Molecular and functional evolution of the fungal diterpene synthase genes.
BACKGROUND
Terpenes represent one of the largest and most diversified families of natural compounds and are used in numerous industrial applications. Terpene synthase (TPS) genes originated in bacteria as diterpene synthase (di-TPS) genes. They are also found in plant and fungal genomes. The recent availability of a large number of fungal genomes represents an opportunity to investigate how genes involved in diterpene synthesis were acquired by fungi, and to assess the consequences of this process on the fungal metabolism.


RESULTS
In order to investigate the origin of fungal di-TPS, we implemented a search for potential fungal di-TPS genes and identified their presence in several unrelated Ascomycota and Basidiomycota species. The fungal di-TPS phylogenetic tree is function-related but is not associated with the phylogeny based on housekeeping genes. The lack of agreement between fungal and di-TPS-based phylogenies suggests the presence of Horizontal Gene Transfer (HGTs) events. Further evidence for HGT was provided by conservation of synteny of di-TPS and neighbouring genes in distantly related fungi.


CONCLUSIONS
The results obtained here suggest that fungal di-TPSs originated from an ancient HGT event of a single di-TPS gene from a plant to a fungus in Ascomycota. In fungi, these di-TPSs allowed for the formation of clusters consisting in di-TPS, GGPPS and P450 genes to create functional clusters that were transferred between fungal species, producing diterpenes acting as hormones or toxins, thus affecting fungal development and pathogenicity.
Université de Strasbourg, INRA, Inst Natl Recherche Agron, Métab Second Vigne, Unit Mixte Recherche Santé Vigne & Qual Vins, 28 rue de Herrlisheim, F-68021, Colmar, France. marc.fischer@unistra.fr.
Marc J C
MJ
Fischer
Université de Strasbourg, INRA, Inst Natl Recherche Agron, Métab Second Vigne, Unit Mixte Recherche Santé Vigne & Qual Vins, 28 rue de Herrlisheim, F-68021, Colmar, France. camille.rustenholz@colmar.inra.fr.
Camille
C
Rustenhloz
Université de Strasbourg, CNRS, FRE 2326, Institut de Biologie Moléculaire et Cellulaire du CNRS, UPR 9002, 15 rue René Descartes, F-67084, Strasbourg, France. vleh@unistra.fr.
Véronique
V
Leh-Louis
Universite Claude Bernard - Lyon 1, 43 bd. du 11 Novembre 1918, Laboratoire de Biometrie et Biologie Evolutive, UMR CNRS 5558, F-69622, Villeurbanne, France. guy.perriere@univ-lyon1.fr.
Guy
G
Perrière
D001203:Ascomycota / Q000235:genetics* / Q000378:metabolism*; D001487:Basidiomycota / Q000235:genetics* / Q000378:metabolism*; D004224:Diterpenes / Q000378:metabolism*; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D005800:Genes, Fungal; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
D004224:Diterpenes