Evaluation of Protein Response of Saffron Under Osmotic Stress by Proteomics Method

Identifying the molecular-protein mechanism of saffron against osmotic stress in Iran which is one of the arid and semi-arid countries in the world is of particular importance. For this purpose and to investigate the response to osmotic stress applied with different concentrations of PEG6000, an experiment is performed using two saffron landraces of Torbat Heydarieh and Marand by hydroponic culture at the vegetative growth stage (seedling) in the greenhouse. Two weeks after osmotic stress, sampling was performed from all experimental units. According to the results, Torbat Heydarieh landrace was in a better condition than Marand landrace in terms of protein reaction under osmotic stress. Also, the results of proteomic analysis of two landraces showed that among 17 significant protein spots between control and osmotic stress treatments, four protein spots between two common landraces and six and seven protein spots were unique to Torbat Heydarieh and Marand landraces, respectively. In interpreting the specific response, it can be stated that the more tolerant landrace of Torbat Heydarieh under stress was more active in the path of antioxidant defense and included increased activity of harpin binding protein 1 and peroxiredoxin. While the more sensitive landrace Marand had more damage in different biological pathways by reducing the activity of proteins, especially the reduction of Thylakoid lumenal protein 29.8 kDa protein involved in photosynthetic light reaction. In general, the different protein responses of the landraces and the most important protein reactions and important metabolic pathways of the studied landraces of saffron were identified.