title: Proteomic analysis of endoplasmic reticulum stress responses in rice seeds.
abstract: The defects in storage proteins secretion in the endosperm of transgenic rice seeds often leads to endoplasmic reticulum (ER) stress, which produces floury and shrunken seeds, but the mechanism of this response remains unclear. We used an iTRAQ-based proteomics analysis of ER-stressed rice seeds due to the endosperm-specific suppression of OsSar1 to identify changes in the protein levels in response to ER stress. ER stress changed the expression of 405 proteins in rice seed by >2.0- fold compared with the wild-type control. Of these proteins, 140 were upregulated and 265 were downregulated. The upregulated proteins were mainly involved in protein modification, transport and degradation, and the downregulated proteins were mainly involved in metabolism and stress/defense responses. A KOBAS analysis revealed that protein-processing in the ER and degradation-related proteasome were the predominant upregulated pathways in the rice endosperm in response to ER stress. Trans-Golgi protein transport was also involved in the ER stress response. Combined with bioinformatic and molecular biology analyses, our proteomic data will facilitate our understanding of the systemic responses to ER stress in rice seeds.
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Qian
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Tian
authors.affiliation: Key Laboratory of Plant Molecular Physiology, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Leqing
authors.initials: L
authors.lastname: Qu
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics; D050260:Carbohydrate Metabolism / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000502:physiology; D059865:Endoplasmic Reticulum Stress / Q000235:genetics* / Q000502:physiology; D056625:Endosperm / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D050886:HSP20 Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics; D012275:Oryza / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000235:genetics; D017510:Protein Folding; D021381:Protein Transport / Q000235:genetics*; D040901:Proteomics; D055314:Seed Storage Proteins / Q000235:genetics*; D012639:Seeds / Q000378:metabolism; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: D048948:14-3-3 Proteins; D050886:HSP20 Heat-Shock Proteins; D055314:Seed Storage Proteins