Figure 3. Identification of the gene of a vacuolar aluminum transporter.

(A) Al tolerance assay of Δhsp150 yeast cells that were transformed with the candidate genes Al1–6. Each cell was grown on 2 mM Al₂(SO₄)₃ at pH 3.5. The time course of growth of each transformant was measured by OD₆₀₀ for 2 d. (B) The intracellular Al content of the Al2-transformed Δhsp150 yeast cells. The cells were exposed to different concentrations of Al₂(SO₄)₃ at pH 3.5 for 2 d. The Al content of cells that carried Al2 significantly increased with the increasing Al concentration in the medium (*P<0.05 by Student's t test). The error bars represent SE (n = 3). (C) Subcellular localization of HmVALT(Al2). HmVALT(Al2)-mCherry and γTIP-GFP, which was used as a control, were simultaneously introduced into onion epidermal cells by particle bombardment. The merged image shows that HmVALT is localized to the tonoplast. Scale bar = 50 µm.