Deciphering early events involved in hyperosmotic stress-induced programmed cell death in tobacco BY-2 cells
Résumé
Hyperosmotic stresses represent one of the major constraints that adversely affect plants growth, development, and productivity. In this study, the focus was on early responses to hyperosmotic stress-(NaCl and sorbitol) induced reactive oxygen species (ROS) generation, cytosolic Ca 2+ concentration ([Ca 2+ ] cyt) increase, ion fluxes, and mitochondrial potential variations, and on their links in pathways leading to programmed cell death (PCD). By using BY-2 tobacco cells, it was shown that both NaCl-and sorbitol-induced PCD seemed to be dependent on superoxide anion (O 2 •-) generation by NADPH-oxidase. In the case of NaCl, an early influx of sodium through non-selective cation channels participates in the development of PCD through mitochondrial dysfunction and NADPH-oxidase-dependent O 2 •generation. This supports the hypothesis of different pathways in NaCl-and sorbitol-induced cell death. Surprisingly, other shared early responses, such as [Ca 2+ ] cyt increase and singlet oxygen production, do not seem to be involved in PCD.
Origine : Publication financée par une institution