title: Growth promotion and an increase in cell wall extensibility by silicon in rice and some other Poaceae seedlings.
abstract: The effect of silicon on organ growth and its mechanisms of action were studied in rice ( Oryza sativa L. cv. Koshihikari), oat ( Avena sativa L. cv. Victory), and wheat ( Triticum aestivum L. cv. Daichino-Minori) seedlings grown in the dark. Applying silicon in the form of silicic acid to these seedlings via culture solution resulted in growth promotion of third (rice) or second (oat and wheat) leaves. The optimal concentration of silicon was 5-10 mM. No growth promotion was observed in early organs, such as coleoptiles or first leaves. In silicon-treated rice third leaves, the epidermal cell length increased, especially in the basal regions, without any effect on the number of cells, showing that silicon promoted cell elongation but not cell division. Silicon also increased the cell wall extensibility significantly in the basal regions of rice third leaves. These results indicate that silicon stimulates growth of rice and some other Poaceae leaves by increasing cell wall extensibility.
authors.affiliation: Department of Biology, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Mohammad Talim
authors.initials: MT
authors.lastname: Hossain
authors.forename: Ryuji
authors.initials: R
authors.lastname: Mori
authors.forename: Kouichi
authors.initials: K
authors.lastname: Soga
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Wakabayashi
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Kamisaka
authors.forename: Shuhei
authors.initials: S
authors.lastname: Fujii
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hoson