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l-Ascorbic Acid Metabolism in Vitaceae: Conversion to (+)-Tartaric Acid and Hexoses
1Department of Biology, State University of New York at Buffalo, Buffalo, New York 14214.
Plant Physiology
|November 1, 1974
Summary
Ascorbic acid metabolism in Vitaceae plants involves breaking down its carbon chain. This process leads to tartaric acid formation and recycling into energy pathways, distinct from other known tartaric acid biosynthesis routes.
Area of Science:
- Plant biochemistry
- Metabolic pathways
- Organic acid biosynthesis
Background:
- Ascorbic acid (vitamin C) is vital in plant metabolism.
- The biosynthesis of tartaric acid in plants is not fully understood.
- Vitaceae family plants are known for accumulating organic acids.
Purpose of the Study:
- To investigate the metabolic fate of l-ascorbic acid in Vitaceae species.
- To elucidate the specific pathways of tartaric acid formation in these plants.
- To compare ascorbic acid metabolism in Vitaceae with other tartaric acid accumulating plants.
Main Methods:
- Utilized radiolabeled l-ascorbic acid (1-(14)C and 6-(14)C) tracers.
- Studied metabolic pathways in two species from two genera of Vitaceae.
- Analyzed the breakdown products and their subsequent metabolic fates.
Main Results:
- Ascorbic acid metabolism in Vitaceae involves cleaving the 6-carbon chain into 4- and 2-carbon fragments.
- The 4-carbon fragment (C1-C4) is oxidized to tartaric acid.
- The 2-carbon fragment (C5-C6) is recycled into hexose phosphate metabolism.
Conclusions:
- Vitaceae plants possess a unique pathway for tartaric acid biosynthesis from ascorbic acid.
- This pathway differs from the previously identified conversion in Pelargonium crispum.
- The findings highlight distinct mechanisms of tartaric acid accumulation in plants.
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