Surfactin variants mediate species-specific biofilm formation and root colonization in Bacillus.
Cyclic lipopeptides (cLP) and especially surfactins produced by Bacillus spp. trigger biofilm formation and root colonization and are crucial for biocontrol activity and systemic resistance in plants. Bacillus atrophaeus 176s isolated from the moss Tortella tortuosa produces the cLP fengycins, iturins and surfactins, possesses antifungal activities and can protect tomato, lettuce and sugar beet against Rhizoctonia solani infection. In B. atrophaeus we identified for the first time the variant surfactin C, which differs from surfactin A produced by B. subtilis and B. amyloliquefaciens by an isoleucine instead of a leucine at position 7 of the lipopeptide backbone. The analysis of the complete surfactin gene clusters revealed that the dissimilarity is encoded in the adenylation domain of srfC and show that surfactin variations are distributed in a species-specific manner in bacilli. We demonstrate that the surfactin A and C with subtle structural differences have varying signal strengths on biofilm formation and root colonization and act specifically on the respective producing strain. This became evident as biofilm formation and root colonization but not swarming motility in surfactin biosynthesis mutants was restored differentially in the presence of exogenously supplemented cognate and non-cognate surfactin variants.
Health & Environment Department, Bioresources Unit, AIT Austrian Institute of Technology GmbH, AIT, Konrad Lorenz Strasse 24, Tulln, A-3430, Austria.
Gajender
G
Aleti
Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU), Konrad-Lorenz-Str. 20, 3430 Tulln, Austria.
Sylvia
S
Lehner
Department of Chemistry, University of Natural Resources and Life Sciences (BOKU), UFT Research Center Tulln, Konrad-Lorenz-Str. 24, Tulln, A-3430, Austria.
Markus
M
Bacher
Health & Environment Department, Bioresources Unit, AIT Austrian Institute of Technology GmbH, AIT, Konrad Lorenz Strasse 24, Tulln, A-3430, Austria.
Stéphane
S
Compant
Health & Environment Department, Bioresources Unit, AIT Austrian Institute of Technology GmbH, AIT, Konrad Lorenz Strasse 24, Tulln, A-3430, Austria.
Branislav
B
Nikolic
Health & Environment Department, Bioresources Unit, AIT Austrian Institute of Technology GmbH, AIT, Konrad Lorenz Strasse 24, Tulln, A-3430, Austria.
Maja
M
Plesko
Department of Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU), Konrad-Lorenz-Str. 20, 3430 Tulln, Austria.
Rainer
R
Schuhmacher
Health & Environment Department, Bioresources Unit, AIT Austrian Institute of Technology GmbH, AIT, Konrad Lorenz Strasse 24, Tulln, A-3430, Austria.
Angela
A
Sessitsch
Health & Environment Department, Bioresources Unit, AIT Austrian Institute of Technology GmbH, AIT, Konrad Lorenz Strasse 24, Tulln, A-3430, Austria.
Günter
G
Brader
D000818:Animals; D000935:Antifungal Agents / Q000378:metabolism*; D001407:Bacillus / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D055666:Lipopeptides / Q000235:genetics / Q000378:metabolism*; D010456:Peptides, Cyclic / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D012232:Rhizoctonia / Q000254:growth & development*
D000935:Antifungal Agents; D055666:Lipopeptides; D010456:Peptides, Cyclic; C049972:fengycin; C009365:surfactin peptide