1. Introduction
As a major constraint limiting crop production worldwide, water
deficit during germination stage results in a decline or even complete
inhibition of seedling emergence and stand establishment (Kaya et al.,
2006). Under drought stress, seed germination and seedling establishment were inhibited due to the drop of water potential, which results
in the decline in water uptake (Farooq et al., 2009). Oxidative damage
caused by the overproduction of reactive oxygen species (ROS) is another major problem when