Canola Seedling Response to NaCl Stress – a Proteomic Approach

Abstract

Salinity is a major abiotic stress worldwide, which causes a tremendous loss in the quality and quantity of agricultural products. In order to identify defense mechanisms to salinity-induced stress, a two-dimensional electrophoresis approach was used to investigate proteins achieved from canola cultivar ‘Option 500’ seedlings, after plants had been treated with NaCl. The 300 mmol NaCl treatment caused a significant decrease in fresh and dry weight as well as plant height and increment of proline content compared with control group. There were no significant changes in the quality of catalase and peroxidase activity. Out of 110 repeatable protein spots, 44 were registering change, according to induction factor index. 7 spots were recognized significant at 1% probability level statistically. These proteins were involved in energy production, ROS scavenging and suppressor, and those involved in photosynthesis. Production of chloroplastic fructose-bisphosphate aldolase enzyme along with carbohydrate metabolisms of Kelvin cycle and glycolysis increases under salinity condition. The amount of Cu/Zn SOD in chloroplast reduces in response to salinity which results from an increase in OH^- radicals. Expression of photosynthesis proteins have been reduced probably as a consequence of the drop in osmotic pressure resulted from water scarcity and stomata closure, which reduces the availability of Co₂.