Fig. 1
Structures of celery collenchyma cells at different developmental stages from petioles of different length. a Isolated collenchyma strands at developmental Stage 1 (2.8 cm long petiole), Stage 2 (12 cm petiole), Stage 3 (23 cm petiole), Stage 4 (38 cm petiole). Stained with 0.1% (w/v) aqueous toluidine blue, and color was adjusted to grey from original blue to better show the cell boundary. Scale bar= 50 μm. b Average collenchyma cell width (
) and length (
) at different developmental stages (n ≥180 cells per Stage). Stage 1-4, from 2-5 cm, 10-15 cm, 20-25 cm and 35-40 cm long petioles, respectively. c The average maximum wall thickness of collenchyma cells (n ≥ 30 per stage) at different developmental stages. Measurements were made on dehydrated cell walls. Stage 1-4, from 3 cm, 13 cm, 23 cm, 39 cm long petioles. d The elongation of petioles from three different plants (A, B and C) of “Triple 8” celery at a late stage of development. The ellipse highlighted the time when the petioles stopped elongating. Different symbols indicate different petioles. e The width (
) and length (
) of collenchyma cells from petioles before and after petioles stopped elongating. (n ≥ 45). f The average maximum (
) and minimum (
) wall thickness of collenchyma cells (n ≥ 45) from celery petioles before and after petioles stopped elongating. Different letters a, b, c, d indicate significant difference (P <0.05). The error bars indicate the standard deviation