Comparative Proteomic Study Reveals the Involvement of Diurnal Cycle in Cell Division, Enlargement, and Starch Accumulation in Developing Endosperm of Oryza sativa

• Published in: Journal of proteome research Vol. 11; no. 1; pp. 359 - 371
• Main Authors: Yu, Hua Tao, Xu, Sheng Bao, Zheng, Can Hui, Wang, Tai
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01.01.2012
• Subjects: Carbohydrate Metabolism; Cell Division; Cell Enlargement; cell growth; cell walls; Circadian Rhythm; Cluster Analysis; diurnal variation; endosperm; Endosperm - cytology; Endosperm - growth & development; Endosperm - metabolism; Endosperm - physiology; flowering; Gene Expression Profiling; Gene Expression Regulation, Plant; leaves; Oryza - cytology; Oryza - growth & development; Oryza - metabolism; Oryza - physiology; Oryza sativa; Peptide Fragments - chemistry; Peptide Mapping; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Protein Isoforms - genetics; Protein Isoforms - metabolism; protein synthesis; proteins; proteome; Proteome - chemistry; Proteome - genetics; Proteome - metabolism; Proteomics; rice; seed development; Starch - metabolism; Starch - ultrastructure; starch granules; stress response; sucrose; Transcription, Genetic; Oryza sativa; starch; comparative proteomics; diurnal cycle; endosperm
• ISSN: 1535-3893; 1535-3907; 1535-3907
• DOI: 10.1021/pr200779p

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.