Extended Data Fig. 1: Maintenance of root tip homeostasis.
From: TOP1α fine-tunes TOR-PLT2 to maintain root tip homeostasis in response to sugars
a, Cartoon depicting a longitudinal section of a wild type (WT) Arabidopsis root tip. QC: quiescent center; CSC: columella stem cell; PM: proximal root meristem; DM: distal root meristem; COL: columella; S1-S4: columella layers 1–4. b, Morphological observation of seedlings grown under the indicated treatments. Seedlings were grown on sugar-free medium for 5 days in the dark, transferred to different conditions, and grown for 3 more days. Scale bar: 5 mm. c, Examination of cell division in the RAMs of pCYCB1;1::GUS plants under the indicated treatments. Scale bar: 100 µm. d, f, Quantification of PM and COL size in WT plants grown under the indicated conditions. Data were analyzed from 15 seedlings for each treatment from 3 experiments. Statistical significance was determined by one-way ANOVA and Tukey test (P < 0.05) (see Supplementary Data 1 for specific P values) (d) or by Student’s t-test (two-tailed) (f) and are expressed as mean ± s.d. e, DM and CC homeostasis is maintained during the skotomorphogenesis-to-photomorphogenesis transition. The seedlings described in (b) harboring the QC marker pWOX5::GFP were selected for structural observation of the root tip. Arrows mark the CSC layer; lines mark the columella story (S). Scale bar: 50 µm.
