteins; D026901:Membrane Transport Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D014255:Trichothecenes; D001120:Arginine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C007262:deoxynivalenol; D009584:Nitrogen
keywords: DON production; Gibberella zeae; TRI6 expression; ammonium suppression; nitrogen metabolism