title: Comparative proteomic study reveals the involvement of diurnal cycle in cell division, enlargement, and starch accumulation in developing endosperm of Oryza sativa.
abstract: The development and starch accumulation of cereal endosperms rely on the sugar supply of leaves, which is subject to diurnal cycles, and the endosperm itself also experiences a light/dark switch. However, revealing how the cereal endosperm responds to diurnal input remains a major challenge. We used comparative proteomic approaches to probe diurnally affected processes in rice endosperm (Oryza sativa) 10 days after flowering under 12-h light/12-h dark. Starch granules in rice endosperm showed a growth ring structure under a normal light/dark cycle but not under constant light. Sucrose showed a high level in light and low level in dark. Two-dimensional (2-D) differential in-gel electrophoresis-based proteomic analysis revealed 101 protein spots diurnally changed and 91 identities, which were involved in diverse processes with preferred distribution in stress response, protein synthesis/destination and metabolism. Proteins involved in cell division showed high expression in light and those in cell enlargement and cell wall synthesis high in dark, while starch synthesis proteins were light-downregulated and dark-upregulated. Redox homeostasis-associated proteins showed in-phase peaks under light and dark. These data demonstrate diurnal input-regulated diverse cellular and metabolic processes in rice endosperm, and coordination among these processes is essential for development and starch accumulation with diurnal input.
authors: Key Laboratory for Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100093, China.
authors: Hua Tao
authors: HT
authors: Yu
authors: Sheng Bao
authors: SB
authors: Xu
authors: Can Hui
authors: CH
authors: Zheng
authors: Tai
authors: T
authors: Wang
mesh_terms: D050260:Carbohydrate Metabolism; D002455:Cell Division; D049108:Cell Enlargement; D002940:Circadian Rhythm; D016000:Cluster Analysis; D056625:Endosperm / Q000166:cytology / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D012275:Oryza / Q000166:cytology / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D010446:Peptide Fragments / Q000737:chemistry; D010449:Peptide Mapping; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D020543:Proteome / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics; D013213:Starch / Q000378:metabolism* / Q000648:ultrastructure; D014158:Transcription, Genetic
chemical_list: D010446:Peptide Fragments; D010940:Plant Proteins; D020033:Protein Isoforms; D020543:Proteome; D013213:Starch