Early effects of aluminium on nutrient (K, Ca, and Mg) status of different root zones of two rice cultivars

Abstract

Effects of aluminium on nutrient (K, Ca, and Mg) status of different root zones were evaluated in two rice cultivars with high (IR45) and low (BG35) Al sensitivity. Roots of the two cultivars were exposed to 140 µM AlCl 3 at pH 4.1 for 24 h. The Al accumulation in IR45 was higher than in BG35 in all the root zones. The uptake of Al in apex and middle-root zone was higher than in the basal zone of both cultivars. The enhanced Al uptake in root apical and middle zones of IR45 induced drastical changes in Ca and Mg concentrations. As these changes occurred without any Al-growth inhibition, it is suggested that disturbances of these nutrients are the primary lesion of Al in IR45. The results further indicated that competitive interactions between Al and Mg in the Al-sensitive cultivar have an important role for Al tolerance in rice plants.