Abstract: The interactive effects of salinity water, 50, 100 and 200 mM) and 100 ppm of nicotinamide
(Vit. pp) or ascorbic acid (Vit. C) either as grain soaking or shoot spraying on Zea mays plant were
studied to study its response to salinity stress and the possible role played by vitamins (Vit. PP or
Vit. C) in regulating salt-induced changes in growth, some relevant metabolic activities and oxidative
3 defense systems of Zea mays plant. All growth criteria, IAA, GA , photosynthetic pigments, insoluble
sugar and total carbohydrate contents were significantly decreased with increasing salinity levels, while
ABA soluble sugars and amylases activity were sharply increased as compared with the control.
Applications of vitamins (Vit pp or Vit. C) as grain soaking or shoot spraying could alleviate the adverse
3 effects of salinity on growth parameters which were accompanied by marked increases in IAA, GA ,
photosynthetic pigments and carbohydrate contents, and decreases in ABA and amylases activity as
compared with those of the reference controls. On the other hand, activity level of superoxide dismutase
(SOD), peroxidase (POD) enzymes and lipid peroxidation (MDA) showed progressive significant increases
with increasing salinity levels, while the behaviour of catalase (CAT) activity and reduced glutathione
content showed an opposite response as compared with the control. Treatment with Vit. pp or Vit. C by
any of the two methods (soaking or spraying) induced significant reduction in the activities of SOD,
peroxidases and lipid peroxidation, and significant increases in catalase activity and reduced glutathione
content under salt stress as compared with reference controls. |
