2.7 Microelectrode ion flux estimation (MIFE)
Al-induced net fluxes of HPO42- were
measured from elongation zone of three-day-old barley seedlings using
MIFE (Chen et al., 2007). LIX for
HPO42- was prepared using
N,N-Bis(salicylidene)-o-phenylenediamine vanadium (IV) oxide complex
(Sigma, Switzerland) as
ionophore
according to
Ganjali,
Mizani, & Salavati-Niasari (2003). The seedling was transferred to a
5-ml Perspex measuring chamber with 2.5 ml MIFE basal solution (500 μM
KCl, 100 μM CaCl2, pH 4.3), one hour prior to flux
measurement. Net ion flux measurement commenced in the basal solution for
10 min and followed by 30 min in 25
μM
Al3+ treatment by adding 2.5 ml treatment solution (50
μM AlCl3, 500 μM KCl, 100 μM CaCl2, pH
4.3). The average flux in control (0-10 min), transient (11 to 15 min)
and steady-state (30-40 min) was calculated.