Aluminium-sensitive Arabidopsis thaliana mutants als3 and als5 differ in response to acidic stress

Abstract

Plants sensitive to Al³⁺ may also be sensitive to acidity. We exposed two Arabidopsis Al³⁺ -sensitive mutants (als3 and als5) and wild type (WT) to different pH (5.5 or 4.2) with or without 0.5 mM homo PIPES buffer. Homo PIPES kept pH at starting 4.2 or 5.5 for 24 hours. Acidity decreased als3 and WT shoot biomass, whereas als5 showed acid resistance. Acidity reduced accumulation of Ca²⁺ and Mg²⁺ but not K⁺ in all genotypes. Under acidic stress als5 had higher shoot Ca²⁺ and Mg²⁺ concentrations than WT, which might be responsible for als5 acid resistance.