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Are polyamines transported in etiolated peas?
1Department of Biology, Yale University, New Haven, Connecticut 06511.
Plant Physiology
|December 1, 1983
Summary
Polyamines in pea seedlings likely originate from transported amino acids, not direct polyamine transport. This study shows amino acid precursors are converted into polyamines in growing regions.
Area of Science:
- Plant Physiology
- Biochemistry
Background:
- Polyamines are crucial for plant growth and development.
- The origin and transport of polyamines in seedlings remain an area of investigation.
Purpose of the Study:
- To investigate the transport and metabolic fate of polyamines and their amino acid precursors in pea seedlings.
- To determine if polyamines are transported directly or synthesized from precursors.
Main Methods:
- (14)C-labeled putrescine, spermidine, arginine, and lysine were injected into etiolated pea seedling cotyledons.
- Radioactivity in shoots, roots, and cotyledons was quantified after 4 hours.
- Extracted polyamines were dansylated and separated using thin-layer chromatography.
Main Results:
- Direct transport of labeled putrescine or spermidine from cotyledons was minimal.
- Significant radioactivity transport into the seedling axis occurred with labeled arginine and lysine.
- A substantial portion of transported radioactivity from amino acids was recovered as polyamines (putrescine or cadaverine).
Conclusions:
- Polyamines in growing regions of etiolated pea seedlings are likely synthesized from transported amino acid precursors.
- Direct transport of pre-formed polyamines is not a major pathway in this developmental stage.