Molecular Keys to theJanthinobacteriumandDuganellaspp. Interaction with the Plant PathogenFusarium graminearum.
JanthinobacteriumandDuganellaare well-known for their antifungal effects. Surprisingly, almost nothing is known on molecular aspects involved in the close bacterium-fungus interaction. To better understand this interaction, we established the genomes of 11JanthinobacteriumandDuganellaisolates in combination with phylogenetic and functional analyses of all publicly available genomes. Thereby, we identified a core and pan genome of 1058 and 23,628 genes. All strains encoded secondary metabolite gene clusters and chitinases, both possibly involved in fungal growth suppression. All but one strain carried a single gene cluster involved in the biosynthesis of alpha-hydroxyketone-like autoinducer molecules, designated JAI-1. Genome-wide RNA-seq studies employing the background of two isolates and the corresponding JAI-1 deficient strains identified a set of 45 QS-regulated genes in both isolates. Most regulated genes are characterized by a conserved sequence motif within the promoter region. Among the most strongly regulated genes were secondary metabolite and type VI secretion system gene clusters. Most intriguing, co-incubation studies ofJ.sp. HH102 or its corresponding JAI-1 synthase deletion mutant with the plant pathogenFusarium graminearumprovided first evidence of a QS-dependent interaction with this pathogen.
Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
Frederike S
FS
Haack
Department of Genomic and Applied Microbiology and Goettingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Germany.
Anja
A
Poehlein
Department of Molecular Phytopathology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
Cathrin
C
Kröger
Department of Phytopathology and Biochemistry, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
Christian A
CA
Voigt
Department of Mycology, Goethe University Frankfurt Frankfurt am Main, Germany.
Meike
M
Piepenbring
Merck-Stiftungsprofessur für Molekulare Biotechnologie Fachbereich Biowissenschaften and Buchmann Institute for Molecular Life Sciences, Goethe Universität Frankfurt Frankfurt am Main, Germany.
Helge B
HB
Bode
Department of Genomic and Applied Microbiology and Goettingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University Göttingen, Germany.
Rolf
R
Daniel
Department of Molecular Phytopathology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
Wilhelm
W
Schäfer
Department of Microbiology and Biotechnology, Biocenter Klein Flottbek, University of Hamburg Hamburg, Germany.
Wolfgang R
WR
Streit
CAI-1; Duganella; Fusarium graminearum; Janthinobacterium; bacterium-fungus interaction; quorum sensing; violacein