| Plants are frequently facing different environmental variations.Among these constraints, low temperature is one of the most crucial abiotic stress limiting the plant growth and the plant geographical distribution.With the development of molecular mechanism and biotechnology on plant cold stress, using biotechnologies and transgenic strategies to improve stresss tolerance is supplied another way to cultivate new stress plants.In recent years,the methods and technologies of proteomics are applied to plant research and have acquired many useful results. Proteomic approach is a powerful tool to study plant stress responses.The systemsatic proteome approaches have been adopted to study the molecular mechanism of plant in responses to low temperature stress and to discover cold responsive proteins,which paved the way for improving the resistance of the plant to low temperature stress.In this paper, To investgate how buffalograss,a type of warmsean grasses , adapts to cold stress.We have compared control with treated seedings with respect to several physiological parameters and changes in leaf protein expression by using two-dimensional gel electrophoresis(2-DE), mass spectrometry(MS), and bioinformatics analyses. Four-week-old seedlings were respectively exposed to low temperature at 5℃for 6h﹑24h respectively.Though the changes of physiological and proteins of buffalograss under low temperature,and many cold responsive proteins identified by MS, the resistance mechanism of the plant to low temperature stress was discussed,which can provide many preliminary theothy for cultivating new bussalograssess and can conduct practices during cold stress.The results were summarized as follows:1 The leaf cell membrane of buffalograss seedlings subjected to a certain degree of damage under low temperature stress. And the longer the stress time is, the greater the damage, the greater the relative conductivity. Under a certain stress, the leaf cell membrane would not be caused permanent damage.2 With the extension of the stress time, SOD, POD and CAT activity in buffalograss leaves increased at the early of low temeperature stress and decreased at end. Change still has its own characteristics .Compared to control POD activity changed significantly. When the stress lasted until 24 h, POD activity decreased and almost flatted compared with the control, this showed that POD activity was sensitive to the low temperature stress. Changes of CAT and SOD activity were in the line, the results indicated that activity of two enzymes coordinated the regulation of low-temperature adaptation.3 Total proteins were extracted from the leaves collected from both control and treated seedlings leaves using Trizol precipitation and then separated by two-dimensional gel electrophoresis (2-DGE). Approximately 850 protein spots were separated and visualized on silver stained 2-D gels. Using ImageMaster 2D Platinum V 5.0 analing,wherein 87 protein spots were differentially expressed at least at one time point.60 protein spots were found to be up-regulated and 27 protein spots were down-regulated under low temperature treated.4 26 protein spots which changed significantly were selected to be identified using the analysis of MALDI-TOF mass spectrometry or ESI MS/MS.MALDI-TOFMS analysis,17protein spots have successfully identified.The identified proteins mainly participated in signal transduction,protein processing,redox homeostasis ,and the metabolisms of carbon,energy,sulfur and fat acid . The identification of two novel proteins in the cold stress resonse provides new insights that can lead a better understanding of molecular basis of cold-sensitivity in plant. |
PDF Full Text Request