Leaf protein pattern of tolerant and susceptible canola cultivars under drought stress

Drought stress is the main restriction factor in crop production that has an adverse effect on crop quantity and quality. Canola, like many crops, is affected by stress due to water deficit. At the cellular level, plants respond to drought stress by synthesizing specific proteins. Therefore, a research with the aim of studying the response mechanism of canola to drought stress and determining proteins involved in mediating stress tolerance was carried out. 

In order to comprehend a mechanism of canola plant response to drought stress, the protein profiles of the drought-tolerant Hyola308 and drought-sensitive Sarigol leaf under different drought stress conditions based on a gel-free/label-free proteomic technique were investigated. To validate the content variation of proteins identified in the proteomic analysis, Western blot analysis was used. 

A total of 56 proteins were identified in Sarigol and Hyola308, 16 proteins were specific to Hyola308 and 16 proteins were specific to Sarigol, respectively. Of the identified proteins, 12 proteins were commonly detected between Sarigol and Hyola308. In Sarigol under different drought stress conditions, the abundance of proteins related to protein metabolism, photosynthesis and energy metabolism decreased; whereas, in Hyola308, an enhancement in proteins abundance involved in photosynthesis, energy metabolism and antioxidant defense was observed. 

It is inferred that enhancement of these protein abundance in Hyola308 leaf may be a part of tolerance mechanism of this cultivar exposed to stress and decrease in the Kelvin cycle efficiency and production of sugar and energy in Sarigol may justify growth reduction of this cultivar.