Aluminium Accumulation Potential of Alstonia scholaris

Abstract

Aluminium toxicity commonly affects plants and considerably reduces crop production. However, some plants, particularly tropical trees, have adapted to high aluminium concentrations by using strategies such as aluminium accumulation. The present study is the first report of aluminium hyperaccumulation in Alstonia scholaris, which is a common tree in Mumbai. Aluminium was accidently detected in the inflorescence tissue of A. scholaris. Volumetric analysis and atomic absorption spectrometry revealed that the aluminium concentration exceeded 1000 μg/g (dry weight). Notably, aluminium appeared to be stored in the fresh inflorescence stalks but not in the flowers. The aluminium concentration in the stalks determined through volumetric analysis was 10689.7±846.8 μg/g dry weight. Furthermore, the aluminium concentration in oven-dried stalks determined through atomic absorption spectrometry was 4080.36±11.60 μg/g. Because A. scholaris accumulates aluminium in its aerial parts at a concentration exceeding 1000 ppm, it can be considered a hyperaccumulator of aluminium. The high concentration of organic acids in the flowers indicated the possible role of organic acids in compartmentalization or sequestration of aluminium in the inflorescence stalks. Investigating the molecular and genetic basis of the mechanism(s) underlying aluminium sequestration in A. scholaris can provide important information for the development of crop varieties that are minimally affected by aluminium toxicity.