Hajaji Afef

Title : Citric acid is a crucial compound playing an alleviation role of salt-induced oxidative stress in moringa oleifera

Abstract:

Growth performance and antioxidative system of salt treated-Moringa oleifera were exanimated in presence of citric acid as a component of response to abiotic stress. Germinated Moringa oleifera seeds were transferred on sandy and vermicular (1/2 w/w) soil and watered by Hoagland solution. After two weeks, seedling were irrigated by Hoagland solution in absence of salt (Control), in presence of 10g/l or 10g/l NaCl +10mM Citric acid. Moringa oleifera growth is significantly affected by salinity (10g/l). In fact, irrigation by salt water causes diminution of shoot fresh weight and leaves morphological parameters,photosynthetic pigments and total soluble proteins contents. In another way, salt stress induced accumulation of total free amino acids, soluble sugar and proline tenors. When citric acid is supplied in irrigation solution, a significant enhancement of leaves morphological parameters, shoot growth, photosynthetic pigments and total soluble proteins contents. The important content of citric acid in leaves tissues accompanied by diminution of total free amino acids, soluble sugar and proline tenors. More that, under salinity stress condition, MDA (Malondialdehyde) and Hydrogen peroxide;H2O2 accumulation was detected reflecting the imbalance situation in leaves tissues and membrane damage caused by induced- oxydatif stress. Antioxidative enzymes stimulation was showed through activation of superoxidase dismutase (SOD) and catalase (CAT). A dramatic drop of MDA and H2O2 contents accompanied by notably loss of SOD and CAT activities were showed when citric acid is supplied simultaneously with salt in irrigation solution. Therefore, citric acid play a crucial role in the improvement of Moringa oleifera plants ability to resist against salinity stress.

Biography:

Dr. Hajaji Afef studied Biology at the Tunisian University El Manar, Tunisia and graduated as advanced studies diploma in 2003. She then joined the research group of Prof. Ghorbel Mohamed Habib at the Tunisian Faculty of Sciences. She received her PhD degree in 2010 at the same institution. She occupied the post of Research assistant until 2015. After that, she obtained the position of an Assistant Professor at the University of Djeddah. In 2020 she joined the research group of Prof. Ammari Youssef and occupied the post of Research Assistant at the University of Carthage. She has published more than 35 research articles in scientific journals