Analysis On Physiological Characters And Proteomics In Response To Cold During Spring Regrowing Period In Winter Wheat In Frigid Region

The winter wheat has not been able to grow in Heilongjiang Province for a long time before, because its location is in the frigid zone, and its duration in winter is long and the extreme low temperature in winter is very deep about among-25～-50℃and in the early spring the temperature changes largely and the late spring coldness frequently occur. The late spring coldness during overwinter re-growth stage of winter wheat is one of the major stresses to threat the production of winter wheat in the province. Many winter wheat varieties only show the characteristics of strong winter cold tolerance, but their cold hardiness often decreases too fast after the initiation in the re-growth stage of the cultivars in spring, so they can not adapt to the adversity of late spring coldness in the province. Therefore, the study for the cold hardiness in winter wheat in the re-growth stage is of great significance. In this study, the physiological and biochemical characteristics of the leaf sheath in five varieties of winter wheat as the trial material were tested in the field and the laboratory experiments and the differetial expressed protein were studied in order to provide a theoretical basis and identification approach for winter wheat breeding for cold resistance. The results were as follows:1. The highest rate of survival in spring under field conditions was Dongnong Dongmai1,85%, a minimum of Dongnong358was45%, the remaining three strains Dongnong375, Dongnong512Dongnong600is65%,71%and75%, respectively. The cold resistance in Dongnong Dongmai1is highest and in Dongnong358the minimum. By means of indoor simulation, the survival trend of Dongnong Dongmai1is as follows:As the temperature decrease and the cold treatment duration increase, there is no influence for overwinter survival in the treatment of0℃and-3℃, the rate of overwinter survival is less than87%under-6℃treatment and in-15℃/12h the rate of overwinter survival is only23%.2. The number of tillers and new roots in Dongnong Dongmai1was most than others and lest in poor cold resistance Dongnong358varieties. More tillers and new roots number of winter wheat improve the ability of cold resistance in the winter and reviving stage. The root’s activity in Dongnong Dongmai1each sampling period was higher than other strains. The level of root’s activity is directly related to reviving rate.3. The relative conductivity of the plants increases under the condition of late spring coldness, and trend gradually increased with the processing temperature and processing time increasing. The conductivity value of leaf is greater than the sheath under the same treatment.4. MDA first increase in the reviving stage of the different sampling dates and then decrease, the lowest rate of reviving of Dongnong358MDA content is always at a high level, which is contrast to Dongnong Dongmai1, whose rate of reviving is highest; the content of MDA has significantly negative correlation with reviving rate, the correlation coefficient was-0.3592, MDA content has very significant correlation with POD activity, the content of MDA has significantly correlated with the content of AsA and GSH; the content of MDA is the leading factors influencing the rate of reviving.5. With the extension of the growth time in reviving period, the content of soluble protein in tested strains firstly rise, but then decrease. The content of soluble protein differences between different varieties significantly. Soluble protein content had no significant correlation with reviving rate, the increasing in the content of soluble protein has little effect on the rate of reviving.6. SOD and POD are the two main protective enzymes in the plant cell protective enzyme system, the trend of SOD and POD in reviving stage first increased and then decreased, SOD was significantly associated with the rate of reviving. The activity of POD has little collection with the rate of reviving. the more cold resistance the sample is, the higher activity of SOD is.The activity of SOD is an important factor influencing the rate of winter wheat turning green, the direct path coefficient is0.6101. AsA and GSH are important antioxidants of plant cell, the content of AsA and GSH increased under low temperature stress, but has no obvious collection with the rate of reviving.7. Twenty six differentially expressed proteins on the leaf sheath in Dongnong Dongmai1were simulated under low temperature stress, six differentially expressed proteins repeated, the analysis of mass spectrometry was as follows:protein1was lipoxygenase, protein2was protein disulfide isomerase, protein3was ribulose1,5-bisphosphate carboxylase, protein spots4was S-adenosylmethionine synthetase, proteins5was UDP glucose pyrophosphorylase, protein spots6wqs initiation factor4F. The expression of enzymes involved in glucose synthesis and fat metabolism in the Dongnong Dongmai1enhanced after the cold treatment, contrary to initiation factor and disulfide isomerase. The expression of initiation factor (iso)4F participating in protein translation, protein disulfide isomerase, enzymes involved in glucose synthesis and fat metabolism, ribulose-1,5-bisphosphate carboxylase were raised under-6℃/12h cold treatment. Compared to-15℃/12h, with processing, The expression of ribulose-1,5-bisphosphate carboxylase was raised, in addition to ribulose-1,5-bisphosphate carboxylase under-9℃/12h treatment.