Effects of salt on lipid peroxidation and antioxidant enzyme activities of Catharanthus roseus suspension cells

Abstract

Cells of Catharanthus roseus (L.) G. Don were maintained and sub-cultured in the absence of NaCl (control) or were sub-cultured for 7 days in the presence of 50 ("50") or 100 ("100") mM NaCl, or were maintained and sub-cultured for 8 months in the continuous presence of 50 mM NaCl ("50T" or salt-adapted cells). Exposure to salt treatment reduced growth in a concentration-dependent manner. Salt-treated cells strongly accumulated Na + and, to a lesser extent, Cl -. However, no significant change in Claccumulation was observed in 50T cells.Salt progressively increased superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities whereas a strong increase in catalase (CAT) activity was only obtained in 50 and 50T cells. SOD activity was lower in 50T than in 50 cells, whereas the opposite was observed for APX activity.After native polyacrylamide gel electrophoresis (PAGE) analysis, five SOD isoenzymes were detected and the increase in SOD activity observed in salt-treated cells seemed to be mainly due to isoenzymes (SOD 1, 2 and 3). Three APX isoenzymes (APX 1, 2 and 3) were detected markedly, especially in salt-adapted cells. Salt strongly induced CAT 2 isoenzyme in 50 cells and CAT 1 isoenzyme in 50T cells. These data suggest that salt treatment provoked an oxidative stress in C. roseus cells, as shown by the increase in lipid peroxidation, in spite of the induction of antioxidant enzymes. This increase in lipid peroxidation was paralleled by a rise in lipoxygenase (LOX) activity.Increases in antioxidant activities could also be a response to the cellular damage provoked by NaCl. Probably, this increase could not stop the deleterious effects of salt, but reduced stress severity thus allowing cell growth to occur. On the other hand, and although no JA measurements has been carried out, the antioxidant enzymes could me mediated, at least 3 partially, by an LOX-mediated JA increase in salt-treated C. roseus cells. SALEM: Please penser si on laisse ce paragraph or no

ASCORBIC ACID FOLIIAR SPRAY COUNTERACTING EFFECT OF SALINITY ON GROWTH, NUTRIENTS CONCENTRATIONS, PHOTOSYNTHESIS, ANTIOXIDANT ACTIVITIES AND LIPID PEROXIDATION OF BEAN (<i>PHASEULUS VULGARIS</i> L.) CULTIVARS

“…Lipid Peroxidation (LP) is associated with damages provoked by a variety of environmental stresses. Poly-Unsaturated Fatty Acids (PUFA) are the main membrane lipid components susceptible to peroxidation and degradation (Elkahoui et al, 2005). The increase in LP, as caused by NaCl stress in the present study, can be correlated to ion accumulation and AOS production under salt stress (Hernandez et al, 2000).…”

Effect of water stress on antioxidant systems and oxidative parameters in fruits of tomato (Solanum lycopersicon L, cv. Micro-tom)

“…These results agree with previous results obtained in fruits of tomato cultivar Raissa, where water stress caused a significant increase in H 2 O 2 and MDA contents of fruits (Murshed et al 2008a). Under abiotic stress environments, the plant lipid metabolism is interrupted as a result of oxidative damage to membrane lipids by ROS and lipid peroxidation (Elkahoui et al 2005).…”

Effect of salt on ROS homeostasis, lipid peroxidation and antioxidant mechanisms in Pinus pinaster suspension cells

“…With regards to cell culture growth, it was observed that under normal conditions, P. pinaster suspension cells evidenced exponential growth and an absent lag phase, a behaviour already observed in other suspension cell models (Shimon-Kerner et al, 2000). Increasing concentrations of salt resulted in growth inhibition and eventual arrest, as expected from previous reports (Elkahouia et al, 2005). A concentration of 100 mM NaCl was subsequently chosen to impose severe salt stress without preventing cell growth.…”

“…Overexpression of various isoforms of SOD has been shown to confer improved tolerance to oxidative stress (Bowler et al, 1991;Perl et al, 1993). Moreover, overexpression of SOD and APX isozymes has been previously co-related with salt tolerance (Kaminaka et al, 1999;Wang et al, 1999), and the involvement of APX in the mechanisms of salt tolerance has also been substantiated at protein level (Elkahouia et al, 2005;Koca et al, 2007;Masood et al, 2006). Finally, present results are corroborated by microarray transcript profiling of salt-challenged Arabidopsis plants, in which all three Fe-SOD, but none other SOD isoform, presented induced expression.…”

“…An induction in the activity of SOD following salt stress has been frequently observed, either with total activity (Koca et al, 2007;Masood et al, 2006) or isoform analysis (Elkahouia et al, 2005). Previous evidence has shown that, in tobacco suspension cells, FeSOD is the main isoform involved in the control of cellular O − 2 levels (Kurepa et al, 1997).…”