| Hydrogen peroxide(H2O2),as one of reactive oxygen species(ROS),plays essential roles in mediating a variety of developmental processes.The content of H2O2 increases in respond to a variety of biotic and abiotic stimuli,which not only leads to oxidative damage to protein,DNA and lipid,but can also function as signals to regulate signaling pathways and gene expressions.In this study,membrane permselectivity,antioxidant enzymes activity,as well as the contents of osmolytes,ROS and antioxidants under H2O2 stress(0mM?12 mM?24 mM and 36 mM)were investigated.Meanwhile,92 differentially abundant protein spots were identified to match 66 differentially abundant proteins by high throughput proteomics technology.The results indicated that the cell integrity was destroyed,the content of osmolytes increased,and defense-related enzymes activity increased by H2O2 stress after 6 h in the leaves of Puccinellia tenuiflora.These identified proteins are involved in various cellular responses and metabolic processes with obvious functional tendencies toward photosynthesis,carbohydrate/energy metabolism,protein synthesis and stress related processes.Proteomics results revealed the specific H2O2-responsive strategies existed in P.tenuiflora leaves.The main strategies include:(1)the abundance of chlorophyll binding proteins/light-harvesting complexs decreased,iron-sulfur protein and ferredoxin-NADP(H)oxidoreductase abundance changed,light-harvesting process and the electron transfer process was suppressed;(2)the abundance of proteins involved in the Calvin cycle increased,indicates that the promoted Calvin cycle was beneficial to carbon fixation;(3)the abundance of protein synthesis associated proteins were decreased,but the proteins involved in RNA processing and protein processing played their function and response to H2O2 stress actively.This provided more important imformation for further underlying the fine-tuned signaling and metabolic networks and regulative mechanisms in P.tenuiflora leaves. |
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