Plants lie at the heart of many potential solutions to the climate crisis. Yet, it can take years to breed plants with new, useful features. Synthetic biology could expedite the development of diverse climate-resilient crops through precise manipulation of gene expression across cell types and environments. This level of control is essential for improving complex traits, like yield and resilience, which are often determined by cell- and developmental stage-specific gene activities. We use synthetic genetic circuits to enable precise gene expression control across cell types and tissues in plants. These genetic circuits enable patterns of gene expression across cell types and developmental stages that would be difficult or impossible to achieve with native promoters. Our ultimate goal is to apply genetic circuits to engineer the size and shape of plant roots to better understand their contribution to environmental stress tolerance. A better understanding of the root features that are important for environmental stress tolerance should enable targeted breeding and biotechnological interventions that improve agricultural sustainability.