Abstract: Using He-Ne laser irradiation to repair the ROP GTPase damage by the enhanced UV-B radiation in wheat seedlings has been studied. We extracted small G protein, and then determined its content by SDS-PAGE electrophoresis. At the same time, we tested the FITC fluorescence intensity of wheat microfilament marker by using a laser scanning confocal microscope. The results showed that, the enhanced UV-B radiation reduced the Rop protein content in wheat seedlings, and we also found that it changed the shape of protoplast by LCSM scanning.The intensity of the fluorescence which marks damaged cytoskeletal by the enhanced UV-B radiation was weaken. Moreover, in the whole period of UV-B treatment, the fluorescence degree was lower than the control group (CK). Then, after treating with the He-Ne laser, the content, the shape and the intensity were all increased, but still lower than the control guoup. From the above descriptions, we can say that the UV-B radiation could decrease the Rop GTPase content of wheat seedlings and damage microfilament cytoskeleton. However, a fixed dose of laser played a role in repairing the low protein content and the cell cytoskeleton damaged by the UV-B radiation. By the way, the Rop proteins participate in the reorganization of the actin cytoskeleton.

Key words: He-Ne laser, Rop GTPase, SDS-PAGE electrophoresis, UV-B radiation, Wheat seedling