This research explores how the spatial structure of the root microbial community is determined by the plant. The authors discovered that localized leaks of the amino acid glutamine are a key factor driving bacterial attraction and colonization at specific root sites. These leaks occur where the endodermal cell barrier, known as the Casparian strip, is absent or compromised, creating metabolic niches favorable to bacterial proliferation. Ultimately, the integrity of this root barrier is essential to limit nutrient supply and maintain a balanced root microbiome, thereby preventing bacterial overgrowth and chronic activation of the plant’s immune responses.

Source: https://www.science.org/doi/10.1126/science.adu4235