Soil Biology seminars

Jennifer Brophy presents two methods for programming when and where genes are expressed in plants and their associated microbes. One creates a chemical signal using the noncanonical amino acid O-methyl-L-tyrosine. Engineered Arabidopsis, tomato and poplar produce the signal, while engineered Bacillus subtilis and soil bacteria respond by activating gene expression. Restricting signal production to selected plant tissues allows local control of microbial activity. The second approach builds a genetic circuit that counts successive branching events in roots. It produces different expression patterns at different branch orders, helping researchers distinguish the contributions of roots that otherwise have similar molecular identities. Together, the approaches support experiments on plant development and the engineering of plant–microbe partnerships.

Agriculture and urban development threaten soil processes that sustain biodiversity, nutrient cycling, water regulation and climate resilience. The seminar examines how ecosystem-based interventions can restore soils, and why soil health must itself be built into the design of those interventions. Examples from the SOLU-BIOD research programme in France and abroad connect ecological restoration with food and water security. The discussion also considers practical barriers to adoption and the public policies needed to support implementation.