Water is a major limiting factor affecting plant growth, development and yield mainly in arid and semi-arid region where plants are often exposed to periods of water deficit stress which is also known as drought stress (Foyer et al., 1994). Drought and heat stress can cause oxidative stress through the production of reactive oxygen species such as super oxide radicals and hydrogen peroxide. Also the drought, salinity, extreme temperatures and oxidative stress are often interconnected and may induce similar cellular damage. Plant growth and productivity is adversely affected by...