b and c. Representation and quantification of cell length in epidermal (e) and cortical (c) cell files. Optical, longitudinal sections of 5 DAG eir1-4 roots 12 HAT to ammonium (B) or nitrate (C) supplemented media. The first 20-20 epidermal and cortex cells (from quiescent center (QC)) are highlighted in grey and in red on ammonium (B) and in blue and green on nitrate (C), respectively. Scale bar=30 µm. Column bars denote the geometric mean of cell length at the respective positions. Lines represent a polynomial regression fit, with calculated slopes between cells 10 and 20 of 0.75884+0.02624 (ammonium, epidermis), 1.13088+0.08446 (ammonium, cortex) and 2.06912+0.10341 (nitrate, epidermis), 0.99878+0.07278 (nitrate, cortex). Data are derived from 3 biological replicates, n=9 (ammonium) and 8 (nitrate) roots. 