The redox state of the low molecular-weight antioxidants may modulate the degree of cell proliferation. CAT and APX play major roles in restoring the ROS homeostasis. SOD and GR work at the first and the last step, respectively, of the
ascorbate-glutathione cycle scavenging ROS in plant cells. Glutathione disulfide (GSSG) produced in the process is
then recycled to glutathione (GSH). Glutathione is essential for the cell life cycle in plants. The balance of ROS is a critical factor in cell proliferations (in the presence of favorable GSH redox state). Kumar et al. (2011) found a decrease in cell divisions in the root tip of Allium cepa after a gamma irradiation and noticed that the activities of the antioxidant enzymes remained balanced at the active stage of the developing root, helping to scavenge the excessive free radicals in the
dividing cells.