UV Irradiation Effects on Seed Germination and Growth, Protein Content, Peroxidase and Protease Activity in Red Bean

Ultraviolet radiation is energetically capable of disrupting proteins. Ultraviolet radiations Are divided into three bands included UV-A (320-390 nm), UV-B (280-320 nm) and UV-C(254-280nm). Several studies have indicated that enhanced UV-B radiation can deleteriously affect physiological processes and overall growth in some plants species.Bean Sayad and Bean Derakhshan seeds irradiated with 220 to 400 nm UV rays were grown in incubator for 8 days at 25±°C. Germination, growth (seedling fresh weight, root shoot length and their ratio), lipid peroxidation, protease and peroxidase activity were measured in leaves. Results showed that percent germination of the seeds and the rates of growth of sprouts were inversely related to the irradiation doses. In Derakhshan, peroxidase and protease activities (two folds) and MDA contents were higher as compared to Bean Sayad while vice versa for protein contents, revealing inherent differences between two types. Data for protein contents,peroxidase and protease activities therefore suggested that irradiation dose should not under 300nm UV in Bean Derakhshan and also 300nm UV in Bean Sayad. In Bean Derakhshan 320 to 400 nm UV irradiation dose non-significantly affected the protein contents and peroxidase activity and uppered MDA contents and protease activity. In Bean Sayad 300 nm UV irradiation dose increased the peroxidase activity,uppered the MDA contents and affect the protein content and protease activity. It was concluded that protein contents, protease, peroxidase and lipid peroxidation may be used in early assessment of effectiveness and superiority of radiation dose to induce mutations