title: Gel-based comparative phosphoproteomic analysis on rice embryo during germination.
abstract: Seed germination is a well regulated process, which incorporates many events including signal transduction, mobilization of reserves, reactive oxygen species scavenging and cell division. Although many transcriptomic and proteomic studies have been conducted on this process, regulation of protein modification has not been studied. To better understand the mechanism, a gel-based comparative phosphoproteomic study was performed on rice embryo during the germination process. In total, 168 protein spots exhibited significantly changed Pro-Q staining intensity during germination. Using matrix-assisted laser deionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF MS) analysis, 193 proteins were identified. By combining Pro-Q and Coomassie brilliant blue stain intensity analyses, 109 proteins were verified to be phosphorylation regulation proteins. Functional analyses indicated that phosphorylation of proteins involved in stress response and storage was gradually enhanced. Phosphorylation of signal transduction proteins was mainly activated during the early stage of germination, while stress response and storage protein phosphorylation were enhanced at the late stage. Enzyme assays proved that the phosphorylation of fructokinase, pyruvate kinase, malate dehydrogenase, GDP-mannose 3,5-epimerase1, ascorbate peroxidase and glutathione S-transferase could consistently enhance their activity. This study showed the dynamic changes of protein phosphorylation status in rice embryo during germination and provided new insight into understanding the mechanism underlying this process.
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuchang Moshan, Wuhan 430074, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Han
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuchang Moshan, Wuhan 430074, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuchang Moshan, Wuhan 430074, China yangpf@wbgcas.cn.
authors.forename: Pingfang
authors.initials: P
authors.lastname: Yang
mesh_terms: D015180:Electrophoresis, Gel, Two-Dimensional; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018525:Germination; D053858:Metabolic Networks and Pathways; D012275:Oryza / Q000254:growth & development / Q000378:metabolism*; D010766:Phosphorylation; D010940:Plant Proteins / Q000145:classification / Q000378:metabolism*; D040901:Proteomics; D012639:Seeds / Q000254:growth & development / Q000378:metabolism*; D015398:Signal Transduction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
chemical_list: D010940:Plant Proteins
keywords: Embryo; Germination; Phosphoproteomics; Rice