title: Comparative proteomics analysis reveals an intimate protein network provoked by hydrogen peroxide stress in rice seedling leaves.
abstract: Hydrogen peroxide (H2O2) plays a dual role in plants as the toxic by-product of normal cell metabolism and as a regulatory molecule in stress perception and signal transduction. However, a clear inventory as to how this dual function is regulated in plants is far from complete. In particular, how plants maintain survival under oxidative stress via adjustments of the intercellular metabolic network and antioxidative system is largely unknown. To investigate the responses of rice seedlings to H2O2 stress, changes in protein expression were analyzed using a comparative proteomics approach. Treatments with different concentrations of H2O2 for 6 h on 12-day-old rice seedlings resulted in several stressful phenotypes such as rolling leaves, decreased photosynthetic and photorespiratory rates, and elevated H2O2 accumulation. Analysis of approximately 2000 protein spots on each two-dimensional electrophoresis gel revealed 144 differentially expressed proteins. Of them, 65 protein spots were up-regulated, and 79 were down-regulated under at least one of the H2O2 treatment concentrations. Furthermore 129 differentially expressed protein spots were identified by mass spectrometry to match 89 diverse protein species. These identified proteins are involved in different cellular responses and metabolic processes with obvious functional tendencies toward cell defense, redox homeostasis, signal transduction, protein synthesis and degradation, photosynthesis and photorespiration, and carbohydrate/energy metabolism, indicating a good correlation between oxidative stress-responsive proteins and leaf physiological changes. The abundance changes of these proteins, together with their putative functions and participation in physiological reactions, produce an oxidative stress-responsive network at the protein level in H2O2-treated rice seedling leaves. Such a protein network allows us to further understand the possible management strategy of cellular activities occurring in the H2O2-treated rice seedling leaves and provides new insights into oxidative stress responses in plants.
authors.affiliation: Laboratory of Molecular Biology and Protein Science Laboratory of the Ministry of Education, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, China.
authors.forename: Xiang-Yuan
authors.initials: XY
authors.lastname: Wan
authors.forename: Jin-Yuan
authors.initials: JY
authors.lastname: Liu
mesh_terms: D015180:Electrophoresis, Gel, Two-Dimensional; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D012275:Oryza / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology; D018515:Plant Leaves / Q000737:chemistry / Q000187:drug effects / Q000502:physiology; D010940:Plant Proteins / Q000032:analysis*; D020543:Proteome / Q000032:analysis*; D036226:Seedlings / Q000737:chemistry / Q000187:drug effects / Q000502:physiology; D053719:Tandem Mass Spectrometry
chemical_list: D010940:Plant Proteins; D020543:Proteome; D006861:Hydrogen Peroxide