Abstract
Background: In vitro techniques are an efficient tool to select salt tolerant lines in several plant species. The impacts of increasing salt concentration on membrane lipids oxidation and oxygen free radicals scavenging enzymes were evaluated in the callus of a cultivated eggplant (Solanum macrocarpon L.) and Wild Eggplant (Solanum dasyphyllum L.)
Methods: A salt stress ranging from 40 to 160 mM NaCl was imposed to callus of S. macrocarpon 'Akwaseho', a cultivated African eggplant and callus of S. dasyphyllum var dasyphyllum, a putative wild ancestor, for 40 days. Selected callus physiology and biochemistry features were investigated after 40 days of growing both species in MS medium added with NaCl at the concentration of 0 (control), 40, 80, 120 and 160 mM.
Results: A close correlation was observed between rising salinity level and the enhancement of proline accumulation. Callus of S. dasyphyllum var dasyphyllum succeeded efficiently in keeping higher K+, lower Na+ rate and Na+/K+ ratio than S. macrocarpon L. Ion content can be considered as useful tool to select salt tolerant callus tissue. Under saline condition, S. dasyphyllum L. showed lower amounts of malondialdehyde (MDA) and H2O2 but higher activity for superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) than S. macrocarpon L. in both case control and NaCl treatments.
Conclusion: The current study concluded that the two species responded differently to salinity induced oxidative damage. S. dasyphyllum L. callus showed more effective antioxidant defense system, which contributes, to better adaptive and protective capacity against salinity induced oxidative impairment by keeping more intense antioxidant enzymes activities than S. macrocarpon L. callus.