Aluminum distribution and the condition of the plasma membrane in cultured tobacco cells detected using staining methods

Abstract

Using the triple staining method (FDA, PI, hematoxylin) and the lumogallion staining method, the aluminum (Al) distribution and condition of the plasma membrane in cultured tobacco cells were studied. After the cells were treated with 100 mM Al at pH 4.0 for 24 h, the triple staining method was performed to simultaneously observe the Al accumulation and any damage to the plasma membrane of the cells. These result showed that no Al accumulation to be observed in the cells whose plasma membrane was not damaged. On the other hand, Al was found to be accumulated in the nuclei, plasma membrane and other organelles when the plasma membrane was damaged, thus suggesting that Al accumulation to the organelles occurred after the plasma membrane was damaged. To study the Al accumulation in more detail, the lumogallion staining method was carried out to detect any trace amounts of Al in cells. Under confocal laser microscopy, Al binding to the organelles was detected as early as after 15 min of Al treatment. The spatial Al distribution of the cells was constructed by superposing cross section images. The stereographs showed the distribution of Al on the plasma membrane not to be uniform, thus suggesting the existence of some specific Al-binding sites where Al toxicity might be induced.