AUTHOR=Haack Frederike S. , Poehlein Anja , Kröger Cathrin , Voigt Christian A. , Piepenbring Meike , Bode Helge B. , Daniel Rolf , Schäfer Wilhelm , Streit Wolfgang R. 

TITLE=Molecular Keys to the Janthinobacterium and Duganella spp. Interaction with the Plant Pathogen Fusarium graminearum

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01668

DOI=10.3389/fmicb.2016.01668

ISSN=1664-302X

ABSTRACT=<p><italic>Janthinobacterium</italic> and <italic>Duganella</italic> are 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 11 <italic>Janthinobacterium</italic> and <italic>Duganella</italic> isolates 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 of <italic>J.</italic> sp. HH102 or its corresponding JAI-1 synthase deletion mutant with the plant pathogen <italic>Fusarium graminearum</italic> provided first evidence of a QS-dependent interaction with this pathogen.</p>