Stress granule dynamics govern TOR reactivation and growth recovery during post-heat stress adaptation

The conserved target of rapamycin (TOR) pathway and stress granules (SGs) play crucial roles in stress adaptation and survival. However, their interplay in plants remains largely unknown. Here, we elucidate the complex relationship between TOR signaling and SG dynamics in Arabidopsis. In contrast to the positive regulatory role observed in mammals, we show that TOR signaling is dispensable for heat-induced SG formation in plants. Furthermore, heat stress induces the sequestration of TOR and its core complex components, RAPTOR1B and LST8, into SGs. TOR activity is rapidly suppressed by heat stress, independently of SG formation. In contrast, TOR reactivation following heat stress relief is dependent on the rate of SG disassembly, implicating SG recovery dynamics as a key regulator of TOR reactivation. These findings reveal a layer of TOR regulation and highlight the potential of modulating SG dynamics to orchestrate plant growth and stress adaptation.