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Temperature modulates the cell wall mechanical properties of rice coleoptiles by altering the molecular mass of hemicellulosic polysaccharides
Author(s) -
Nakamura Yukiko,
Wakabayashi Kazuyuki,
Hoson Takayuki
Publication year - 2003
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.2003.00144.x
Subject(s) - coleoptile , cell wall , polysaccharide , extensibility , oryza sativa , chemistry , biophysics , molecular mass , botany , biochemistry , biology , enzyme , computer science , gene , operating system
The present study was conducted to investigate the mechanism inducing the difference in the cell wall extensibility of rice ( Oryza sativa L. cv. Koshihikari) coleoptiles grown under various temperature (10–50°C) conditions. The growth rate and the cell wall extensibility of rice coleoptiles exhibited the maximum value at 30–40°C, and became smaller as the growth temperature rose or dropped from this temperature range. The amounts of cell wall polysaccharides per unit length of coleoptile increased in coleoptiles grown at 40°C, but not at other temperature conditions. On the other hand, the molecular size of hemicellulosic polysaccharides was small at temperatures where the cell wall extensibility was high (30–40°C). The autolytic activities of cell walls obtained from coleoptiles grown at 30 and 40°C were substantially higher than those grown at 10, 20 and 50°C. Furthermore, the activities of (1→3),(1→4)‐ β ‐glucanases extracted from coleoptile cell walls showed a similar tendency. When oat (1→3),(1→4)‐ β ‐glucans with high molecular mass were incubated with the cell wall enzyme preparations from coleoptiles grown at various temperature conditions, the extensive molecular mass downshifts were brought about only by the cell wall enzymes obtained from coleoptiles grown at 30–40°C. There were close correlations between the cell wall extensibility and the molecular mass of hemicellulosic polysaccharides or the activity of β ‐glucanases. These results suggest that the environmental temperature regulates the cell wall extensibility of rice coleoptiles by modifying mainly the molecular mass of hemicellulosic polysaccharides. Modulation of the activity of β ‐glucanases under various temperature conditions may be involved in the alteration of the molecular size of hemicellulosic polysaccharides.