Tag Archives: plant cells

Induction of plant cells heat resistance by hydrogen sulfide donor is mediated by H(2)O(2) generation with participation of NADPH oxidase and superoxide dismutase

Yu. E. Kolupaev1,2, E. N. Firsova1, Т. О. Yastreb1

1V.V. Dokuchaev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@ukr.net;
2V.N. Karazin Kharkiv National University, Ukraine

The participation of enzymatic systems carrying out generation and conversion of reactive oxygen species (ROS), in realization of the stress-protective effect of hydrogen sulfide (H2S) on wheat coleoptile cells was investigated. It has been shown that the treatment of isolated coleoptiles with a 100 μM hydrogen sulfide donor sodium hydrosulfide (NaHS) caused a transient enhancement of the generation of superoxide anion radical (O2•–), an increase of hydrogen peroxide content and superoxide dismutase (SOD) activity in them. The increase in ROS generation was eliminated by the inhibitor of NADPH oxidase imidazole, but not by the peroxidase inhibitor sodium azide. Treatment of coleoptiles with SOD inhibitor sodium diethyldithiocarbamate (DDC) enhanced the generation of O2•– and neutralized the effect of increasing H2O2 content induced by NaHS. One day after treatment with the H2S donor, the generation of ROS decreased to a control level, while the activity of antioxidant enzymes increased markedly and the resistance of coleoptiles to damaging heating­ was increased. These effects of the hydrogen sulfide donor were eliminated by coleoptiles’ treatment with inhibitors of NADPH oxidase (imidazole) and SOD (DDC). It was concluded that both NADPH oxidase, genera­ting O2•– , and SOD, which turns it into H2O2 performing signaling functions, are involved in the formation of a signal that induces protective systems and causes an increase in heat resistance of plant cells.

Reactive oxygen species and stress signaling in plants

Yu. E. Kolupaev, Yu. V. Karpets

V. V. Dokuchaev Kharkiv National Agrarian University, Ukraine;
e-mail: plant_biology@mail.ru

Data on the basic processes and the compartments, involved in formation of reactive oxygen species (ROS) in plant cells, are generalised. The features of structure and regulation of NADPH-oxidase as the one of main enzymatic producers of ROS are characterized. The two-component histidine kinases, ROS-sensitive transcript-factors, ROS-sensitive protein kinase and redox-regulated ionic channels are discussed as the possible sensors of redox-signals in plant cells. The interaction between ROS and other signal mediators, in particular nitric oxide and calcium ions, is discussed. The ROS role as the signal mediators in the development of plant resistance to hyperthermia, osmotic shock and other abiotic stressors is analyzed.