Weak microwave can alleviate water deficit induced by osmotic stress in wheat seedlings

• Published in: Planta 2009-01, Vol.229 (2), p.291-298
• Main Authors: Chen, Yi-Ping, Jia, Jing-Fen, Han, Xiao-Ling
• Format: Article
• Language: English
• Subjects: Agriculture; alpha-Amylases - metabolism; Ascorbic Acid - metabolism; Biological and medical sciences; Biomass; Biomedical and Life Sciences; Catalase - metabolism; Ecology; Emissions; Enzymes; Forestry; Fundamental and applied biological sciences. Psychology; Glutathione - metabolism; Irradiation; Life Sciences; Magnetic field strength; Magnetic fields; Magnetics; Malondialdehyde - metabolism; Microwave radiation; Microwaves; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase - metabolism; Original Article; Osmotic Pressure - drug effects; Osmotic Pressure - radiation effects; Oxidative stress; Peroxidase - metabolism; Photons; Plant Sciences; Plants; Polyethylene Glycols - pharmacology; Pretreatment; Radiation damage; Radiation dosage; Seedlings; Seedlings - anatomy & histology; Seedlings - drug effects; Seedlings - enzymology; Seedlings - radiation effects; Seeds; Seeds - drug effects; Seeds - radiation effects; Superoxide Dismutase - metabolism; Superoxides; Surface Properties - drug effects; Surface Properties - radiation effects; Temperature; Time Factors; Triticum - drug effects; Triticum - enzymology; Triticum - radiation effects; Water - physiology; Water deficit; Wheat
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-008-0828-8

The aim of the investigation is to determine the effect of microwave pretreatment of wheat seeds on the resistance of seedlings to osmotic stress. Changes in biophysical, physiological and biochemical characters were measured. The results showed: (1) The magnetic field intensity and seeds temperature increased progressively with microwave pretreatments of 5, 10, 15, 20 s and 25 s compared with controls. Although each microwave pretreatment resulted in an increase in α-amylase activity and photon emission intensity, the increase of α-amylase activity and photon emission intensity was maximal at a microwave pretreatment of 10 s. (2) Osmotic stress induced by PEG treatment enhanced the concentration of malondialdehyde, while decreasing the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid, glutathione in the seedlings compared with controls. However, compared to osmotic stress alone, in the seedlings treated with microwave irradiation plus osmotic stress the concentration of malondialdehyde decreased, while the activities of nitricoxide synthase, catalase, peroxidase, superoxide dismutase and the concentration of nitric oxide, ascorbic acid and glutathione increased. These results suggest that a suitable dose of microwave radiation can enhance the capability to eliminate free radicals induced by osmotic stress in wheat seedlings resulting in an increase in resistance to osmotic stress.