1. Programmed cell death-involved aluminum toxicity in yeast alleviated by antiapoptotic members with decreased calcium signals.
- Author
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Zheng K, Pan JW, Ye L, Fu Y, Peng HZ, Wan BY, Gu Q, Bian HW, Han N, Wang JH, Kang B, Pan JH, Shao HH, Wang WZ, and Zhu MY
- Subjects
- Amino Acid Sequence, Cell Proliferation drug effects, DNA Damage, Molecular Sequence Data, Reactive Oxygen Species metabolism, Saccharomyces cerevisiae cytology, Saccharomyces cerevisiae drug effects, Saccharomyces cerevisiae Proteins genetics, Saccharomyces cerevisiae Proteins metabolism, Sequence Alignment, Aluminum toxicity, Apoptosis drug effects, Calcium metabolism, Saccharomyces cerevisiae physiology, Signal Transduction
- Abstract
The molecular mechanisms of aluminum (Al) toxicity and tolerance in plants have been the focus of ongoing research in the area of stress phytophysiology. Recent studies have described Al-induced apoptosis-like cell death in plant and animal cells. In this study, we show that yeast (Saccharomyces cerevisiae) exposed to low effective concentrations of Al for short times undergoes enhanced cell division in a manner that is dose and cell density dependent. At higher concentrations of Al or longer exposure times, Al induces cell death and growth inhibition. Several apoptotic features appear during Al treatment, including cell shrinkage, vacuolation, chromatin marginalization, nuclear fragmentation, DNA degradation, and DNA strand breaks, as well as concomitant cell aggregation. Yeast strains expressing Ced-9, Bcl-2, and PpBI-1 (a plant Bax inhibitor-1 isolated from Phyllostachys praecox), respectively, display more resistance to Al toxicity compared with control cells. Data from flow cytometric studies show these three antiapoptotic members do not affect reactive oxygen species levels, but decrease calcium ion (Ca(2+)) signals in response to Al stress, although both intracellular reactive oxygen species and Ca(2+) levels were increased. The data presented suggest that manipulation of the negative regulation process of programmed cell death may provide a novel mechanism for conferring Al tolerance.
- Published
- 2007
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