Trehalose-6-phosphate signaling regulates thermoresponsive hypocotyl growth in Arabidopsis thaliana

ABSTRACT: Growth plasticity is a key mechanism by which plants adapt to the ever-changing environmental conditions. Since growth is a high energy-demanding and irreversible process, it is expected to be regulated by the integration of endogenous energy status as well as environmental conditions. Here, we show that trehalose-6-phosphate (T6P) functions as a sugar signaling molecule that coordinates thermoresponsive hypocotyl growth with endogenous sugar availability. We found that the loss of T6P SYNTHASE 1 (TPS1) impaired high temperature-mediated hypocotyl growth. Consistently, the activity of PIF4, a positive transcription factor involved in hypocotyl growth, was compromised in the tps1 mutant. We further show that, in the tps1 mutant, a sugar signaling kinase KIN10 directly interacts with and phosphorylates PIF4, which destabilizes PIF4. T6P inhibits KIN10 activity in a GRIK-dependent manner, allowing PIF4 to promote hypocotyl growth at high temperatures. Together, our results demonstrate that T6P determines thermoresponsive growth through the KIN10-PIF4 signaling module. Such regulation of PIF4 by T6P integrates the temperature-signaling pathway with the endogenous sugar status, thus optimizing plant growth response to environmental stresses.

SUBMITTER: Geonhee Hwang 

PROVIDER: S-SCDT-EMBOR-2019-47828-T | biostudies-other |

REPOSITORIES: biostudies-other