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Assaying Proteasomal Degradation in a Cell-free System in Plants
Published on: March 26, 2014
Polyamine-induced DNA Synthesis and Mitosis in Oat Leaf Protoplasts
R Kaur-Sawhney1, H E Flores, A W Galston
1Department of Biology, Yale University, New Haven, Connecticut 06520.
Plant Physiology
|February 1, 1980
Summary
Oat leaf protoplasts can incorporate labeled molecules but do not divide. Polyamines stimulate DNA synthesis and cell division in these plant cells, suggesting a G1 arrest.
Area of Science:
- Plant Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Freshly isolated oat leaf protoplasts do not divide in culture.
- Protoplasts are plant cells with their cell walls removed, useful for studying cellular processes.
Purpose of the Study:
- To investigate the macromolecular synthesis capabilities of oat leaf protoplasts.
- To determine the effect of polyamines on protoplast division and DNA synthesis.
Main Methods:
- Culture of oat leaf protoplasts with tritiated leucine, uridine, and thymidine.
- Analysis of macromolecular incorporation using enzymatic hydrolysis (protease, RNase, DNase).
- Observation of cell division (mitoses) and multinucleation in cultured protoplasts.
- Treatment with diamines and polyamines to assess their impact on synthesis and division.
Main Results:
- Protoplasts incorporated leucine into protein and uridine into RNA.
- Thymidine incorporation into DNA was minimal initially and declined over time.
- Polyamines significantly increased thymidine incorporation into DNA and induced cell division.
Conclusions:
- Oat leaf protoplasts are arrested at the G1 phase of the cell cycle.
- Polyamines can overcome this arrest, promoting DNA synthesis and mitotic activity in oat protoplasts.
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