Hidden dialogues unveiled: visualization of plant root-microbe interactions

Roots are the “the hidden half” of plants, buried in a complicated soil environment in which they are exposed to a large variety of microbes. Root-associated bacterial communities profoundly influence root development, plant health, and can confer resilience against a range of biotic and abiotic stresses. The root system must therefore be able to perceive, attract and accommodate microorganisms and adapt its growth and physiology to the physical environment it encounters. Conventional bulk RNA-seq/16S sequencing averages data across entire roots over extended periods, obscuring spatial complexity and hindering mechanistic understanding of root-bacterial interplay.
In this presentation I aim to elucidate how root-microbe interactions have evolved to negotiate this tug-of-war between development and defense at the cellular resolution. Our focus will be on root immune surveillance systems and bacterial colonization dynamics, which display localized, compartmentalized patterns across distinct root zones. We found roots require both microbial molecular patterns and cell damage to mount localized antibacterial immune responses, revealing an effective way to respond appropriately to pathogens while sparing commensals. In addition, combining high-resolution live imaging with engineered plant/bacterial mutants and ultrasensitive biosensors reveals confined, transient root-bacterial interactions at unprecedented scales. Our studies provide compelling evidence that root-microbe spatiotemporal dynamics are controlled by localized immune priming and nutrient gradients, enabling plastic adaptation to soil environmental changes.