著者

和田 七夕子 勝見 允行

出版者

植物化学調節学会

雑誌

植物化学調節学会研究発表記録集 (ISSN:09191887)

巻号頁・発行日

no.35, pp.85-86, 2000-11-02

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From the 7th internodes of light-grown seedlings of LKB pea (wild type) and 1kb dwarf pea, a brassinolide (BR) deficient mutant, upper 8 mm segments were excised and stored in 50% glycerol at -15C for more than 2 weeks. The extensibility (φ) and the yield threshold (y) of the cell wall were analyzed by creep measurements of these glycerinated segments (G-segments). LKB had higher φ and lower y values than lkb in response to acidity (pH4.5). However, G-segments taken from BR-treated 1kb seedlings had φ and y values similar to those of LKB. On the other hand, G-segments of LKB taken from seedlings treated with brassinazole (BZ), an inhibitor of BR biosynthesis, had higher y values than non-treated LKB. When G-segments of lkb were incubated with BR for 1 hr and then creep measurements were made in the presence of BR, their φ and y values were also similar to those of LKB. Heat treatment of G-segments diminished their ability to respond to acidity. Addition of a crude cell wall protein fraction to heat-treated LKB G-segments could restore their ability. In the case of heat-treated 1kb and LKB pretreated with BZ, their ability could be restored only in the presence of BR. These results suggest that BR is necessary for acid-induced cell wall loosening possibly as an effector of cell wall enzymes responsible for φ and y changes.