Metabolism of nicotinamide, adenine and inosine in developing microspore-derived canola (Brassica napus) embryos
The metabolic fate of [carbonyl-(14)C]nicotinamide, [8-(14)C]adenine and [8-(14)C]inosine was examined in microspore-derived canola (Brassica napus) embryos at different developmental stages: globular stage (day 10, stage 1), early cotyledonary stage (day 20, stage 2), late cotyledonary stage (day 2...
| Veröffentlicht in: | Plant physiology and biochemistry : PPB. - 1991. - 46(2008), 8-9 vom: 15. Aug., Seite 752-9 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | Plant physiology and biochemistry : PPB |
| Schlagworte: | Journal Article Carbon Radioisotopes RNA, Plant NAD 0U46U6E8UK Niacinamide 25X51I8RD4 Niacin 2679MF687A NADP mehr... |
| Zusammenfassung: | The metabolic fate of [carbonyl-(14)C]nicotinamide, [8-(14)C]adenine and [8-(14)C]inosine was examined in microspore-derived canola (Brassica napus) embryos at different developmental stages: globular stage (day 10, stage 1), early cotyledonary stage (day 20, stage 2), late cotyledonary stage (day 25, stage 3), and fully developed stage (day 35, stage 4). Uptake of [8-(14)C]nicotinamide by the embryos was always rapid. A lower uptake rate was found for [8-(14)C]adenine and [8-(14)C]inosine, especially at stages 1 and 2. [Carbonyl-(14)C]nicotinamide was converted to nicotinic acid and further metabolized to pyridine nucleotides (NAD/NADP). Some radioactivity was also associated to nicotinic acid glucoside. [8-(14)C]adenine was efficiently utilized for the synthesis of adenine nucleotides and RNA. A small fraction of adenine was degraded to CO(2) via ureides. Up to 40% of [8-(14)C]inosine was salvaged to nucleotides and RNA, although degradation of [8-(14)C]inosine to CO(2) was pronounced. At stage 1, highest salvage activities of nicotinamide, adenine and inosine were observed. In contrast, the lowest purine salvage and highest purine catabolism were found in stage 3 embryos. These results suggest that both nicotinamide and purine salvage for NAD/NADP and purine nucleotides synthesis are extremely high in the globular stage (stage 1). These activities decrease gradually until the late cotyledonary stage (stage 3), before increasing again in the fully developed embryos (stage 4). Overall it appears that nicotinamide and purine salvage are required in support of active growth during the initial phases of embryogenesis and at the end of the maturation period, in preparation for post-embryonic growth |
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| Beschreibung: | Date Completed 06.10.2008 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 0981-9428 |
| DOI: | 10.1016/j.plaphy.2008.04.013 |