Can He-Ne Laser Induce Changes in Oxidative Stress and Antioxidant Activities of Wheat Cultivars from Kazakhstan and Egypt?

Recently the biostimulatory role of physical methods have been observed in major agricultural crop plants, He-Ne laser is one of the most significant biophysical method for enhancing not only seed germination but also plant growth and development. Seeds of wheat cultivars from Kazakhstan (cultivars; aksay, kazakhstanskaya-10 and eretrospermum-350) and from Egypt (cultivar; sakha-168) were exposed to He-Ne laser irradiations with 5 mW. mm−2 power intensity for 1 to 1800 seconds exposition time. Various germination and growth parameters and indices were recorded and calculated. Changes on the rate of superoxide dismutase activity, lipid peroxidation level and hydrogen peroxide accumulation were monitored. Wheat seed pre-treatment caused significant increase in various germination parameters including germination percentage, germination rate (seed.h−1), relative germination rate coefficient (Wk) and enhancing various growth parameters. Several doses of He-Ne laser promoted the germination to a maximum of 100 germination, increasing also the germination rate. Moreover, seed pretreatment with different doses of He-Ne laser caused significant changes in levels of hydrogen peroxide, lipid peroxidation and Cu-Zn superoxide dismutase activity. Hydrogen peroxide accumulation and lipid peroxidation levels increased dramatically with the increasing doses of helium neon laser compared to control. However Cu-Zn superoxide dismutase activities dropped following seed pretreatment with He-Ne laser compared to control.