THE ROLES OF ASCORBIC ACID AND Α-TOCOPHEROL IN MINIMIZE OF SALT-INDUCED WHEAT FLAG LEAF SENESCENCE | ||||
| Journal of Plant Production | ||||
| Article 10, Volume 34, Issue 11, November 2009, Page 10645-10661 PDF (815.14 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jpp.2009.119172 | ||||
 View on SCiNiTO | ||||
| Author | ||||
S. F. Gadalla  
| ||||
| Agricultural Botany Department, Faculty of Agriculture, Mansoura University, Egypt. | ||||
| Abstract | ||||
| Experiments were conducted to study the α-tocopherol and ascorbic acid on modify the leaf senescence process of wheat grown under three salinity levels (0.8, 7.5, and 11.5 dSm-1). The parameters analyzed were soluble protein content, chlorophyll content, electrolyte permeability, ions content, lipid peroxidation, hydrogen peroxide content, catalase and peroxidase activities, ascorbic acid content, phenol, and total carotenoids contents. Salinity hastened the naturally-occurring senescence rate of wheat flag leaves, it decreased concentrations of chlorophyll, total carotenoids, ascorbic acid, total phenol, calcium, potassium, magnesium, K+/Na+ ratio and soluble protein contents as well as the activities of Catalase and peroxidase. On the other hand, it increased sodium and chloride and chlorophylla:b ratio as well as membrane permeability, hydrogen peroxide content and malondialdehyde content. Spraying with both antioxidants reduced the hydrogen peroxide accumulation, lipid peroxidation, membrane permeability, sodium and chloride content, whereas the antioxidants enzyme activities (catalase, and peroxidase) were increased. Enhanced accumulation of ascorbate, phenol, carotenoids, calcium, potassium and magnesium was recorded in antioxidants-sprayed plants at 65 days after sowing. Under moderate and sever salinity levels both antioxidants alleviated the harmful effects of salinity on leaf senescence related parameter. The higher levels of antioxidants (ascorbic acid, phenol, carotenoids) and low level of H2O2 in flag leaf may be the prerequisite for delayed leaf senescence in antioxidants-sprayed plants. It can be concluded that ascorbic acid- sprayed plants can postpone the leaf senescence by peroxide/phenolic/ascorbate system which is involved in scavenging the ROS produced during leaf senescence. | ||||
| Keywords | ||||
| antioxidants; malondialdehyde; salinity; senescence; wheat | ||||
|
Statistics Article View: 104 PDF Download: 263 |
||||
