Plant, Cell and Environment 26: 661-671 (2003)

Calcium requirement for ethylene-dependent responses involving 1-aminocyclopropane-1-carboxylic acid oxidase in radicle tissues of germinated pea seeds

Figure 5.  Effects of calcium antagonists on root hair formation and elongation growth of ethylene-treated germinated pea seeds. 48-h imbibed pea seeds were preincubated for 2 h in presence or absence of the calcium antagonists followed by a further incubation for 8 h with exposure to 30 µl/l ethylene in presence or absence of the calcium antagonists. The cell differentiation zone (dz) where the root hairs normally form, the cell elongation zone (ez) where ethylene-induced ectopic root hairs form and the root tip (rt) are indicated. Estimations for the relative root hair amount ('+' = control radicle dz amount, '++' and '+++' = increased amount, '(+)' = slightly decreased amount, '-' = absence of root hairs) and length are presented in the right part of the figure.

(A) Control radicle without ethylene treatment; Note that root hairs are present in the dz, but not in ez, and are only visible in the 8 h-incubated radicles at higher magnification.
(B) Ethylene-treated radicle with ectopic root hair formation.
(C) Ethylene plus 300 µl/l NBD (2,5-norbornadiene).
(D) 10 mM CaCl2 without ethylene treatment.
(E) Ethylene plus 10 mM CaCl2.
(F) Ethylene plus 1 mM LaCl3.
(G) Ethylene plus 50 µM RR.
(H) Ethylene plus 50 mM LiCl.
(I) Ethylene plus 50 mM LiCl plus 10 mM CaCl2.