ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
Citrus (Citrus sinensis L. Osbeck) leaf explants completely abscise within 48 h when exposed to saturating amounts of ethylene at 25°C. When 2,5-norbornadiene was added, 2000 μl 1−1 reduced abscission of explants also exposed to 2 μl 1−1 of ethylene to the level of the control, and 8000 μl 1−1 reduced abscission in explants exposed to 10 μl 1−1 of ethylene to the level of the control, but abscission was complete when 1 000 μl 1−1 of ethylene was used in the presence of 8 000 μl 1−1 of 2,5-norbornadiene. When explants were exposed to 2 μl 1−1 of ethylene, 2000 μl 1−1 of 2,5-norbornadiene prevented abscission if applied up to 10 h after exposure to ethylene. After 18 h, applied 2,5-norbornadiene had little effect on abscission at 48 h. A Lineweaver-Burk plot gave a 1/2 maximum value of 0.12 μl 1−1 for ethylene on abscission, 2,5-Norbornadiene gave competitive kinetics with respect to ethylene with a K1 value of approximately 120 μl 1−1 of 2,5-norbornadiene. The presence of 2,5norbornadiene stimulated ethylene production, which progressively increased as the 2,5-norbornadiene concentration was increased from 250 to 8 000 μl 1−1 2,5-Norbornadiene also suppressed the induction of cellulase and polygalacturonase by ethylene. Together, 2,5-norbornadiene and 2,4-dichlorophenoxyacetic acid were more effective than either alone in reducing abscission. 2,5-Norbornadiene also was effective in preventing the reduction of indole-3-acetic acid transport induced by ethylene.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1985.tb02828.x
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