Salt and drought stress exhibits oxidative stress and modulated protein patterns in roots and leaves of date palm (Phoenix dactylifera L.)

Abstract

The formation of new proteins under the influence of harsh environmental conditions is a plant adaptation reaction. Two-year-old date palm tissue culture-derived plants from ‘Barhee’ grown in the field were subjected to salt stress (70 g l-1 NaCl) and dehydration-induced by applying 70 g l-1 polyethylene glycol or without irrigation and withholding irrigation (0 g l-1) for one month. The soluble carbohydrate content increased in response to salinity and polyethylene glycol treatment in leaves compared to the control and drought treatment without irrigation. Proline increased in all treatments. Malondialdehyde and hydrogen peroxide increased under salinity. Salinity treatment increased the activity of ascorbate peroxidase and catalase enzyme. Salinity and polyethylene glycol treatments increased abscisic acid, whereas the indoleacetic acid level decreased. The protein pattern of roots and leaves in one-dimensional polyacrylamide gel electrophoresis showed that the stress conditions led to new protein bands' appearance and other proteins' disappearance. A comparison of protein patterns between the control and stress treatments revealed that the relative intensity of proteins in roots and leaves were more associated with salinity treatment than the drought. The results may be clearing important the molecular mechanism of tolerance under the influence of extreme environmental stress.