研究生文献汇报.ppt

Fast responses of metabolites in Vicia Fast responses of metabolites in Vicia faba L. to moderate NaCl stressfaba L. to moderate NaCl stressChristoph-Martin GeilfusPlant Physiology and Biochemistry2014Impact Factor 2.756目 录010102020303IntroductionIntroductionMethodsResultsDiscussion0 04 4IntroductionIntroduction强调文本内容强调文本内容The novelty of this study is the demonstration of complex stress-induced metabolic changes at the very beginning of a moderate salt stress in V. faba（15-90min）, information that are very scant for this early stage.This study reports for the first that the proline analogue trans-4-hydroxy-L-proline, known to inhibit cell elongation, was increasingly synthesized after NaCl-stress initiation.A reduced glutamine synthetase activity indicated that disturbances in the nitrogen assimilation occur earlier than it was previously thought under salt stress.This study was created with the focus on very fast metabolomic responses that ensue during the initiation period of salt stress,secondly metabolomic responses were not only investigated in the above ground tissue but also in the roots. MethodsMethods1.Cultivation of plant materialFaba bean (V. faba L.) of the minor cultivar Scirocco (Saaten-Union GmbH , Isernhagen, Germany) were grown hydroponically in a climate chamber(14/10 h day/night; 20/15; 50/80% humidity).2.Experimental set up and samplingLeaves (without petioles) and roots were sampled in liquid nitrogen before (0 min) and after (15, 30, 45, 60, 75, 90 min) the addition of 50 mM NaCl to the nutrient solution. 3.Metabolite extraction4.GC-MS analysis of metabolites5.Statistic evaluation of metabolite profile(PCA)6.Photosynthesis rate7.Sodium and chloride concentration8.Monitoring reactive oxygen species with OxyBURST dye9.Glutamine synthetase activityL-2-aminoadipate,L-alanine,L-aspartate,L-methionine,L-proline,L-serine,melibiose,pyruvate,spermidine,urea,glycerol-3-phosphate,trans-4-hydroxy-L-proline. Based on this PCA, the most relevant metabolites, 19 in number, were selected for a further individual analysis. They are:2-oxoglutarate,D- gluconic acid,ethanolamine,glycine,inositol-1-phosphate,isocitrate,Fig1ResultsResults1.Metabolite responses in root and leaf tissue upon the initiation of the salt stress2.Photosynthetic response3.Leaf sodium and chloride concentration4.ROS production5.Glutamine synthetase activityFig 2Fig 2Table 1Table 1Fig 3Fig 3Fig 4Fig 545Fig 6DiscussionDiscussion1. Fast responses of metabolites to salinity are different from long term responses.2. Changes in leaf metabolites associated with the generation and scavenging of reactive oxygen species (ROS) together with the oxidation of the fluorogenic ROS sensorOxyBURST Green H2HFF suggest excessive ROS formation in this early phase.3.Information on metabolic changes at early stages of salt stress is scant, regardless of the fact that salinity reduces biomass and yield formation. This study reports for the first that the proline analogue trans-4-hydroxy-L-proline that is known to inhibit cell elongation growth (Cleland, 1967)increased 60 min after NaCl stress initiation.4.The reduced glutamine synthetase activity together with an accumulation of glutamate indicate that disturbances in the nitrogen assimilation occur earlier than it was previously thought under salt stress. Fig 7THANKSTHANKS