Cell death induced by sodium nitroprusside and hydrogen peroxide in tobacco BY-2 cell suspension

Abstract

The interplay between nitric oxide (NO) and reactive oxygen species can lead to an induction of cell death in plants. The aim of our work was to find out if cyanide released from sodium nitroprusside (SNP; a donor of NO) could be involved in the cell death induction, which is triggered by SNP and H 2O2. Cell suspension of Nicotiana tabacum L. (line BY-2) was treated with 0.5 mM SNP, 0.5 mM potassium ferricyanide (PFC; analogue of sodium nitroprusside which can not release NO) and/or by 0.5 mM glucose with 0.5 U cm-3 glucose oxidase (GGO; a donor system of H2O 2). The cell death was induced only by combination of SNP and GGO. Thus cyanide released was not involved in the induction of cell death. However, SNP showed toxic effect because of decrease in activities of intracellular oxidoreductases and esterases. The cell death caused by SNP and GGO occurred within 12 h. During cell death either length or width of the cell increased. Central vacuole was formed in 20 to 40 % of cells. Most of the dead cells showed a condensed cytoplasm. Two hallmarks of programmed cell death (PCD), chromatin condensation and blebbing of nuclear periphery, were observed. However, oligonucleosomal fragmentation of DNA, another hallmark of PCD, was not detected. © 2007 Institute of Experimental Botany, ASCR.