Arabidopsis thaliana Root Surface Chemistry Regulates in Planta Biofilm Formation of Bacillus subtilis

Abstract

Among the various rhizospheric interactions, plant root-microbe interactions are very important both economically and ecologically. The interaction of plant roots with plant growth promoting rhizobacteria (PGPR) have been studied in case of symbiotic organisms. However, the knowledge on interaction with other PGPRs such as biocontrol Bacillus sps. is vastly unexplored. Especially the complex root surface chemistry and its effect on modulating the bacterial growth and association with the root system has not been investigated. Recently, by adopting a systematic stepwise experimental approach we unraveled the importance of root plane chemistry on the colonization and biofilm formation by B. subtilis, an important biocontrol-PGPR. This study may further increase our understanding in the field of rhizosphere biology and area of root secretions and their possible role in plant microbe interactions.

Keywords: PGPR; biofilm; catechol and ROS.

Figure 1

Confocal microscopy images of Arabidopsis roots co-cultivated with B. subtilis strain FB-17 showing dense biofilm formation on the surface of Col-0, cpr6-1, etr1-1, jar1-1, ein4-1, less biofilm formation on cpr1-1 pad4-1, eds1-1, npr1-1, npr/ndr double mutant compared to the NahG roots.