Accumulation and translocation of sulphate in excised maize roots as affected by different saline concentrations in the outer medium

Abstract

Abstract Accumulation and translocation of sulphate in excised maize roots, submerged in rising saline concentrations, were investigated. It was shown that the accumulation of sulphate is not depressed by concentrations from 1 to 50 mM of NaCl or KCl, it is weakly increased by concentrations of the same salts 100 mM and it is gradually lowered by concentrations from 1 to 100 mM of MgCl2. On the contrary the translocation is gradually inhibited by rising concentrations of NaCl, KCl and MgCl2. A 100 mM NaCl concentration considerably loweres the translocation in 24 hours, but does not affect accumulation. Accumulation and translocation are strongly depressed by the inhibitors of oxydative phosphorylation (2,4 DNP or CCCP) and by 200 mM NaCl, KCl or MgCl2 concentrations. It is concluded that accumulation and translocation are active processes as they are reduced by 2,4 DNP or CCCP; that the small increase in accumulation observed by 100 mM NaCl or KCl concentration is due probably to the discharging action o...