Nutrient computation for root architecture

Nitrogen is a major limiting nutrient for plants. Root systems acquire nitrogen through uptake of nutrients such as nitrate from the soil. Some plants can also obtain nitrogen by establishing a root nodule symbiosis with N-fixing bacteria. Whatever the means to acquire nutrients, an investment of the plant is required in which root architecture is suitably adapted. Therefore, plants integrate local and global nutrient cues to spend resources efficiently. On page 343 in this issue, Tabata et al. (1) identify a peptide signaling mechanism by which the root locally senses N limitation in the soil, and communicates with the shoot, which then signals back to the root to stimulate lateral root growth in regions with a high nitrate content to facilitate nitrate uptake