ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
The metabolism of organic dormancy-breaking chemicals is poorly defined and may provide clues to their mode of action. Therefore, hydrated, dormant seeds of red rice (Oryza sativa L.) were exposed to dormancy-breaking treatments of propionate-2-13C (22 mW) or propanol-1-13C (75 mM) for 24 h at 30°C. Embryo extracts were analyzed by 13C-nuclear magnetic resonance spectroscopy. Metabolism of propionate and propanol to 3-hydroxypropionate, an intermediate of the modified β-oxidation pathway, was detected after 2 and 4 h, respectively. This occurred prior to the onset of dormancy-breaking which required 12 h of chemical exposure. Accumulation of 3-hydroxypropionate was rapid and linear in the embryos of propionate-treated seeds. In the embryos of propanol-treated seeds, the level of 3-hydroxypropionate reached a plateau at 4 h. Following 24 h of contact with propionate, labeled citrate was detected in the embryos. The decrease in tissue pH associated with the dormancy-breaking process was fully accounted for by direct acid uptake and metabolic production of 3-hydroxypropionate.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1995.tb00982.x
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