Fig. 2.
Impact of SnRK1α1 subcellular localization on TOR signaling and root growth. (A and B, Upper) Representative immunoblots of RPS6S240 phosphorylation (phospho-RPS6/total-RPS6) in Col-0 (A) or control-α1 and NLS-α1 (B) seedlings treated with or without ABA (50 µM, 3 h) or LMB (2.5 µM, 3 h or 1 h prior to ABA addition). Ponceau-S staining serves as loading control. Same gel images were cropped for showing α1 and NLS-α1 contiguously. (A and B, Lower) Phospho-RPS6/total-RPS6 quantification. (A) n = 5 or 6; (B) n = 3; error bars, SEM; two-tailed Student t test. (C) Under favorable conditions, SnRK1α1 is sequestered in the nucleus by complexes containing SnRK2 [and a PP2C (3)], enabling TOR activity in the cytoplasm, cell proliferation, and root growth. Dissociation of these complexes by ABA-bound PYR/PYL/RCAR receptors releases SnRK1α1, which exits the nucleus and inhibits TOR and growth. TORC1, TOR Complex 1; N, nucleus; C, cytoplasm; ns, nonsignificant. Created with BioRender.com.