Copper-mediated oxidative burst in Nicotiana tabacum L. cv. Bright Yellow 2 cell suspension cultures

Abstract

In cell suspension cultures of Nicotiana tabacum L. cv. Bright Yellow 2 (BY-2) a rapid and concentration-dependent accumulation of H(2)O(2) is induced by excess concentrations of copper (up to 100 microM). This specific and early response towards copper stress was shown to be extracellular. Addition of 300 U of catalase per ml decreased the level of H(2)O(2). Superoxide dismutase (5 U/ml) induced an increase in H(2)O(2) production by 22.2%. This indicates that at least part of the H(2)O(2) is produced by dismutation of superoxide. Pretreatment of the cell cultures with the NAD(P)H oxidase inhibitors diphenylene iodonium (2 and 10 microM) and quinacrine (1 and 5 mM) prevented the generation of H(2)O(2) under copper stress for 90%. The influence of the pH on the H(2)O(2) production revealed the possible involvement of cell-wall-dependent peroxidases in the generation of reactive oxygen species after copper stress.

Cadmium and zinc-mediated oxidative burst in tobacco BY-2 cell suspension cultures

“…The time course of this oxidative burst was similar to that induced by elicitors (Qin et al 2004), for cantharidine (Van Gestelen et al 1998) and for a copper-induced response (Raeymaekers et al 2003). The induction of an oxidative burst response has often been observed to be biphasic, with a rapid induction within about 60 min, and a slower second phase.…”

“…H 2 O 2 production was measured spectrophotometrically as the peroxidase-dependent oxidation of 1 mM 3,5-dichloro-2-hydroxybenzensulfonic acid (DCHBS) to its quinine form, which specifically reacts with 0.1 mM 4-aminoantipyrine (AAP) to generate a molecular complex absorbing at 510 nm (Van Gestelen et al 1998;Raeymaekers et al 2003). The oxidation of DCHBS is believed to be mediated by peroxidases abundantly present in the cell wall.…”

Linked activation of cell division and oxidative stress defense in alfalfa leaf protoplast-derived cells is dependent on exogenous auxin

“…In order to avoid measuring cell death-related H 2 O 2 accumulation, the rate of H 2 O 2 release during a 1-h period was determined and used to compare treatments. This parameter can be easily determined in a nondestructive way and has already been shown to be useful for the measurement of extracellular H 2 O 2 production in suspension-cultured cells in response to stress (Van Gestelen et al 1998b;Raeymaekers et al 2003).…”

Antioxidant responses to enhanced generation of superoxide anion radical and hydrogen peroxide in the copper-stressed mulberry plants

“…While excess of Cu in the cellular environment is known to induce oxidative stress (Weckx and Clijsters 1996;Navari-Izzo et al 1998;Gupta et al 1999;Pa¨t-sikka¨et al 2002;Raeymaekers et al 2003;Morelli et al 2004;Lombardi and Sebastiani 2005), it could be a cause of accelerated senescence which could help plants in shedding off Cu-rich older leaves. Potential toxicity of increased DHA concentration (Paciolla et al 2001) or disturbed redox status of the cellular environment due to increased DHA/AsA ratio could have caused accelerated senescence and poor growth of the Cu-excess plants.…”

“…GR also plays a key role in the antioxidant defence processes, by reducing oxidized glutathione (GSSG) in a reaction which utilizes NADPH, thus allowing a high GSH/GSSG ratio to be maintained (Apel and Hirt 2004). Though many reports concerning Cu-excess induced oxidative stress and antioxidant responses are available (Gupta et al 1999;Teisseire and Guy 2000;Nagalakshmi and Prasad 2001;Drą _ zkiewicz et al 2003;Raeymaekers et al 2003;Morelli and Scarano 2004;Lombardi and Sebastiani 2005), we find a general lack of information on induction of ROS generation and antioxidant responses in Cu-deficient plants. The study presented here implicates enhanced generation of ROS consequent to deficient or excess supply of Cu in the development of deficiency or toxicity effects of Cu in mulberry plants.…”