Chemical ecology: Bacteria-fungi interaction for plant biocontrol.

Secondary metabolites mediate a broad variety of interactions between bacteria and fungi. Testing two plant growth-promoting microorganisms, a rhizobacterium and an arbuscular mycorrhizal fungus, a new study reveals their chemical interaction and an enhanced systemic induction of plant immunity.

Plant cell wall component induced bacterial development.

Plant-microbiome functioning depends on intricate signaling pathways including plant-derived excretions that induce microbial gene expression. Marc Ongena and his team (Boubsi et al.) dissect how the pectin backbone homogalacturonan promotes bacterial differentiation programs of Bacillus velezensis, potentially facilitating its establishment in the rhizosphere.

Plant-microbe interactions: Plant-exuded myo-inositol attracts specific bacterial taxa.

Plants exude a plethora of metabolites that transform the microbiome composition. Initiated from genome-wide association studies of either a plant or a bacterium, two new studies dissect the impact of plant-secreted myo-inositol on recruitment of certain bacterial taxa by Arabidopsis.

Frenemies of the soil: Bacillus and Pseudomonas interspecies interactions.

Bacillus and Pseudomonas ubiquitously occur in natural environments and are two of the most intensively studied bacterial genera in the soil. They are often coisolated from environmental samples, and as a result, several studies have experimentally cocultured bacilli and pseudomonads to obtain emergent properties. Even so, the general interaction between members of these genera is virtually unknown.