Nigella sativa is a medicinal herb and its seeds are used as an important spice and condiment. Seed germination is a complex process that involves the activation of specific enzymes at the appropriate times and regulation of their activity. Seed germination percentage might be related to the efficiency of free radical scavenging in dry seeds. Oxidative stress is induced by a wide range of environmental factors including heavy metals stress. Therefore, antioxidant resistance mechanisms may provide a strategy to enhance metal tolerance and processes underlying antioxidant responses to metal...