Antioxidant enzymes during hypoxia-anoxia signaling events in Crocus sativus L. corm.

The activity of reactive oxygen species (ROS)-scavenging enzymes, catalase, superoxide dismutase (SOD), glutathione peroxidase, o-dianisidine and ascorbate peroxidases, was investigated in Crocus sativus L. corms cultivated in normoxic and hypoxic-anoxic conditions. The activity of the ROS-scavenging enzymes studied varied during cultivation. However, the pattern of ROS-scavenging enzymes production was different in corms cultivated in normoxic and hypoxic-anoxic conditions. In normoxic conditions, only the activities of peroxidases and SOD were stimulated. In dormant corms placed under hypoxia-anoxia, the activities of catalase, SOD, and glutathione peroxidase were stimulated, with the highest stimulation observed for catalase, followed by SOD, and then glutathione peroxidase. In corms that had been rooted for 3 days before being placed in hypoxia-anoxia, the activities of all ROS-scavenging enzymes studied were stimulated with the highest stimulation still observed for catalase, followed by the peroxidases, and finally SOD. Thus catalase was the prevailing enzyme produced under hypoxia-anoxia.