Proteomic Analysis Of Chromium Stress-responsive Proteins In Thellungiella Halophila

Chromium has become one of the main soil pollutants in China recently,affecting plants' growth and development seriously,especially for crops' production that caused greater damage,while chromium by the food chain to eventually into the human body and is harmful to health.Although people try to use a variety of different ways to control heavy metal pollution,but has a little success,which has become a problem in the whole of China even the world.In order to better study the response of plants under specific environmental conditions,people found that Thellungiella halophila can be used as a model for the relevant experimental study,that can tolerate the degree of drought,high salt and low temperature stress,and in the long process of evolution in the formation of a specific response to the ecological mechanism of stress,through the response to stress tolerance of proteogics research,help us understand the plant resistance molecular mechanism,the future further through molecular breeding means to improve plant resistance has important significance.To intensive study the adverse effects of plants in harsh environments,proteomics scientific analyzes the proteins produced by the expression of plants under different conditions,and explores their different mechanisms of reaction,which will deepen the understanding and understanding of these microscopic molecular levels and to further enhance the growth of plants in different environments ability,and provides theo-retical guidance.In this paper,the physiological and biochemical analysis of Thellungiella halophila under heavy metal chromium stress and the comparative proteomics study were carried out to reveal the molecular mechanism of plant response to chromium stress and the molecular mechanism of plant tolerance to chromium stress.As the consequences as follows:1.Effects of chromium stress on growth and physiological indicators of Thellungiella halophilaThe results showed that 250 mg/L K2Cr2O7 solution had obvious chromium stress phenotype,but it can be survived.In the next experiment,250 mg/L of K2Cr2O7 solution as a chromium stress treatment.The morphological changes of the seedlings were observed at 0 h,1 h,6 h,24 h and 48 h,respectively.The morphological changes of the seedlings were observed at the time of 0 h,1 h,6 h,24 h and 48 h,respectively.The effects of chromium content and relative conductivity metal leakage(REL),proline and other physiological indicators.The content of chromium in the leaves of Thellungiella halophila increased gradually with the increase of treatment time,reached the maximum at 48 h(343.0 mg/kg).The REL was higher than the control group in the leaves of Thellungiella halophila,but it did not have a evident diversification.The content of proline in Thellungiella halophila was decreased significantly after 6 h(p<0.05).After 48 h,the content of proline became the highest(p<0.01).The results showed that,with the prolongation of chromium stress treatment time,chromium accumulated in Thellungiella halophila,and it responded to the leaf water stress caused by chromium stress,which can be achieved by protecting the cell structure of leaves and increasing the proline content in leaves.2.Proteomic analysis of leaves in Thellungiella halophila under chromium stressThe total proteins of Thellungiella halophila before and after the treatment was analyzed by 2-DE,and there were about 1200 protein spots dissociated repeatedly.The mage Master 2D Platinum7.0 software was used to analyze the electrophoretic gel and found that 61 different protein spots(Ratio?1.5,Anova p<0.05).Among them,18 protein spots were down-regulated at 1 h,6 h,24 h and 48 h,and 7 protein spots were up-regulated at 1h,6h,24 h and 48 h,among which 18 protein spots,the expression level was up-regulated at a certain time point and was down-regulated at another time point.By MALDI-TOF/TOF mass spectrometry,there were 43 proteins(70.5%)identified successfully.These differential proteins are projected to take part in the biological process,and on the basis of their distinct functions are classified to 7 categories.Category 1: protein synthesis,folding and degradation(23%);category 2: photosynthesis and chloroplast organization(18.5%);category 3: redox homeostasis and response(18.5%);category 4: sugar,lipid and other metabolic processes(16%);category 5: stress and defense response(14%);category 6: RNA regulation and transport(5%);category 7: proton transport(5%).Some of these different proteins responsing to stress which have been identified,and more than half of the proteins are involved in protein synthesis,folding and degradation,photosynthesis and chloroplast organization,redox reactions and response,metabolites(sugars,lipids,etc.),suggesting that the above-mentioned proteins in the biological processes may play a key role in Thellungiella halophila response to chromium stress.