This Article Full Text Full Text (PDF) All Versions of this Article: 143/1/38    most recent pp.106.082495v2 pp.106.082495v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Zheng, K. Articles by Zhu, M.-Y. Search for Related Content PubMed PubMed Citation Articles by Zheng, K. Articles by Zhu, M.-Y. Agricola Articles by Zheng, K. Articles by Zhu, M.-Y. Related Collections Biology of Transpiration

Programmed Cell Death-Involved Aluminum Toxicity in Yeast Alleviated by Antiapoptotic Members with Decreased Calcium Signals¹

State Key Lab of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310058, China

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 (Ca²⁺) signals in response to Al stress, although both intracellular reactive oxygen species and Ca²⁺ 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.

² Present address: Zhejiang Forestry Academy, Hangzhou 310023, China.

³ Present address: Department of Biotechnology, Hangzhou University of Commerce, Hangzhou 310012, China.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Mu-Yuan Zhu (myzhu{at}zju.edu.cn).

www.plantphysiol.org/cgi/doi/10.1104/pp.106.082495

^* Corresponding author; e-mail myzhu{at}zju.edu.cn; fax 86–571–88206535.

Received April 23, 2006; accepted July 10, 2006; published July 21, 2006.