reaching a maximum of 1.3 mg g1 DW after exposure
to the 0.8mM Al treatment. However, the Al concentration
of shoots was not affected by the Al treatment
(Fig. 3), suggesting that the translocation of Al from
roots to shoots of the tea plants was slow. Significant
decrease of Al content in shoots required 3 days of
treatment (data not shown). The strong positive correlation
(r2¼0.923) observed between the Al concentration
of the tea roots and the external Al concentration
(data not shown) suggests that Al uptake by the roots
occurs passively under highly acidic conditions, which is
similar to that observed in buckwheat (Ma and Hiradate
2000).