INHIBITION OF CELL GROWTH CAUSED BY ALUMINUM TOXICITY RESULTS FROM ALUMINUM-INDUCED CELL DEATH IN BARLEY SUSPENSION CELLS

Abstract

The inhibition of cell growth caused by aluminum (Al) toxicity was studied in barley (Hordeum vulgare L., cv. Zaoshu 3 from our laboratory) suspension cells in this paper. The growth of suspension cells in 0.1–5.0 mM Al treatment groups was obviously inhibited in 24-h Al treatments and was not recovered during 24-h recovery culture without Al. On the average, 46.70% or 83.36% of suspension cells lost viability respectively during 24-h Al treatments or 24-h recovery culture by the detection of trypan blue staining. The agarose gel electrophoresis shows that DNA ladders were induced after 24-h Al (0.1–5.0 mM) treatments. Al toxicity significantly inhibits cell division and promotes chromosomal variation, but the mitotic index (MI) of suspension cells is so low that the inhibition of Al toxicity on cell division does not cause the significant inhibition of cell growth after short-term exposure to Al. These results suggest that Al-induced inhibition of cell growth mainly results from cell death occurring during Al treatments or recovery culture, which can occur possibly via programmed cell death (PCD)-related signal transduction pathway.