Research Of The Expression And Sub-Cellular Localization Of Dehydrin-Like In Wheat Leaves Under Water Stress

A variety of stress response proteins will be produced during dehydration stress in plants, one of the responsive proteins was named late embryogenesis abundant protein (LEA) in the dehydration of D-11 family protein (dehydrin). Dehydrins are thermostability and highly hydrophilic,Glycine and Lysine is rich in them. Dehydrations contains its special conservative, now finding three classes very conservative regions named K, S and Y fragments, all dehydrated proteins including K-segments,therefore using K-segments homologous antibody to peptide fragments in detecting and locating dehydration protein. Dehydration exists in various parts of the plant cell, the majority of them exists in the nucleus and cytoplasm, and it is also distributed in the mitochondria and plasma membrane.Different plants and organizations, diverse stress condition (drought and salinity, temperature, et al.) in the dehydration induced produce intracellular distribution also vary.In the nucleus, dehydration exists in unstained euchromatin, heterochromatin, nuclear membranes and nucleolus; And in the nucleus outside,it mainly exists in the cytoplasm matrix,the mere existence in organelles.Two different drought resistance winter wheat: drought resistance stronger'ShanHe 6'and drought resistance weaker'ZhengYin 1'as experimental materials in this study, wheat seedlings by PEG stress, with the colloidal gold immune electron microscopy technique and Western blot, this study investigated the distribution of subcellular structures of dehydrated protein expression in wheat under water stress, combined with its cell membrane relative permeability and soluble protein change tendency,and the aim of this study was to explore distribution of dehydrins in cells and the relationship with degree of drought tolerance under water stress.The main results are as follows:1,At the initial stage of the water stress(4~8h), the golden particles were mainly distributed in the cytoplasm, and also with a small amount in the nucleus. During the interim of the treatment(12~24h), golden particles were mainly located in the cytoplasm and the nucleus, and also with a small amount in the organelle. At the end of the treatment(36~48h), most golden particles were detected nearby the plasmalemma. The golden particles in the cytoplasm and the nucleus were relatively more after 24 hours of the rehydration, golden particles were relatively decrease nearby the plasmalemma. The results of the study show that, the dehydration mainly distributed in the cytoplasm when the plant under short-term drought stress, with the extension of stress time, dehydration large concentration nearby the plasma membrane, Further explained that water stress can induce the expression of dehydrins and transportation to the plasma membrane.Using the normal leaf tissue without any treatment and dehydrated protein antibody as contrast, however, none was detected.It is shows that dehydration induced expression under water stress. Further analysis showed that before water stress 36 h the number of gold particles in cytoplasm more than nuclear in two varieties wheat,but the phenomenon contrary after 36 h, and it is shows dehydration expression in the cytoplasm preceded in the nucleus.2,Western bloting analysis showed that ,there was a specific protein of 37 kD under water stress and it did not appear during the normal water supply situation. With the increase of stress time, This protein band color gradually deepening, The results of the diversification show that, dehydrated protein expression increased gradually and disappeared after rehydration.Dehydration protein expression quantity in drought resistance stronger'ShanHe 6'higher than in drought resistance weaker'ZhengYin 1', and its expression was positively correlated with wheat drought tolerance. The results shows that the the dehydration protein expression is closely related with wheat drought resistance.3,With the increase of stress time, the membrane permeability increased at beginning. drought resistance stronger'ShanHe 6'lower than in drought resistance weaker'ZhengYin 1', The results shows its expression was positively correlated with wheat drought tolerance.4,With the increase of stress time,the results of the study show that,in'ShanHe 6'and'ZhengYin 1'the soluble protein content was also increased first and decreased later; after rewatering, relative permeability of cell soluble protein content was increased. Dehydrin protein in wheat-like are soluble proteins, but the experimental results shows that, the soluble protein content in'ShanHe 6'was lower than in'ZhengYin 1',and the changing trend were also opposite to dehydration protein. This dehydration protein stable the cellular structure at all levels of the organization and not only indicate the complexity of plant drought-resistance mechanism, but also reflects the characteristics of water stress-induced proteins and resists the correlation of dehydration ability.