Dihydrosphingosine-induced programmed cell death in tobacco BY-2 cells is independent of H₂O₂ production.

Autor: Lachaud C; UPS, UMR 5546, Surfaces Cellulaires et Signalisation chez les Végétaux, Université de Toulouse, BP 42617, F-31326 Castanet-Tolosan, France., Da Silva D, Amelot N, Béziat C, Brière C, Cotelle V, Graziana A, Grat S, Mazars C, Thuleau P
Jazyk: angličtina
Zdroj: Molecular plant [Mol Plant] 2011 Mar; Vol. 4 (2), pp. 310-8. Date of Electronic Publication: 2011 Jan 03.
DOI: 10.1093/mp/ssq077
Abstrakt: Sphinganine or dihydrosphingosine (d18:0, DHS), one of the most abundant free sphingoid Long Chain Base (LCB) in plants, has been recently shown to induce both cytosolic and nuclear calcium transient increases and a correlated Programmed Cell Death (PCD) in tobacco BY-2 cells. In this study, in order to get deeper insight into the LCB signaling pathway leading to cell death, the putative role of Reactive Oxygen Species (ROS) has been investigated. We show that DHS triggers a rapid dose-dependent production of H₂O₂ that is blocked by diphenyleniodonium (DPI), indicating the involvement of NADPH oxidase(s) in the process. In addition, while DPI does not block DHS-induced calcium increases, the ROS production is inhibited by the broad spectrum calcium channel blocker lanthanum (La³+). Therefore, ROS production occurs downstream of DHS-induced Ca²+ transients. Interestingly, DHS activates expression of defense-related genes that is inhibited by both La³+ and DPI. Since DPI does not prevent DHS-induced cell death, these results strongly indicate that DHS-induced H₂O₂ production is not implicated in PCD mechanisms but rather would be associated to basal cell defense mechanisms.
Databáze: MEDLINE
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