A pivotal role of glucose-TOR signaling in root hair formation. A, rapamycin inhibition of glucose-mediated root hair growth. Seedlings were germinated with or without glucose (30 mm) for 4 days. Rapamycin (Rap, 10 μm). B, enhancing the rapamycin inhibition effect on root hair formation by overexpressing Arabidopsis or human FKP12. Seedlings were germinated with 30 mm glucose for 4 days. C, retardation of root hair growth in tor mutants. Seedlings were germinated with 30 mm glucose for 4 days. Scale bar, 500 μm.