Developing prolamine protein bodies are associated with the cortical cytoskeleton in rice endosperm cells

• Published in: Planta Vol. 211; no. 2; pp. 227 - 238
• Main Authors: Muench, Douglas G., Chuong, Simon D. X., Franceschi, Vincent R., Okita, Thomas W.
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01.07.2000; Springer
• Subjects: Animal cells; Biological and medical sciences; Cell biochemistry; Cell membranes; Cell physiology; Corn; Cytoskeleton; Cytoskeleton - physiology; Cytoskeleton - ultrastructure; Endosperm; Fluorescent Antibody Technique, Indirect; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Plant; Messenger RNA; Microfilaments; Microscopy, Confocal; Microtubules; Organelles - physiology; Organelles - ultrastructure; Oryza - cytology; Oryza - growth & development; Oryza - physiology; Plant cells; Plant physiology and development; Plant Proteins - biosynthesis; Plant Proteins - genetics; Prolamins; Rice; RNA, Messenger - metabolism; Monocotyledones; Storage protein; Microfilament; Biosynthesis; Cereal crop; Oryza sativa; Messenger RNA; Gramineae; Ultrastructure; Actin; Angiospermae; Cytoskeleton; Spermatophyta; Endosperm; Microtubule; Localization; Prolamin; Protein body
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/PL00008159

The mRNAs that encode the prolamine storage proteins in rice (Oryza sativa L.) endosperm cells are enriched on the surface of the prolamine protein bodies (PBs), a subcellular structure consisting of a prolamine intracisternal granule surrounded by rough endoplasmic reticulum membrane. Previous biochemical studies (D.G. Muench et al., 1998, Plant Physiol. 116: 559— 569) have shown that prolamine mRNAs may be anchored to the PB surface via the cytoskeleton. To better understand the mechanism and role of mRNA localization in rice endosperm cells, we studied the subcellular development of prolamine PBs and their relationship with the cytoskeleton in rice endosperm cells. Confocal microscopy of endosperm cells showed that, unlike the glutelin PBs, the developing prolamine PBs are not randomly distributed within the cell, but instead are often enriched in the cortical region of the cell only a few micrometers beneath the plasma membrane. In addition, the peripheral prolamine PBs are closely associated with the cortical microtubule and actin filament networks. The cortical enrichment of rice prolamine protein bodies represents a unique example of endoplasmic reticulum subdomain localization in plant cells. The interaction of this endoplasmic reticulum subdomain with the cytoskeleton provides new insights on the possible mechanism and role of mRNA localization in plants.