title: Conservation and divergence of the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway in two plant-pathogenic fungi: Fusarium graminearum and F. verticillioides.
abstract: The cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) pathway is a central signalling cascade that transmits extracellular stimuli and governs cell responses through the second messenger cAMP. The importance of cAMP signalling in fungal biology has been well documented and the key conserved components, adenylate cyclase (AC) and the catalytic subunit of PKA (CPKA), have been functionally characterized. However, other genes involved in this signalling pathway and their regulation are not well understood in filamentous fungi. Here, we performed a comparative transcriptomics analysis of AC and CPKA mutants in two closely related fungi: Fusarium graminearum (Fg) and F. verticillioides (Fv). Combining available Fg transcriptomics and phenomics data, we reconstructed the Fg cAMP signalling pathway. We developed a computational program that combines sequence conservation and patterns of orthologous gene expression to facilitate global transcriptomics comparisons between different organisms. We observed highly correlated expression patterns for most orthologues (80%) between Fg and Fv. We also identified a subset of 482 (6%) diverged orthologues, whose expression under all conditions was at least 50% higher in one genome than in the other. This enabled us to dissect the conserved and unique portions of the cAMP-PKA pathway. Although the conserved portions controlled essential functions, such as metabolism, the cell cycle, chromatin remodelling and the oxidative stress response, the diverged portions had species-specific roles, such as the production and detoxification of secondary metabolites unique to each species. The evolution of the cAMP-PKA signalling pathway seems to have contributed directly to fungal divergence and niche adaptation.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.affiliation: USDA-ARS, Cereal Disease Laboratory, University of Minnesota, St Paul, MN, 55108, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Breakspear
authors.affiliation: Department of Electrical & Computer Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
authors.forename: Guoyi
authors.initials: G
authors.lastname: Zhao
authors.affiliation: Department of Electrical & Computer Engineering, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
authors.forename: Lixin
authors.initials: L
authors.lastname: Gao
authors.affiliation: USDA-ARS, Cereal Disease Laboratory, University of Minnesota, St Paul, MN, 55108, USA.
authors.forename: H Corby
authors.initials: HC
authors.lastname: Kistler
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
authors.forename: Jin-Rong
authors.initials: JR
authors.lastname: Xu
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts Amherst, Amherst, MA, 01003, USA.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Ma
mesh_terms: D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D005670:Fusarium / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010944:Plants / Q000382:microbiology*; D015398:Signal Transduction / Q000235:genetics*
chemical_list: D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases
keywords: Fusarium; PKA; cAMP; cell signalling; orthologous; speciation; transcriptome