Pectic homogalacturonan sensed by Bacillus acts as host associated cue to promote establishment and persistence in the rhizosphere
Farah Boubsi,
Grégory Hoff,
Anthony Arguelles Arias,
Sébastien Steels,
Sofija Andrić,
Adrien Anckaert,
Romain Roulard,
Augustin Rigolet,
Olivier van Wuytswinkel,
Marc Ongena
Affiliations
Farah Boubsi
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium; Corresponding author
Grégory Hoff
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
Anthony Arguelles Arias
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
Sébastien Steels
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
Sofija Andrić
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
Adrien Anckaert
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
Romain Roulard
UMRT INRAe 1158 Plant Biology and Innovation, University of Picardie Jules Verne, UFR des Sciences, 80039 Amiens, France
Augustin Rigolet
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium
Olivier van Wuytswinkel
UMRT INRAe 1158 Plant Biology and Innovation, University of Picardie Jules Verne, UFR des Sciences, 80039 Amiens, France
Marc Ongena
Microbial Processes and Interactions, TERRA Teaching and Research Center, University of Liège - Gembloux Agro-Bio Tech, 5030 Gembloux, Belgium; Corresponding author
Summary: Bacillus velezensis isolates are among the most promising plant-associated beneficial bacteria used as biocontrol agents. However, various aspects of the chemical communication between the plant and these beneficials, determining root colonization ability, remain poorly described. Here we investigated the molecular basis of such interkingdom interaction occurring upon contact between Bacillus velezensis and its host via the sensing of pectin backbone homogalacturonan (HG). We showed that B. velezensis stimulates key developmental traits via a dynamic process involving two conserved pectinolytic enzymes. This response integrates transcriptional changes leading to the switch from planktonic to sessile cells, a strong increase in biofilm formation, and an accelerated sporulation dynamics while conserving the potential to efficiently produce specialized secondary metabolites. As a whole, we anticipate that this response of Bacillus to cell wall–derived host cues contributes to its establishment and persistence in the competitive rhizosphere niche and ipso facto to its activity as biocontrol agent.