Effect of salinity on biochemical components of the egg plant (Solanum melongena)

Abstract

Present study explored the effect of salinity stress on seedling mineral composition, chlorogenic acid and polyphenol oxidase content of the two genotypes (GT25 and GT26) of egg plant (Solanum melongena L.). Selected egg plant genotypes were exposed to salinity stress (25-150 mM NaCl) along with control. Plants were grown in the field of School of Biotechnology, Gautam Buddha University during 2018-19. Drastic impacts of salinity stress as preliminary symptom were seen on seed germination. Genotype GT25 and GT26 were proficient to germinate only up to 100 mM and 75 mM NaCl respectively under salinity treatment. Results showed very poor growth along with necrotic/ dead tissue in the germinated seedlings leaves after the 30 days salt treatment in GT26 in100 mM NaCl treatment. Accumulation of Na+ ions is comparatively lower (67%) in GT25 under 75 mM NaCl concentration. On the contrary mineral (Cu, Mn, K) content, enzymatic activity like chlorogenic acid and polyphenol were resulted higher in GT25 compared to GT26 when subjected to NaCl stress (75 mM). These results indicate that egg plant genotypes respond to salt induced oxidative stress by enzymatic defense systems. The accumulation of polyphenol and chlorogenic acid suggest a role in protective metabolites. Hence it can be concluded that the GT25 possess strong tolerance against salt stress and could be an important genotype resource for the salt tolerance breeding programme of egg plant.

Keywords

• Chlorogenic acid
• Egg plant
• Mineral content
• Polyphenol oxidase
• Salinity stress