Light interacts with salt stress in regulating superoxide dismutase gene expression in Arabidopsis

• Published in: Plant science (Limerick) Vol. 177; no. 3; pp. 161 - 167
• Main Authors: Attia, Houneida, Karray, Najoua, Lachaâl, Mokhtar
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01-09-2009; [Ireland]: Elsevier Science Ireland Ltd; Elsevier
• Subjects: antioxidant activity; Arabidopsis thaliana; Arabidopsis thaliana, Salinity; Biological and medical sciences; Biomass; enzyme activity; Fundamental and applied biological sciences. Psychology; Gene expression; gene expression regulation; Light; light intensity; oxidative stress; plant development; plant growth; salt stress; Superoxide dismutase; Superoxide dismutase; Arabidopsis thaliana, Salinity; Gene expression; Light; Enzyme; Plant biology; Stress; Salinity; Arabidopsis thaliana; Cruciferae; Dicotyledones; Angiospermae; Spermatophyta; Oxidoreductases; Experimental plant
• ISSN: 0168-9452; 1873-2259
• DOI: 10.1016/j.plantsci.2009.05.002

Arabidopsis thaliana plants (
Col,
Columbia, and
N1438) were grown for 15 d under two light regimes providing different growth rates. The medium contained 0–85
mM NaCl. Shoot biomass and ion accumulation were measured. Superoxide dismutase (SOD) activity was assayed on gels, and the expression of six SOD genes was studied using real-time PCR. Mean growth rate was increased in high light (HL) regime as compared to low light (LL) regime. Parallely, most of SOD genes were overexpressed in
Col and underexpressed in
N1438 in response to HL. At 50
mM NaCl, plant growth was inhibited and a complex pattern of SOD gene expression was recorded. These responses varied according to the light regime, and differed between the accessions. This pattern, including the differences between the accessions, could be interpreted as a consequence of interaction between light and salt, hypothesizing that oxidative stress occurred when light energy input exceeded energy utilization when salt inhibited growth, and that oxidative stress induced overexpression of some SOD genes. Salt-induced excess Na
+ accumulation in leaves and limitation of K
+ provision to these organs might also participate in eliciting SOD genes’ response. Variability was observed between the two accessions for all these traits.