Optimizing plant growth in suboptimal environments: Deciphering the TOR-mediated root plasticity

Optimal growth is essential for maximizing plant productivity. To achieve high levels of productivity, plants must demonstrate resilience to mitigate stress signals and efficiently uptake and assimilate nutrients. The plant root, as the primary interface in contact with soil stimuli and also the key organ for nutrient consumption, has evolved mechanisms to balance nutrient signaling, stress response, and developmental cues. Root function is significantly influenced by its architecture layout, known as root system architecture (RSA), which is determined by primary roots, lateral roots, and root hairs. Understanding how plants modulate their RSA while managing a wide range of nutrient signals under suboptimal conditions will aid in the development of climate-resilient crops. Emerging evidence suggests that target of rapamycin (TOR) signaling plays a crucial role in RSA in response to environmental cues. Recently, Morles-Herrera et al. reviewed that TOR, SUCROSE-NON-FERMETING-1-RELATED PROTEIN KINASE (SnRK1), and trehalose-6-phosphate (T6P) signaling jointly integrate nutritional signals to shape RSA.1 In this commentary, we emphasize the mechanisms through which plants employ TOR signaling to integrate stress responses and developmental programs, thereby enabling optional root growth.