Effect of salinity and radiation on proline accumulation in seeds of canola (Brassica napus L.)

Since laser beam may affect plant traits, it was used to enhance accumulation of proline in rapeseed and therefore to improve its tolerance to the salinity stress. This investigation was performed to study the effect of NaCl concentration in irrigated water (0, 100, 200 and 300 mmol NaCl) on proline accumulation of Canola (Brassica napus L.) after laser irradiation (Red, Infra-red and Nd:YAG) at two exposure treatments. In each exposure, seeds were irradiated for three minutes once or twice by the laser set. Free proline content in leaves increased significantly by increasing of NaCl concentration. Also proline content significantly increased with irradiation by laser beam. The Red laser irradiation used once and the Nd:YAG laser used twice had the greatest effect on the proline content whereas the Infrared laser had a low effect. Double application of irradiation induced a significantly higher amount of proline in the leaves compared to only one application. This is the first report on using different lasers irradiation on proline content in a winter rapeseed.