Proteomic analysis of spring freeze-stress responsive proteins in leaves of bread wheat (Triticum aestivum L.)

Following three-day exposure to −5 °C simulated spring freeze stress, wheat plants at the anther connective tissue formation phase of spike development displayed the drooping and wilting of leaves and markedly increased rates of relative electrolyte leakage. We analysed freeze-stress responsive proteins in wheat leaves at one and three days following freeze-stress exposure, using two-dimensional electrophoresis and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Our results indicate that out of 75 protein spots successfully identified under freeze-stress conditions 52 spots were upregulated and 18 were downregulated. These spring freeze-stress responsive proteins were involved in signal transduction, stress/defence/detoxification, protein metabolism (i.e. translation, processing, and degradation), photosynthesis, amino acid metabolism, carbohydrate metabolism, and energy pathways, and may therefore be functionally relevant for many biological processes. The enhanced accumulation of signal transduction proteins such as a C2H2 zinc finger protein, stress/defence/detoxification proteins including LEA-related COR protein, disease resistance protein, Cu/Zn superoxide dismutase, and two ascorbate peroxidases may play crucial roles in the mechanisms of response to spring freeze stress in wheat plants. Wheat plants at the anther connective tissue formation phase of the spike development stage were exposed to −5 °C simulated spring freeze-stress conditions for 3 days. Spring freeze-stress responsive proteins were identified by 2-DE and MALDI-TOF/TOF-MS. The results indicated that 75 responsive proteins were differentially regulated under freeze-stress conditions. These spring freeze-stress responsive proteins, involved in signal transduction, stress/defence/detoxification, protein metabolism, photosynthesis, amino acid metabolism, carbohydrate metabolism, and energy pathways, may be functionally associated with responses to freeze stress. [Display omitted] ► Wheat plants at the anther connective tissue formation phase were exposed to −5 °C. ► The proteome of these freeze-stressed plants was analysed. ► Seventy-five responsive proteins were identified by 2-DE and MALDI-TOF/TOF-MS. ► Some proteins were involved in signal transduction and defence pathways. ► This study helps to understand molecular mechanism of spring freeze stress in wheat.