effects of salinity and laser radiation on proline accumulation in seeds of spring wheat

laser is one of the sources that induce a biological effect in higher plants. the positive effect of laser on some crops has been proved. this research was carried out to study the effect of laser radiation on the accumulation of proline in spring wheat (triticum aestivum cv. kavir) under different nacl treatment levels. semi-coherent red beam, infrared beam and one-second harmonics of neodymium-yttrium-alminum garnet (nd:yag) laser were chosen as illumination sources. irradiation on seeds was conducted for 12 minutes once or twice and non-irradiated seeds were used as the control. experiment was conducted as factorial based on completely randomized design with three replications. the results revealed proline accumulation in leaves after laser treatment and subsequently salt stress tolerance enhanced significantly. each dosage of radiation imposed a different effect on proline content. the highest proline accumulation was observed in one-time exposure of nd:yag laser radiation. this is the first investigation report on using different types of lasers and their effect on proline content in the spring wheat. results show the powerful effect of laser treatment on the improvement of wheat tolerance to salinity stress.