Function of silica bodies in the epidermal system of rice (Oryza sativa L.): testing the window hypothesis

• Published in: Journal of experimental botany 1996-05, Vol.47 (5), p.655-660
• Main Authors: Agarie, Sakae, Agata, Waichi, Uchida, Hideki, Kubota, Fumitake, Kaufman, Peter B.
• Format: Article
• Language: English
• Subjects: Absorptance; Agronomy. Soil science and plant productions; Biological and medical sciences; Carbon Dioxide - metabolism; Economic plant physiology; Energy consumption; Epidermal cells; Fundamental and applied biological sciences. Psychology; Leaves; Light; Metabolism; Microscopy, Electron, Scanning; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; Optical properties; optical property; Optical reflection; Oryza - cytology; Oryza - drug effects; Oryza - physiology; Oryza - ultrastructure; Photochemistry; Photons; Photosynthesis - drug effects; Photosynthesis - radiation effects; Photosynthesis, respiration. Anabolism, catabolism; Plant Epidermis - physiology; Plant Leaves - cytology; Plant Leaves - drug effects; Plant Leaves - physiology; Plant Leaves - ultrastructure; Plant physiology and development; Plants; quantum yield; Research Papers; Rice; Silicon; Silicon - pharmacology; Silicon - physiology; Silicon Dioxide - pharmacology; Space life sciences; Spectral reflectance; window hypothesis
• ISSN: 0022-0957; 1460-2431
• DOI: 10.1093/jxb/47.5.655

Silicon has been considered to be important for normal growth and development of the rice plant (Oryza sativa L.). To investigate the physiological function of deposited silica in rice leaves, the hypothesis that silica bodies in the leaf epidermal system might act as a ‘window’ to facilitate the transmission of light to photosynthetic mesophyll tissue was tested. The silica content of leaves increased with supplied silicon and was closely correlated with the number of silica bodies per unit leaf area in the epidermal system. There was a significant difference in silica deposition and formation of silica bodies between Si-treated and non-treated leaves; silicon was polymerized inside the silica cells and bulliform cells of the epidermis, in Si-treated leaves. Although the ‘windows’ were only formed in leaves with applied silicon, optical properties of leaf transmittance, reflectance and absorptance spectra in Si-treated and non-treated leaves were almost equal. Furthermore, light energy use efficiency and quantum yield of Si-treated leaves were less than in leaves not containing silica bodies. Thus, silica bodies, at least based on the data, do not function as windows in rice leaves.